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Zhao C, Zhao J, Han J, Mei Y, Fang H. Improved consolidated bioprocessing for itaconic acid production by simultaneous optimization of cellulase and metabolic pathway of Neurospora crassa. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:57. [PMID: 38685114 PMCID: PMC11059683 DOI: 10.1186/s13068-024-02505-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 04/20/2024] [Indexed: 05/02/2024]
Abstract
Lignocellulose was directly used in itaconic acid production by a model filamentous fungus Neurospora crassa. The promoters of two clock control genes and cellobiohydrolase 1 gene were selected for heterologous genes expression by evaluating different types of promoters. The effect of overexpression of different cellulase was compared, and it was found that expression of cellobiohydrolase 2 from Trichoderma reesei increased the filter paper activity by 2 times, the cellobiohydrolase activity by 4.5 times, and that the itaconic acid titer was also significantly improved. A bidirectional cis-aconitic acid accumulation strategy was established by constructing the reverse glyoxylate shunt and expressing the transporter MTTA, which increased itaconic acid production to 637.2 mg/L. The simultaneous optimization of cellulase and metabolic pathway was more conducive to the improvement of cellulase activity than that of cellulase alone, so as to further increase itaconic acid production. Finally, through the combination of fermentation by optimized strains and medium optimization, the titers of itaconic acid using Avicel and corn stover as substrate were 1165.1 mg/L and 871.3 mg/L, respectively. The results prove the potential of the consolidated bioprocessing that directly converts lignocellulose to itaconic acid by a model cellulase synthesizing strain.
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Affiliation(s)
- Chen Zhao
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China.
- Biomass Energy Center for Arid and Semi-Arid Lands, Northwest A&F University, Yangling, 712100, Shaanxi, China.
| | - Jiajia Zhao
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
- The Second Department of Vaccine, Lanzhou Institute of Biological Products Co., Ltd., Lanzhou, 730046, China
| | - Jingjing Han
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
- Biomass Energy Center for Arid and Semi-Arid Lands, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Yaojie Mei
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
- Biomass Energy Center for Arid and Semi-Arid Lands, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Hao Fang
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China.
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, 733 Jianshe 3rd Road, Hangzhou, 311200, Zhejiang, China.
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2
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Jia J, Tan Y, Gao J, Han J, Shi P, Fang H, Zhao C. Cloning and expression of Neurospora crassa cellobiohydrolase II in Pichia pastoris. Protein Expr Purif 2024; 216:106416. [PMID: 38104790 DOI: 10.1016/j.pep.2023.106416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 12/07/2023] [Accepted: 12/09/2023] [Indexed: 12/19/2023]
Abstract
A major cellobiohydrolase of Neurospora crassa CBH2 was successfully expressed in Pichia pastoris. The maximum Avicelase activity in shake flask among seven transformants which selected on 4.0 g/L G418 plates was 0.61 U/mL. The optimal pH and temperature for Avicelase activity of the recombinant CBH2 were determined to be 4.8 and 60 °C, respectively. The new CBH2 maintained 63.5 % Avicelase activity in the range of pH 4.0-10.4, and 60.2 % Avicelase activity in the range of 30-90 °C. After incubation at 70-90 °C for 1 h, the Avicelase activity retained 60.5 % of its initial activity. The presence of Zn2+, Ca2+ or Cd2+ enhanced the Avicelase activity of the CBH2, of which Cd2+ at 10 mM causing the highest increase. The recombinant CBH2 was used to enhance the Avicel hydrolysis by improving the exo-exo-synergism between CBH2 and CBH1 in N.crassa cellulase. The enzymatic hydrolysis yield was increased by 38.1 % by adding recombinant CBH2 and CBH1, and the yield was increased by 215.4 % when the temperature is raised to 70 °C. This work provided a CBH2 with broader pH range and better heat resistance, which is a potential enzyme candidate in food, textile, pulp and paper industries, and other industrial fields.
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Affiliation(s)
- Jingsong Jia
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China; Biomass Energy Center for Arid and Semi-arid Lands, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Yu Tan
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China; Biomass Energy Center for Arid and Semi-arid Lands, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Jialun Gao
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China; Biomass Energy Center for Arid and Semi-arid Lands, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Jingjing Han
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China; Biomass Energy Center for Arid and Semi-arid Lands, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Peng Shi
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Hao Fang
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China; Biomass Energy Center for Arid and Semi-arid Lands, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China; ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, Zhejiang, China
| | - Chen Zhao
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China; Biomass Energy Center for Arid and Semi-arid Lands, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China.
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3
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Poltorak A, Zhou X, Kasuga T, Xu Y, Fan Z. Conversion of Deproteinized Cheese Whey to Lactobionate by an Engineered Neurospora crassa Strain F5. Appl Biochem Biotechnol 2024; 196:1292-1303. [PMID: 37392323 DOI: 10.1007/s12010-023-04583-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2023] [Indexed: 07/03/2023]
Abstract
We report a novel production process for lactobionic acid (LBA) production using an engineered Neurospora crassa strain F5. The wild-type N. crassa strain produces cellobiose dehydrogenase (CDH) and uses lactose as a carbon source. N. crassa strain F5, which was constructed by deleting six out of the seven β-glucosidases in the wild type, showed a much slower lactose utilization rate and produced a much higher level of cellobiose dehydrogenase (CDH) than the wild type. Strain N. crassa F5 produced CDH and laccase simultaneously on the pretreated wheat straw with 3 µM of cycloheximide added as the laccase inducer. The deproteinized cheese whey was added directly to the shake flasks with the fungus present to achieve LBA production. Strain F5 produced about 37 g/L of LBA from 45 g/L of lactose in 27 h since deproteinized cheese whey addition. The yield of LBA from consumed lactose was about 85%, and the LBA productivity achieved was about 1.37 g/L/h.
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Affiliation(s)
- Adam Poltorak
- Department of Biological and Agricultural Engineering, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Xin Zhou
- Department of Biological and Agricultural Engineering, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, People's Republic of China
| | - Takao Kasuga
- Department of Plant Pathology, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
- United States Department of Agriculture-Agricultural Research Service, Davis, CA, 95616, USA
| | - Yong Xu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, People's Republic of China
| | - Zhiliang Fan
- Department of Biological and Agricultural Engineering, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA.
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Zhou Y, Shi Y, Huang Y, Zhong J. Microbes on the "peachy spots" of ancient Kaihua paper: microbial community and functional analysis. Front Microbiol 2024; 14:1326835. [PMID: 38274746 PMCID: PMC10808800 DOI: 10.3389/fmicb.2023.1326835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 12/26/2023] [Indexed: 01/27/2024] Open
Abstract
Kaihua paper is a type of precious hand-made paper in China that has been used throughout Chinese history. Due to its extraordinary whiteness and fine texture, it was adopted by the imperial palace in the reign of Emperor Kang Xi and Yong Zheng of the Qing Dynasty of China in the 17th and 18th century. It is stained by a special type of yellowish-brown spot after years of storage, which is called a "peachy spot." The formation of such spots remains unclear, although complicated physicochemical processes or microbial activities might be involved. We performed nondestructive sampling and high-throughput sequencing on peachy spot surfaces, unstained areas, and air samples in the stack room to analysis the the bacterial and fungal communities, and performed prediction of functional genes of the bacterial communities. The results showed that peachy spot formation was mainly related to bacterial communities rather than fungal communities. Significantly more potential acid- producing, acidophilic or cellulase-producing bacteria, such as, Streptococcus, Staphylococcus, and Lysinibacillus, and pigment-producing bacteria, such as Methylobacterium and Rubrobacter, were identified in the peachy spot samples. Prediction of the functional genes of the bacterial community also suggested the production of acidic substance pigments. These findings provide new insights into the pigment formation mechanism in ancient paper and open an opportunity to develop new strategies to preserve the ancient paper documents.
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Affiliation(s)
- Yanjun Zhou
- Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Yan Shi
- Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Yanyan Huang
- Institute for Preservation and Conservation of Chinese Ancient Books, Fudan University, Shanghai, China
| | - Jiang Zhong
- Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai, China
- Institute for Preservation and Conservation of Chinese Ancient Books, Fudan University, Shanghai, China
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5
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Zhang Y, Nada B, Baker SE, Evans JE, Tian C, Benz JP, Tamayo E. Unveiling a classical mutant in the context of the GH3 β-glucosidase family in Neurospora crassa. AMB Express 2024; 14:4. [PMID: 38180602 PMCID: PMC10770018 DOI: 10.1186/s13568-023-01658-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 12/23/2023] [Indexed: 01/06/2024] Open
Abstract
Classical fungal mutant strains obtained by mutagenesis have helped to elucidate fundamental metabolic pathways in the past. In the filamentous fungus Neurospora crassa, the gluc-1 strain was isolated long ago and characterized by its low level of β-glucosidase activity, which is essential for the degradation of cellulose, the most abundant biopolymer on Earth and the main polymeric component of the plant cell wall. Based on genomic resequencing, we hypothesized that the causative mutation resides in the β-glucosidase gene gh3-3 (bgl6, NCU08755). In this work, growth patterns, enzymatic activities and sugar utilization rates were analyzed in several mutant and overexpression strains related to gluc-1 and gh3-3. In addition, different mutants affected in the degradation and transport of cellobiose were analyzed. While overexpression of gh3-3 led to the recovery of β-glucosidase activity in the gluc-1 mutant, as well as normal utilization of cellobiose, the full gene deletion strain Δgh3-3 was found to behave differently than gluc-1 with lower secreted β-glucosidase activity, indicating a dominant role of the amino acid substitution in the point mutated gh3-3 gene of gluc-1. Our results furthermore confirm that GH3-3 is the major extracellular β-glucosidase in N. crassa and demonstrate that the two cellodextrin transporters CDT-1 and CDT-2 are essential for growth on cellobiose when the three main N. crassa β-glucosidases are absent. Overall, these findings provide valuable insight into the mechanisms of cellulose utilization in filamentous fungi, being an essential step in the efficient production of biorefinable sugars from agricultural and forestry plant biomass.
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Affiliation(s)
- Yuxin Zhang
- Fungal Biotechnology in Wood Science, Holzforschung München, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
| | - Basant Nada
- Fungal Biotechnology in Wood Science, Holzforschung München, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
| | - Scott E Baker
- DOE Joint BioEnergy Institute, Emeryville, CA, 94608, USA
- Microbial Molecular Phenotyping Group, Environmental Molecular Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - James E Evans
- Microbial Molecular Phenotyping Group, Environmental Molecular Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Chaoguang Tian
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - J Philipp Benz
- Fungal Biotechnology in Wood Science, Holzforschung München, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
| | - Elisabeth Tamayo
- Fungal Biotechnology in Wood Science, Holzforschung München, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany.
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Xue F, Zhao Z, Gu S, Chen M, Xu J, Luo X, Li J, Tian C. The transcriptional factor Clr-5 is involved in cellulose degradation through regulation of amino acid metabolism in Neurospora crassa. BMC Biotechnol 2023; 23:50. [PMID: 38031036 PMCID: PMC10687990 DOI: 10.1186/s12896-023-00823-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 11/23/2023] [Indexed: 12/01/2023] Open
Abstract
BACKGROUND Filamentous fungi are efficient degraders of plant biomass and the primary producers of commercial cellulolytic enzymes. While the transcriptional regulation mechanisms of cellulases have been continuously explored in lignocellulolytic fungi, the induction of cellulase production remains a complex multifactorial system, with several aspects still largely elusive. RESULTS In this study, we identified a Zn2Cys6 transcription factor, designated as Clr-5, which regulates the expression of cellulase genes by influencing amino acid metabolism in Neurospora crassa during growth on cellulose. The deletion of clr-5 caused a significant decrease in secreted protein and cellulolytic enzyme activity of N. crassa, which was partially alleviated by supplementing with yeast extract. Transcriptomic profiling revealed downregulation of not only the genes encoding main cellulases but also those related to nitrogen metabolism after disruption of Clr-5 under Avicel condition. Clr-5 played a crucial role in the utilization of multiple amino acids, especially leucine and histidine. When using leucine or histidine as the sole nitrogen source, the Δclr-5 mutant showed significant growth defects on both glucose and Avicel media. Comparative transcriptomic analysis revealed that the transcript levels of most genes encoding carbohydrate-active enzymes and those involved in the catabolism and uptake of histidine, branched-chain amino acids, and aromatic amino acids, were remarkably reduced in strain Δclr-5, compared with the wild-type N. crassa when grown in Avicel medium with leucine or histidine as the sole nitrogen source. These findings underscore the important role of amino acid metabolism in the regulation of cellulase production in N. crassa. Furthermore, the function of Clr-5 in regulating cellulose degradation is conserved among ascomycete fungi. CONCLUSIONS These findings regarding the novel transcription factor Clr-5 enhance our comprehension of the regulatory connections between amino acid metabolism and cellulase production, offering fresh prospects for the development of fungal cell factories dedicated to cellulolytic enzyme production in bio-refineries.
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Affiliation(s)
- Fanglei Xue
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Zhen Zhao
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Shuying Gu
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Meixin Chen
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Jing Xu
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Xuegang Luo
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Jingen Li
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.
| | - Chaoguang Tian
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.
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Motycka B, Csarman F, Tscheliessnig R, Hammel M, Ludwig R. Resolving domain positions of cellobiose dehydrogenase by small angle X-ray scattering. FEBS J 2023; 290:4726-4743. [PMID: 37287434 PMCID: PMC10592539 DOI: 10.1111/febs.16885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 05/16/2023] [Accepted: 06/06/2023] [Indexed: 06/09/2023]
Abstract
The interdomain electron transfer (IET) between the catalytic flavodehydrogenase domain and the electron-transferring cytochrome domain of cellobiose dehydrogenase (CDH) plays an essential role in biocatalysis, biosensors and biofuel cells, as well as in its natural function as an auxiliary enzyme of lytic polysaccharide monooxygenase. We investigated the mobility of the cytochrome and dehydrogenase domains of CDH, which is hypothesised to limit IET in solution by small angle X-ray scattering (SAXS). CDH from Myriococcum thermophilum (syn. Crassicarpon hotsonii, syn. Thermothelomyces myriococcoides) was probed by SAXS to study the CDH mobility at different pH and in the presence of divalent cations. By comparison of the experimental SAXS data, using pair-distance distribution functions and Kratky plots, we show an increase in CDH mobility at higher pH, indicating alterations of domain mobility. To further visualise CDH movement in solution, we performed SAXS-based multistate modelling. Glycan structures present on CDH partially masked the resulting SAXS shapes, we diminished these effects by deglycosylation and studied the effect of glycoforms by modelling. The modelling shows that with increasing pH, the cytochrome domain adopts a more flexible state with significant separation from the dehydrogenase domain. On the contrary, the presence of calcium ions decreases the mobility of the cytochrome domain. Experimental SAXS data, multistate modelling and previously reported kinetic data show how pH and divalent ions impact the closed state necessary for the IET governed by the movement of the CDH cytochrome domain.
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Affiliation(s)
- Bettina Motycka
- University of Natural Resources and Life Sciences, Vienna, Department of Food Science and Technology, Institute of Food Technology, Muthgasse 18, 1190 Vienna, Austria
- University of Natural Resources and Life Sciences, Vienna, Department of Biotechnology, Institute of Bioprocess Science and Engineering, Muthgasse 18, 1190 Vienna, Austria
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkely, California, USA
| | - Florian Csarman
- University of Natural Resources and Life Sciences, Vienna, Department of Food Science and Technology, Institute of Food Technology, Muthgasse 18, 1190 Vienna, Austria
| | - Rupert Tscheliessnig
- University of Natural Resources and Life Sciences, Vienna, Department of Biotechnology, Institute of Bioprocess Science and Engineering, Muthgasse 18, 1190 Vienna, Austria
- Division of Biophysics, Gottfried-Schatz-Research-Center, Medical University of Graz, Graz, Austria
| | - Michal Hammel
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkely, California, USA
| | - Roland Ludwig
- University of Natural Resources and Life Sciences, Vienna, Department of Food Science and Technology, Institute of Food Technology, Muthgasse 18, 1190 Vienna, Austria
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Baruah D, Tamuli R. The cell functions of phospholipase C-1, Ca 2+/H + exchanger-1, and secretory phospholipase A 2 in tolerance to stress conditions and cellulose degradation in Neurospora crassa. Arch Microbiol 2023; 205:327. [PMID: 37676310 DOI: 10.1007/s00203-023-03662-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 08/13/2023] [Accepted: 08/17/2023] [Indexed: 09/08/2023]
Abstract
We investigated the cell functions of the Ca2+ signaling genes phospholipase C-1 (plc-1), Ca2+/H+ exchanger (cpe-1), and secretory phospholipase A2 (splA2) for stress responses and cellulose utilization in Neurospora crassa. The Δplc-1, Δcpe-1, and ΔsplA2 mutants displayed increased sensitivity to the alkaline pH and reduced survival during induced thermotolerance. The ΔsplA2 mutant also exhibited hypersensitivity to the DTT-induced endoplasmic reticulum (ER) stress, increased microcrystalline cellulose utilization, increased protein secretion, and glucose accumulation in the culture supernatants. Moreover, the ΔsplA2 mutant could not grow on microcrystalline cellulose during ER stress. Furthermore, plc-1, cpe-1, and splA2 synthetically regulate the acquisition of thermotolerance induced by heat shock, responses to alkaline pH and ER stress, and utilization of cellulose and other alternate carbon sources in N. crassa. In addition, expression of the alkaline pH regulator, pac-3, and heat shock proteins, hsp60, and hsp80 was reduced in the Δplc-1, Δcpe-1, and ΔsplA2 single and double mutants. The expression of the unfolded protein response (UPR) markers grp-78 and pdi-1 was also significantly reduced in the mutants showing growth defect during ER stress. The increased cellulolytic activities of the ΔsplA2 and Δcpe-1; ΔsplA2 mutants were due to increased cbh-1, cbh-2, and endo-2 expression in N. crassa. Therefore, plc-1, cpe-1, and splA2 are involved in stress responses and cellulose utilization in N. crassa.
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Affiliation(s)
- Darshana Baruah
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781 039, India
| | - Ranjan Tamuli
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781 039, India.
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Zhang Y, Sun T, Wu T, Li J, Hu D, Liu D, Li J, Tian C. Consolidated bioprocessing for bioethanol production by metabolically engineered cellulolytic fungus Myceliophthora thermophila. Metab Eng 2023; 78:192-199. [PMID: 37348810 DOI: 10.1016/j.ymben.2023.06.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 06/14/2023] [Accepted: 06/18/2023] [Indexed: 06/24/2023]
Abstract
Using cellulosic ethanol as fuel is one way to help achieve the world's decarbonization goals. However, the economics of the present technology are unfavorable, especially the cost of cellulose degradation. Here, we reprogram the thermophilic cellulosic fungus Myceliophthora thermophila to directly ferment cellulose into ethanol by mimicking the aerobic ethanol fermentation of yeast (the Crabtree effect), including optimizing the synthetic pathway, enhancing the glycolytic rate, inhibiting mitochondrial NADH shuttles, and knocking out ethanol consumption pathway. The final engineered strain produced 52.8 g/L ethanol directly from cellulose, and 39.8 g/L from corncob, without the need for any added cellulase, while the starting strain produced almost no ethanol. We also demonstrate that as the ethanol fermentation by engineered M. thermophila increases, the composition and expression of cellulases that facilitate the degradation of cellulose, especially cellobiohydrolases, changes. The simplified production process and significantly increased ethanol yield indicate that the fungal consolidated bioprocessing technology that we develop here (one-step, one-strain ethanol production) is promising for fueling sustainable carbon-neutral biomanufacturing in the future.
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Affiliation(s)
- Yongli Zhang
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China; National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.
| | - Tao Sun
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China; National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.
| | - Taju Wu
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China; National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.
| | - Jinyang Li
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China; National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.
| | - Die Hu
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China; National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.
| | - Defei Liu
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China; National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.
| | - Jingen Li
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China; National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.
| | - Chaoguang Tian
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China; National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.
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Tramontina R, Ciancaglini I, Roman EKB, Chacón MG, Corrêa TLR, Dixon N, Bugg TDH, Squina FM. Sustainable biosynthetic pathways to value-added bioproducts from hydroxycinnamic acids. Appl Microbiol Biotechnol 2023:10.1007/s00253-023-12571-8. [PMID: 37212882 DOI: 10.1007/s00253-023-12571-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 05/01/2023] [Accepted: 05/05/2023] [Indexed: 05/23/2023]
Abstract
The biorefinery concept, in which biomass is utilized for the production of fuels and chemicals, emerges as an eco-friendly, cost-effective, and renewable alternative to petrochemical-based production. The hydroxycinnamic acid fraction of lignocellulosic biomass represents an untapped source of aromatic molecules that can be converted to numerous high-value products with industrial applications, including in the flavor and fragrance sector and pharmaceuticals. This review describes several biochemical pathways useful in the development of a biorefinery concept based on the biocatalytic conversion of the hydroxycinnamic acids ferulic, caffeic, and p-coumaric acid into high-value molecules. KEY POINTS: • The phenylpropanoids bioconversion pathways in the context of biorefineries • Description of pathways from hydroxycinnamic acids to high-value compounds • Metabolic engineering and synthetic biology advance hydroxycinnamic acid-based biorefineries.
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Affiliation(s)
- Robson Tramontina
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- Programa de Processos Tecnológicos E Ambientais, Universidade de Sorocaba (UNISO), Sorocaba, São Paulo, Brazil
| | - Iara Ciancaglini
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Ellen K B Roman
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Micaela G Chacón
- Manchester Institute of Biotechnology (MIB), Department of Chemistry, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - Thamy L R Corrêa
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Neil Dixon
- Manchester Institute of Biotechnology (MIB), Department of Chemistry, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - Timothy D H Bugg
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
| | - Fabio Marcio Squina
- Programa de Processos Tecnológicos E Ambientais, Universidade de Sorocaba (UNISO), Sorocaba, São Paulo, Brazil.
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11
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Gu S, Zhao Z, Xue F, Liu D, Liu Q, Li J, Tian C. The arabinose transporter MtLat-1 is involved in hemicellulase repression as a pentose transceptor in Myceliophthora thermophila. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:51. [PMID: 36966330 PMCID: PMC10040116 DOI: 10.1186/s13068-023-02305-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 03/20/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Filamentous fungi possess an array of secreted enzymes to depolymerize the structural polysaccharide components of plant biomass. Sugar transporters play an essential role in nutrient uptake and sensing of extracellular signal molecules to inhibit or trigger the induction of lignocellulolytic enzymes. However, the identities and functions of transceptors associated with the induction of hemicellulase genes remain elusive. RESULTS In this study, we reveal that the L-arabinose transporter MtLat-1 is associated with repression of hemicellulase gene expression in the filamentous fungus Myceliophthora thermophila. The absence of Mtlat-1 caused a decrease in L-arabinose uptake and consumption rates. However, mycelium growth, protein production, and hemicellulolytic activities were markedly increased in a ΔMtlat-1 mutant compared with the wild-type (WT) when grown on arabinan. Comparative transcriptomic analysis showed a different expression profile in the ΔMtlat-1 strain from that in the WT in response to arabinan, and demonstrated that MtLat-1 was involved in the repression of the main hemicellulase-encoding genes. A point mutation that abolished the L-arabinose transport activity of MtLat-1 did not impact the repression of hemicellulase gene expression when the mutant protein was expressed in the ΔMtlat-1 strain. Thus, the involvement of MtLat-1 in the expression of hemicellulase genes is independent of its transport activity. The data suggested that MtLat-1 is a transceptor that senses and transduces the molecular signal, resulting in downstream repression of hemicellulolytic gene expression. MtAra-1 protein directly regulated the expression of Mtlat-1 by binding to its promoter region. Transcriptomic profiling indicated that the transcription factor MtAra-1 also plays an important role in expression of arabinanolytic enzyme genes and L-arabinose catabolism. CONCLUSIONS M. thermophila MtLat-1 functions as a transceptor that is involved in L-arabinose transport and signal transduction associated with suppression of the expression of hemicellulolytic enzyme-encoding genes. The data presented in this study add to the models of the regulation of hemicellulases in filamentous fungi.
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Affiliation(s)
- Shuying Gu
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Zhen Zhao
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Fanglei Xue
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457 China
| | - Defei Liu
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Qian Liu
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Jingen Li
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Chaoguang Tian
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
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12
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Developing a Temperature-Inducible Transcriptional Rheostat in Neurospora crassa. mBio 2023; 14:e0329122. [PMID: 36744948 PMCID: PMC9973361 DOI: 10.1128/mbio.03291-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Heat shock protein (HSP)-encoding genes (hsp), part of the highly conserved heat shock response (HSR), are known to be induced by thermal stress in several organisms. In Neurospora crassa, three hsp genes, hsp30, hsp70, and hsp80, have been characterized; however, the role of defined cis elements in their responses to discrete changes in temperature remains largely unexplored. To fill this gap, while also aiming to obtain a reliable fungal heat shock-inducible system, we analyzed different sections of each hsp promoter by assessing the expression of real-time transcriptional reporters. Whereas all three promoters and their resected versions were acutely induced by high temperatures, only hsp30 displayed a broad range of expression and high tunability, amply exceeding other inducible promoter systems existing in Neurospora, such as quinic acid- or light-inducible ones. As proof of concept, we employed one of these promoters to control the expression of clr-2, which encodes the master regulator of Neurospora cellulolytic capabilities. The resulting strain fails to grow on cellulose at 25°C, whereas it grows robustly if heat shock pulses are delivered daily. Additionally, we designed two hsp30 synthetic promoters and characterized them, as well as the native promoters, using a gradient of high temperatures, yielding a wide range of responses to thermal stimuli. Thus, Neurospora hsp30-based promoters represent a new set of modular elements that can be used as transcriptional rheostats to adjust the expression of a gene of interest or for the implementation of regulated circuitries for synthetic biology and biotechnological strategies. IMPORTANCE A timely and dynamic response to strong temperature fluctuations is paramount for organismal biology. At the same time, inducible promoters are a powerful tool for fungal biotechnological and synthetic biology endeavors. In this work, we analyzed the activity of several N. crassa heat shock protein (hsp) promoters at a wide range of temperatures, observing that hsp30 exhibits remarkable sensitivity and a dynamic range of expression as we charted the response of this promoter to subtle increases in temperature, and also as we built and analyzed synthetic promoters based on hsp30 cis elements. As proof of concept, we tested the ability of hsp30 to provide tight control of a central process, cellulose degradation. While this study provides an unprecedented description of the regulation of the N. crassa hsp genes, it also contributes a noteworthy addition to the molecular toolset of transcriptional controllers in filamentous fungi.
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Effect of itaconic acid production on Neurospora crassa in consolidated bioprocessing of cellulose. Microb Cell Fact 2023; 22:28. [PMID: 36774527 PMCID: PMC9922455 DOI: 10.1186/s12934-023-02034-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Accepted: 02/03/2023] [Indexed: 02/13/2023] Open
Abstract
A system for itaconic acid synthesis from cellulose by Neurospora crassa was established, resulting in the highest yield of itaconic acid was 354.08 + 35.99 mg/L. Meanwhile, cellulase activity increased significantly, without any strain modifications for improved cellulase production. Multi-omics analyses showed that itaconic acid synthesis reduced energy production, leading to decreases in trehalose, cell wall, fatty acids synthesis and downregulations in MAPK signaling pathway, cell cycle and meiosis. More importantly, the low-energy environment enhanced the energy-efficient cellobionic acid/gluconic acid pathway, and the cellulase composition also changed significantly, manifested as the up-regulation of LPMOs and the down-regulation of β-glucosidases. Enhancing LPMOs-cellobionic acid/gluconic acid system has the potential to reduce energy consumption of the consolidated bioprocessing. These findings offer an overview of resource allocations by N. crassa in response to itaconic acid synthesis and highlight a series of intriguing connections between itaconic acid synthesis and cellulase synthesis in consolidated bioprocessing.
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14
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Liu D, Zhang Y, Li J, Sun W, Yao Y, Tian C. The Weimberg pathway: an alternative for Myceliophthora thermophila to utilize D-xylose. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:13. [PMID: 36691040 PMCID: PMC9869559 DOI: 10.1186/s13068-023-02266-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 01/13/2023] [Indexed: 01/24/2023]
Abstract
BACKGROUND With D-xylose being the second most abundant sugar in nature, its conversion into products could significantly improve biomass-based process economy. There are two well-studied phosphorylative pathways for D-xylose metabolism. One is isomerase pathway mainly found in bacteria, and the other one is oxo-reductive pathway that always exists in fungi. Except for these two pathways, there are also non-phosphorylative pathways named xylose oxidative pathways and they have several advantages over traditional phosphorylative pathways. In Myceliophthora thermophila, D-xylose can be metabolized through oxo-reductive pathway after plant biomass degradation. The survey of non-phosphorylative pathways in this filamentous fungus will offer a potential way for carbon-efficient production of fuels and chemicals using D-xylose. RESULTS In this study, an alternative for utilization of D-xylose, the non-phosphorylative Weimberg pathway was established in M. thermophila. Growth on D-xylose of strains whose D-xylose reductase gene was disrupted, was restored after overexpression of the entire Weimberg pathway. During the construction, a native D-xylose dehydrogenase with highest activity in M. thermophila was discovered. Here, M. thermophila was also engineered to produce 1,2,4-butanetriol using D-xylose through non-phosphorylative pathway. Afterwards, transcriptome analysis revealed that the D-xylose dehydrogenase gene was obviously upregulated after deletion of D-xylose reductase gene when cultured in a D-xylose medium. Besides, genes involved in growth were enriched in strains containing the Weimberg pathway. CONCLUSIONS The Weimberg pathway was established in M. thermophila to support its growth with D-xylose being the sole carbon source. Besides, M. thermophila was engineered to produce 1,2,4-butanetriol using D-xylose through non-phosphorylative pathway. To our knowledge, this is the first report of non-phosphorylative pathway recombinant in filamentous fungi, which shows great potential to convert D-xylose to valuable chemicals.
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Affiliation(s)
- Defei Liu
- grid.9227.e0000000119573309Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China ,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Yongli Zhang
- grid.9227.e0000000119573309Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China ,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Jingen Li
- grid.9227.e0000000119573309Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China ,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Wenliang Sun
- grid.9227.e0000000119573309Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China ,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Yonghong Yao
- grid.9227.e0000000119573309Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China ,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Chaoguang Tian
- grid.9227.e0000000119573309Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China ,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
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15
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Wang H, Pang AP, Wang W, Li B, Li C, Wu FG, Lin F. Discovery of ER-localized sugar transporters for cellulase production with lac1 being essential. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:132. [PMID: 36443855 PMCID: PMC9706901 DOI: 10.1186/s13068-022-02230-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 11/12/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND In the process of cellulose hydrolysis, carbohydrate hydrolysates are transported into cells through membrane transporters, and then affect the expression of cellulase-encoding genes. Sugar transporters play a crucial role in cellulase production in lignocellulolytic fungi, of which relatively few have been functionally validated to date and are all reported to be on cell membrane. RESULT Through transcriptome analysis and qRT-PCR, three putative MFS sugar transporters GST, MFS, and LAC1 were found to display significantly higher mRNA levels in T. reesei grown on cellulose than on glucose. The individual deletion of these three genes compromised cellulase production and delayed sugar absorption by 24 h in T. reesei. Nevertheless, they transported pretty low level of sugars, including galactose, lactose, and mannose, and did not transport glucose, when expressed in yeast system. Meanwhile, all three transporters were unexpectedly found to be intracellular, being located in endoplasmic reticulum (ER). Particularly, the knockout of lac1 almost abolished cellulase production, and significantly inhibited biomass generation regardless of sugar types, indicating that lac1 is essential for cellulase production and biomass formation. The absence of lac1 upregulated genes involved in ribosome biogenesis, while downregulated genes in cellulase production, protein processing in ER (particularly protein glycosylation), and lipid biosynthesis. The inhibition of lac1 deletion on the transcriptional levels of genes related to cellulase biosynthesis was restored after 72 h, but the cellulase production was still inhibited, indicating lac1 might pose a post-transcription regulation on cellulase production that are independent on the known cellulase regulation mediated by CRT1 and XYR1. CONCLUSION For the first time, intracellular sugar transporters (mfs, gst, and lac1) facilitating cellulase production were identified, which was distributed in ER. Their sugar transporting ability was very weak, indicating that they might be related to sugar utilization inside cells rather than the cellular sugar uptake. More importantly, sugar transporter lac1 is first found to be essential for cellulase production and biomass formation by affecting protein processing in ER (particularly protein glycosylation) and lipid biosynthesis. The effect of LAC1 on cellulase production seems to be post-transcriptional at late stage of cellulase production, independent on the well-known cellulase regulation mediated by CRT1 and XYR1. These findings improve the understanding of intracellular sugar transporters in fungi and their important role in cellulase synthesis.
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Affiliation(s)
- Haiyan Wang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Ai-Ping Pang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Wei Wang
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Bingzhi Li
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Chengcheng Li
- School of Light Ind. & Food Sci. and Joint International Research Lab of Lignocellulosic Functional Materials, Nanjing Forestry University, Nanjing, 210037, China
| | - Fu-Gen Wu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Fengming Lin
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China.
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16
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Qin X, Zou J, Yang K, Li J, Wang X, Tu T, Wang Y, Yao B, Huang H, Luo H. Deciphering the efficient cellulose degradation by the thermophilic fungus Myceliophthora thermophila focused on the synergistic action of glycoside hydrolases and lytic polysaccharide monooxygenases. BIORESOURCE TECHNOLOGY 2022; 364:128027. [PMID: 36174898 DOI: 10.1016/j.biortech.2022.128027] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/20/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
The thermophilic fungus Myceliophthora thermophila as an efficient decomposer secretes various glycoside hydrolases and auxiliary oxidation enzymes to deconstruct cellulose. However, the core enzymes critical for efficient cellulose degradation and their interactions with other cellulolytic enzymes remain unclear. Herein, the transcriptomic analysis of M. thermophila grown on Avicel exhibited that cellulases from GH5_5, GH6 and GH7, and lytic polysaccharide monooxygenases (LPMOs) from AA9 contributed to cellulose degradation. Moreover, the peptide mass fingerprinting analysis of major extracellular proteins and corresponding gene-knockout strains studies revealed that MtCel7A and MtCel5A were the core cellulolytic enzymes. Furthermore, synergistic experiments found that hydrolytic efficiencies of MtCel7A and MtCel5A were both improved by mixture C1/C4 oxidizing MtLPMO9H, but inhibited by C1 oxidizing MtLPMO9E and C4 oxidizing MtLPMO9J respectively. These results demonstrated the potential application of C1/C4 oxidizing LPMOs for future designing novel cellulolytic enzyme cocktails on the efficient conversion of cellulose into biofuels and biochemicals.
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Affiliation(s)
- Xing Qin
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jiahuan Zou
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Kun Yang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jinyang Li
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xiaolu Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Tao Tu
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yuan Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Bin Yao
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Huoqing Huang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Huiying Luo
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
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17
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Identifying the gluc-1 and gluc-2 mutations in Neurospora crassa by genome resequencing. J Genet 2022. [DOI: 10.1007/s12041-022-01394-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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18
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Chang H, Gacias Amengual N, Botz A, Schwaiger L, Kracher D, Scheiblbrandner S, Csarman F, Ludwig R. Investigating lytic polysaccharide monooxygenase-assisted wood cell wall degradation with microsensors. Nat Commun 2022; 13:6258. [PMID: 36271009 PMCID: PMC9586961 DOI: 10.1038/s41467-022-33963-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 10/10/2022] [Indexed: 12/25/2022] Open
Abstract
Lytic polysaccharide monooxygenase (LPMO) supports biomass hydrolysis by increasing saccharification efficiency and rate. Recent studies demonstrate that H2O2 rather than O2 is the cosubstrate of the LPMO-catalyzed depolymerization of polysaccharides. Some studies have questioned the physiological relevance of the H2O2-based mechanism for plant cell wall degradation. This study reports the localized and time-resolved determination of LPMO activity on poplar wood cell walls by measuring the H2O2 concentration in their vicinity with a piezo-controlled H2O2 microsensor. The investigated Neurospora crassa LPMO binds to the inner cell wall layer and consumes enzymatically generated H2O2. The results point towards a high catalytic efficiency of LPMO at a low H2O2 concentration that auxiliary oxidoreductases in fungal secretomes can easily generate. Measurements with a glucose microbiosensor additionally demonstrate that LPMO promotes cellobiohydrolase activity on wood cell walls and plays a synergistic role in the fungal extracellular catabolism and in industrial biomass degradation.
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Affiliation(s)
- Hucheng Chang
- grid.5173.00000 0001 2298 5320Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Neus Gacias Amengual
- grid.5173.00000 0001 2298 5320Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Alexander Botz
- grid.5173.00000 0001 2298 5320Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Lorenz Schwaiger
- grid.5173.00000 0001 2298 5320Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Daniel Kracher
- grid.5173.00000 0001 2298 5320Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria ,grid.410413.30000 0001 2294 748XPresent Address: Institute of Molecular Biotechnology, Graz University of Technology, Petersgasse 14, 8010 Graz, Austria
| | - Stefan Scheiblbrandner
- grid.5173.00000 0001 2298 5320Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Florian Csarman
- grid.5173.00000 0001 2298 5320Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Roland Ludwig
- grid.5173.00000 0001 2298 5320Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
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Cabrera IE, Oza Y, Carrillo AJ, Collier LA, Wright SJ, Li L, Borkovich KA. Regulator of G Protein Signaling Proteins Control Growth, Development and Cellulase Production in Neurospora crassa. J Fungi (Basel) 2022; 8:jof8101076. [PMID: 36294641 PMCID: PMC9604755 DOI: 10.3390/jof8101076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/05/2022] [Accepted: 10/11/2022] [Indexed: 11/30/2022] Open
Abstract
Heterotrimeric (αβγ) G protein signaling pathways are critical environmental sensing systems found in eukaryotic cells. Exchange of GDP for GTP on the Gα subunit leads to its activation. In contrast, GTP hydrolysis on the Gα is accelerated by Regulator of G protein Signaling (RGS) proteins, resulting in a return to the GDP-bound, inactive state. Here, we analyzed growth, development and extracellular cellulase production in strains with knockout mutations in the seven identified RGS genes (rgs-1 to rgs-7) in the filamentous fungus, Neurospora crassa. We compared phenotypes to those of strains with either knockout mutations or expressing predicted constitutively activated, GTPase-deficient alleles for each of the three Gα subunit genes (gna-1Q204L, gna-2Q205L or gna-3Q208L). Our data revealed that six RGS mutants have taller aerial hyphae than wild type and all seven mutants exhibit reduced asexual sporulation, phenotypes shared with strains expressing the gna-1Q204L or gna-3Q208L allele. In contrast, Δrgs-1 and Δrgs-3 were the only RGS mutants with a slower growth rate phenotype, a defect in common with gna-1Q204L strains. With respect to female sexual development, Δrgs-1 possessed defects most similar to gna-3Q208L strains, while those of Δrgs-2 mutants resembled strains expressing the gna-1Q204L allele. Finally, we observed that four of the seven RGS mutants had significantly different extracellular cellulase levels relative to wild type. Of interest, the Δrgs-2 mutant had no detectable activity, similar to the gna-3Q208L strain. In contrast, the Δrgs-1 and Δrgs-4 mutants and gna-1Q204L and gna-2Q205L strains exhibited significantly higher cellulase activity than wild type. With the exception of sexual development, our results demonstrate the greatest number of genetic interactions between rgs-1 and gna-1 and rgs-2 and gna-3 in N. crassa.
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20
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Yu NN, Ketya W, Choi EH, Park G. Plasma Promotes Fungal Cellulase Production by Regulating the Levels of Intracellular NO and Ca 2. Int J Mol Sci 2022; 23:6668. [PMID: 35743111 PMCID: PMC9223429 DOI: 10.3390/ijms23126668] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 06/12/2022] [Accepted: 06/14/2022] [Indexed: 12/04/2022] Open
Abstract
For the industrial-scale production of useful enzymes by microorganisms, technological development is required for overcoming a technical bottleneck represented by poor efficiency in the induction of enzyme gene expression and secretion. In this study, we evaluated the potential of a non-thermal atmospheric pressure plasma jet to improve the production efficiency of cellulolytic enzymes in Neurospora crassa, a filamentous fungus. The total activity of cellulolytic enzymes and protein concentration were significantly increased (1.1~1.2 times) in media containing Avicel 24-72 h after 2 and 5 min of plasma treatment. The mRNA levels of four cellulolytic enzymes in fungal hyphae grown in media with Avicel were significantly increased (1.3~17 times) 2-4 h after a 5 min of plasma treatment. The levels of intracellular NO and Ca2+ were increased in plasma-treated fungal hyphae grown in Avicel media after 48 h, and the removal of intracellular NO decreased the activity of cellulolytic enzymes in media and the level of vesicles in fungal hyphae. Our data suggest that plasma treatment can promote the transcription and secretion of cellulolytic enzymes into the culture media in the presence of Avicel (induction condition) by enhancing the intracellular level of NO and Ca2+.
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Affiliation(s)
- Nan-Nan Yu
- Plasma Bioscience Research Center and Department of Plasma-Bio Display, Kwangwoon University, Seoul 01897, Korea; (N.-N.Y.); (W.K.); (E.-H.C.)
| | - Wirinthip Ketya
- Plasma Bioscience Research Center and Department of Plasma-Bio Display, Kwangwoon University, Seoul 01897, Korea; (N.-N.Y.); (W.K.); (E.-H.C.)
| | - Eun-Ha Choi
- Plasma Bioscience Research Center and Department of Plasma-Bio Display, Kwangwoon University, Seoul 01897, Korea; (N.-N.Y.); (W.K.); (E.-H.C.)
- Department of Electrical and Biological Physics, Kwangwoon University, Seoul 01897, Korea
| | - Gyungsoon Park
- Plasma Bioscience Research Center and Department of Plasma-Bio Display, Kwangwoon University, Seoul 01897, Korea; (N.-N.Y.); (W.K.); (E.-H.C.)
- Department of Electrical and Biological Physics, Kwangwoon University, Seoul 01897, Korea
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21
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Dong M, Wang S, Xu F, Xiao G, Bai J, Wang J, Sun X. Integrative transcriptome and proteome analyses of Trichoderma longibrachiatum LC and its cellulase hyper-producing mutants generated by heavy ion mutagenesis reveal the key genes involved in cellulolytic enzymes regulation. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:63. [PMID: 35658919 PMCID: PMC9166314 DOI: 10.1186/s13068-022-02161-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 05/18/2022] [Indexed: 01/10/2023]
Abstract
Background The major challenge of facing the efficient utilization of biomass is the high cost of cellulolytic enzyme, while the Trichoderma longibrachiatum plays an essential role in the production of industrial enzymes and biomass recycling. Results The cellulase hyper‑producing mutants of LC-M4 and LC-M16 derived from the wild type T. longibrachiatum LC strain through heavy ion mutagenesis exhibited the high-efficiency secretion ability of cellulase and hemicellulose. The FPase activities of LC-M4 (4.51 IU/mL) and LC-M16 (4.16 IU/mL) mutants increased by 46.91% and 35.5% when compared to the LC strain, respectively. Moreover, these two cellulase hyper-producing mutants showed faster growth rate on the cellulosic substrates (Avicel and CMC-Na) plate than that of LC strain. Therefore, an integrative transcriptome and proteome profiling analysis of T. longibrachiatum LC and its cellulase hyper‑producing mutant LC-M4 and LC-M16 were employed to reveal the key genes involved in cellulolytic enzymes regulation. It was showed that the transcriptome and proteome profiles changed dramatically between the wild strain and mutant strains. Notably, the overlapped genes obtained from integrative analysis identified that the protein processing in ER involved in protein secretory pathway, starch and sucrose metabolism pathway and N-glycan biosynthesis pathway were significantly changed both in cellulase hyper-producing mutants and thereby improving the enzyme secretion efficiency, which maybe the main reason of cellulase hyper-production in LC-M4 and LC-M16 mutants. In addition, the three DEGs/DEPs (PDI, Sec61, VIP36) related with protein secretion in ER and two DEGs/DEPs (OST, MOGS) related with N-glycan biosynthesis were identified as key candidate genes participating in enzyme protein biosynthesis and secretion. Conclusions In this study, a hypothetical secretory model of cellulase protein in filamentous fungi was established on the basis of DEGs/DEPs and key genes identified from the omics analysis, which were of great guidance on the rational genetic engineering and/or breeding of filamentous fungi for improving cellulase production. Supplementary Information The online version contains supplementary material available at 10.1186/s13068-022-02161-7.
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Affiliation(s)
- Miaoyin Dong
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd, Lanzhou, 730000, Gansu, People's Republic of China.,University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049, People's Republic of China
| | - Shuyang Wang
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd, Lanzhou, 730000, Gansu, People's Republic of China. .,Institute of Biology, Gansu Academy of Sciences, 197 Dingxi South Rd, Lanzhou, 730000, Gansu, People's Republic of China. .,University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049, People's Republic of China.
| | - Fuqiang Xu
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd, Lanzhou, 730000, Gansu, People's Republic of China.,University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049, People's Republic of China
| | - Guoqing Xiao
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd, Lanzhou, 730000, Gansu, People's Republic of China. .,University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049, People's Republic of China.
| | - Jin Bai
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd, Lanzhou, 730000, Gansu, People's Republic of China.,University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049, People's Republic of China
| | - Junkai Wang
- College of Physics and Electronic Engineering, Northwest Normal University, 967Anning East Rd, Lanzhou, 730000, Gansu, People's Republic of China
| | - Xisi Sun
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd, Lanzhou, 730000, Gansu, People's Republic of China.,University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049, People's Republic of China
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22
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Teixeira AP, Stücheli P, Ausländer S, Ausländer D, Schönenberger P, Hürlemann S, Fussenegger M. CelloSelect - A synthetic cellobiose metabolic pathway for selection of stable transgenic CHO cell lines. Metab Eng 2022; 70:23-30. [PMID: 35007751 DOI: 10.1016/j.ymben.2022.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/30/2021] [Accepted: 01/03/2022] [Indexed: 11/30/2022]
Abstract
Current protocols for generating stable transgenic cell lines mostly rely on antibiotic selection or the use of specialized cell lines lacking an essential part of their metabolic machinery, but these approaches require working with either toxic chemicals or knockout cell lines, which can reduce productivity. Since most mammalian cells cannot utilize cellobiose, a disaccharide consisting of two β-1,4-linked glucose molecules, we designed an antibiotic-free selection system, CelloSelect, which consists of a selection cassette encoding Neurospora crassa cellodextrin transporter CDT1 and β-glucosidase GH1-1. When cultivated in glucose-free culture medium containing cellobiose, CelloSelect-transfected cells proliferate by metabolizing cellobiose as a primary energy source, and are protected from glucose starvation. We show that the combination of CelloSelect with a PiggyBac transposase-based integration strategy provides a platform for the swift and efficient generation of stable transgenic cell lines. Growth rate analysis of metabolically engineered cells in cellobiose medium confirmed the expansion of cells stably expressing high levels of a cargo fluorescent marker protein. We further validated this strategy by applying the CelloSelect system for stable integration of sequences encoding two biopharmaceutical proteins, erythropoietin and the monoclonal antibody rituximab, and confirmed that the proteins are efficiently produced in either cellobiose- or glucose-containing medium in suspension-adapted CHO cells cultured in chemically defined media. We believe coupling heterologous metabolic pathways additively to the endogenous metabolism of mammalian cells has the potential to complement or to replace current cell-line selection systems.
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Affiliation(s)
- Ana P Teixeira
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Pascal Stücheli
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Simon Ausländer
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - David Ausländer
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Pascal Schönenberger
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Samuel Hürlemann
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Martin Fussenegger
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, CH-4058, Basel, Switzerland; Faculty of Science, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland.
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23
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Quantifying Oxidation of Cellulose-Associated Glucuronoxylan by Two Lytic Polysaccharide Monooxygenases from Neurospora crassa. Appl Environ Microbiol 2021; 87:e0165221. [PMID: 34613755 PMCID: PMC8612270 DOI: 10.1128/aem.01652-21] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Family AA9 lytic polysaccharide monooxygenases (LPMOs) are abundant in fungi, where they catalyze oxidative depolymerization of recalcitrant plant biomass. These AA9 LPMOs cleave cellulose and some also act on hemicelluloses, primarily other (substituted) β-(1→4)-glucans. Oxidative cleavage of xylan has been shown for only a few AA9 LPMOs, and it remains unclear whether this activity is a minor side reaction or primary function. Here, we show that Neurospora crassa LPMO9F (NcLPMO9F) and the phylogenetically related, hitherto uncharacterized NcLPMO9L from N. crassa are active on both cellulose and cellulose-associated glucuronoxylan but not on glucuronoxylan alone. A newly developed method for simultaneous quantification of xylan-derived and cellulose-derived oxidized products showed that NcLPMO9F preferentially cleaves xylan when acting on a cellulose–beechwood glucuronoxylan mixture, yielding about three times more xylan-derived than cellulose-derived oxidized products. Interestingly, under similar conditions, NcLPMO9L and the previously characterized McLPMO9H, from Malbranchea cinnamomea, showed different xylan-to-cellulose preferences, giving oxidized product ratios of about 0.5:1 and 1:1, respectively, indicative of functional variation among xylan-active LPMOs. Phylogenetic and structural analysis of xylan-active AA9 LPMOs led to the identification of characteristic structural features, including unique features that do not occur in phylogenetically remote AA9 LPMOs, such as four AA9 LPMOs whose lack of activity toward glucuronoxylan was demonstrated in the present study. Taken together, the results provide a path toward discovery of additional xylan-active LPMOs and show that the huge family of AA9 LPMOs has members that preferentially act on xylan. These findings shed new light on the biological role and industrial potential of these fascinating enzymes. IMPORTANCE Plant cell wall polysaccharides are highly resilient to depolymerization by hydrolytic enzymes, partly due to cellulose chains being tightly packed in microfibrils that are covered by hemicelluloses. Lytic polysaccharide monooxygenases (LPMOs) seem well suited to attack these resilient copolymeric structures, but the occurrence and importance of hemicellulolytic activity among LPMOs remain unclear. Here, we show that certain AA9 LPMOs preferentially cleave xylan when acting on a cellulose–glucuronoxylan mixture, and that this ability is the result of protein evolution that has resulted in a clade of AA9 LPMOs with specific structural features. Our findings strengthen the notion that the vast arsenal of AA9 LPMOs in certain fungal species provides functional versatility and that AA9 LPMOs may have evolved to promote oxidative depolymerization of a wide variety of recalcitrant, copolymeric plant polysaccharide structures. These findings have implications for understanding the biological roles and industrial potential of LPMOs.
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24
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Li J, Chen B, Gu S, Zhao Z, Liu Q, Sun T, Zhang Y, Wu T, Liu D, Sun W, Tian C. Coordination of consolidated bioprocessing technology and carbon dioxide fixation to produce malic acid directly from plant biomass in Myceliophthora thermophila. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:186. [PMID: 34556173 PMCID: PMC8461902 DOI: 10.1186/s13068-021-02042-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 09/11/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Consolidated bioprocessing (CBP) technique is a promising strategy for biorefinery construction, producing bulk chemicals directly from plant biomass without extra hydrolysis steps. Fixing and channeling CO2 into carbon metabolism for increased carbon efficiency in producing value-added compounds is another strategy for cost-effective bio-manufacturing. It has not been reported whether these two strategies can be combined in one microbial platform. RESULTS In this study, using the cellulolytic thermophilic fungus Myceliophthora thermophila, we designed and constructed a novel biorefinery system DMCC (Direct microbial conversion of biomass with CO2 fixation) through incorporating two CO2 fixation modules, PYC module and Calvin-Benson-Bassham (CBB) pathway. Harboring the both modules, the average rate of fixing and channeling 13CO2 into malic acid in strain CP51 achieved 44.4, 90.7, and 80.7 mg/L/h, on xylose, glucose, and cellulose, respectively. The corresponding titers of malic acid were up to 42.1, 70.4, and 70.1 g/L, respectively, representing the increases of 40%, 10%, and 7%, respectively, compared to the parental strain possessing only PYC module. The DMCC system was further improved by enhancing the pentose uptake ability. Using raw plant biomass as the feedstock, yield of malic acid produced by the DMCC system was up to 0.53 g/g, with 13C content of 0.44 mol/mol malic acid, suggesting DMCC system can produce 1 t of malic acid from 1.89 t of biomass and fix 0.14 t CO2 accordingly. CONCLUSIONS This study designed and constructed a novel biorefinery system named DMCC, which can convert raw plant biomass and CO2 into organic acid efficiently, presenting a promising strategy for cost-effective production of value-added compounds in biorefinery. The DMCC system is one of great options for realization of carbon neutral economy.
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Affiliation(s)
- Jingen Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Bingchen Chen
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Shuying Gu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Zhen Zhao
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Qian Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Tao Sun
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Yongli Zhang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Taju Wu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Defei Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Wenliang Sun
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Chaoguang Tian
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
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25
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Manavalan T, Stepnov AA, Hegnar OA, Eijsink VGH. Sugar oxidoreductases and LPMOs - two sides of the same polysaccharide degradation story? Carbohydr Res 2021; 505:108350. [PMID: 34049079 DOI: 10.1016/j.carres.2021.108350] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/13/2021] [Accepted: 05/14/2021] [Indexed: 12/20/2022]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) catalyze the oxidative cleavage of glycosidic bonds in recalcitrant polysaccharides such as chitin and cellulose and their discovery has revolutionized our understanding of enzymatic biomass conversion. The discovery of LPMOs raises interesting new questions regarding the roles of other oxidoreductases and abiotic redox processes in biomass conversion. LPMOs need reducing power and an oxygen co-substrate and biomass degrading ecosystems contain a multitude of redox enzymes that affect the availability of both. For example, biomass degrading fungi produce multiple sugar oxidoreductases whose biological functions so far have remained somewhat enigmatic. It is now conceivable that these redox enzymes, in particular H2O2-producing sugar oxidases, could play a role in fueling and controlling LPMO reactions. Here, we shortly review contemporary issues in the LPMO field, paying particular attention to the possible roles of sugar oxidoreductases.
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Affiliation(s)
- Tamilvendan Manavalan
- Faculty of Chemistry, Biotechnology and Food Science, NMBU - Norwegian University of Life Science, N-1432, Ås, Norway
| | - Anton A Stepnov
- Faculty of Chemistry, Biotechnology and Food Science, NMBU - Norwegian University of Life Science, N-1432, Ås, Norway
| | - Olav A Hegnar
- Faculty of Chemistry, Biotechnology and Food Science, NMBU - Norwegian University of Life Science, N-1432, Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, NMBU - Norwegian University of Life Science, N-1432, Ås, Norway.
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26
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The F-box protein gene exo- 1 is a target for reverse engineering enzyme hypersecretion in filamentous fungi. Proc Natl Acad Sci U S A 2021; 118:2025689118. [PMID: 34168079 DOI: 10.1073/pnas.2025689118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Carbohydrate active enzymes (CAZymes) are vital for the lignocellulose-based biorefinery. The development of hypersecreting fungal protein production hosts is therefore a major aim for both academia and industry. However, despite advances in our understanding of their regulation, the number of promising candidate genes for targeted strain engineering remains limited. Here, we resequenced the genome of the classical hypersecreting Neurospora crassa mutant exo-1 and identified the causative point of mutation to reside in the F-box protein-encoding gene, NCU09899. The corresponding deletion strain displayed amylase and invertase activities exceeding those of the carbon catabolite derepressed strain Δcre-1, while glucose repression was still mostly functional in Δexo-1 Surprisingly, RNA sequencing revealed that while plant cell wall degradation genes are broadly misexpressed in Δexo-1, only a small fraction of CAZyme genes and sugar transporters are up-regulated, indicating that EXO-1 affects specific regulatory factors. Aiming to elucidate the underlying mechanism of enzyme hypersecretion, we found the high secretion of amylases and invertase in Δexo-1 to be completely dependent on the transcriptional regulator COL-26. Furthermore, misregulation of COL-26, CRE-1, and cellular carbon and nitrogen metabolism was confirmed by proteomics. Finally, we successfully transferred the hypersecretion trait of the exo-1 disruption by reverse engineering into the industrially deployed fungus Myceliophthora thermophila using CRISPR-Cas9. Our identification of an important F-box protein demonstrates the strength of classical mutants combined with next-generation sequencing to uncover unanticipated candidates for engineering. These data contribute to a more complete understanding of CAZyme regulation and will facilitate targeted engineering of hypersecretion in further organisms of interest.
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27
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Muñoz-Guzmán F, Caballero V, Larrondo LF. A global search for novel transcription factors impacting the Neurospora crassa circadian clock. G3 (BETHESDA, MD.) 2021; 11:jkab100. [PMID: 33792687 PMCID: PMC8495738 DOI: 10.1093/g3journal/jkab100] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 03/16/2021] [Indexed: 01/15/2023]
Abstract
Eukaryotic circadian oscillators share a common circuit architecture, a negative feedback loop in which a positive element activates the transcription of a negative one that then represses the action of the former, inhibiting its own expression. While studies in mammals and insects have revealed additional transcriptional inputs modulating the expression of core clock components, this has been less characterized in the model Neurospora crassa, where the participation of other transcriptional components impacting circadian clock dynamics remains rather unexplored. Thus, we sought to identify additional transcriptional regulators modulating the N. crassa clock, following a reverse genetic screen based on luminescent circadian reporters and a collection of transcription factors (TFs) knockouts, successfully covering close to 60% of them. Besides the canonical core clock components WC-1 and -2, none of the tested transcriptional regulators proved to be essential for rhythmicity. Nevertheless, we identified a set of 23 TFs that when absent lead to discrete, but significant, changes in circadian period. While the current level of analysis does not provide mechanistic information about how these new players modulate circadian parameters, the results of this screen reveal that an important number of light and clock-regulated TFs, involved in a plethora of processes, are capable of modulating the clockworks. This partial reverse genetic clock screen also exemplifies how the N. crassa knockout collection continues to serve as an expedite platform to address broad biological questions.
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Affiliation(s)
- Felipe Muñoz-Guzmán
- ANID—Millennium Science Initiative Program—Millennium Institute for Integrative Biology (iBio), Santiago 8331150, Chile
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Valeria Caballero
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Luis F Larrondo
- ANID—Millennium Science Initiative Program—Millennium Institute for Integrative Biology (iBio), Santiago 8331150, Chile
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
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28
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Wang H, Sun T, Zhao Z, Gu S, Liu Q, Wu T, Wang D, Tian C, Li J. Transcriptional Profiling of Myceliophthora thermophila on Galactose and Metabolic Engineering for Improved Galactose Utilization. Front Microbiol 2021; 12:664011. [PMID: 33995328 PMCID: PMC8113861 DOI: 10.3389/fmicb.2021.664011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/19/2021] [Indexed: 11/13/2022] Open
Abstract
Efficient biological conversion of all sugars from lignocellulosic biomass is necessary for the cost-effective production of biofuels and commodity chemicals. Galactose is one of the most abundant sugar in many hemicelluloses, and it will be important to capture this carbon for an efficient bioconversion process of plant biomass. Thermophilic fungus Myceliophthora thermophila has been used as a cell factory to produce biochemicals directly from renewable polysaccharides. In this study, we draw out the two native galactose utilization pathways, including the Leloir pathway and oxido-reductive pathway, and identify the significance and contribution of them, through transcriptional profiling analysis of M. thermophila and its mutants on galactose. We find that galactokinase was necessary for galactose transporter expression, and disruption of galK resulted in decreased galactose utilization. Through metabolic engineering, both galactokinase deletion and galactose transporter overexpression can activate internal the oxido-reductive pathway and improve the consumption rate of galactose. Finally, the heterologous galactose-degradation pathway, De Ley–Doudoroff (DLD) pathway, was successfully integrated into M. thermophila, and the consumption rate of galactose in the engineered strain was increased by 57%. Our study focuses on metabolic engineering for accelerating galactose utilization in a thermophilic fungus that will be beneficial for the rational design of fungal strains to produce biofuels and biochemicals from a variety of feedstocks with abundant galactose.
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Affiliation(s)
- Hanyu Wang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, China.,Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Tao Sun
- National Technology Innovation Center of Synthetic Biology, Tianjin, China.,Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Zhen Zhao
- National Technology Innovation Center of Synthetic Biology, Tianjin, China.,Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Shuying Gu
- National Technology Innovation Center of Synthetic Biology, Tianjin, China.,Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Qian Liu
- National Technology Innovation Center of Synthetic Biology, Tianjin, China.,Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Taju Wu
- National Technology Innovation Center of Synthetic Biology, Tianjin, China.,Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Depei Wang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Chaoguang Tian
- National Technology Innovation Center of Synthetic Biology, Tianjin, China.,Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Jingen Li
- National Technology Innovation Center of Synthetic Biology, Tianjin, China.,Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
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29
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Ameri AJ, Lewis ZA. Shannon entropy as a metric for conditional gene expression in Neurospora crassa. G3-GENES GENOMES GENETICS 2021; 11:6159613. [PMID: 33751112 PMCID: PMC8049430 DOI: 10.1093/g3journal/jkab055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Accepted: 02/09/2021] [Indexed: 12/04/2022]
Abstract
Neurospora crassa has been an important model organism for molecular biology and genetics for over 60 years. Neurospora crassa has a complex life cycle, with over 28 distinct cell types and is capable of transcriptional responses to many environmental conditions including nutrient availability, temperature, and light. To quantify variation in N. crassa gene expression, we analyzed public expression data from 97 conditions and calculated the Shannon Entropy value for Neurospora’s approximately 11,000 genes. Entropy values can be used to estimate the variability in expression for a single gene over a range of conditions and be used to classify individual genes as constitutive or condition-specific. Shannon entropy has previously been used measure the degree of tissue specificity of multicellular plant or animal genes. We use this metric here to measure variable gene expression in a microbe and provide this information as a resource for the N. crassa research community. Finally, we demonstrate the utility of this approach by using entropy values to identify genes with constitutive expression across a wide range of conditions and to identify genes that are activated exclusively during sexual development.
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Affiliation(s)
- Abigail J Ameri
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Zachary A Lewis
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
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Pang AP, Wang H, Zhang F, Hu X, Wu FG, Zhou Z, Wang W, Lu Z, Lin F. High-dose rapamycin exerts a temporary impact on T. reesei RUT-C30 through gene trFKBP12. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:77. [PMID: 33771193 PMCID: PMC8004424 DOI: 10.1186/s13068-021-01926-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 03/11/2021] [Indexed: 05/15/2023]
Abstract
BACKGROUND Knowledge with respect to regulatory systems for cellulase production is prerequisite for exploitation of such regulatory networks to increase cellulase production, improve fermentation efficiency and reduce the relevant production cost. The target of rapamycin (TOR) signaling pathway is considered as a central signaling hub coordinating eukaryotic cell growth and metabolism with environmental inputs. However, how and to what extent the TOR signaling pathway and rapamycin are involved in cellulase production remain elusive. RESULT At the early fermentation stage, high-dose rapamycin (100 μM) caused a temporary inhibition effect on cellulase production, cell growth and sporulation of Trichoderma reesei RUT-C30 independently of the carbon sources, and specifically caused a tentative morphology defect in RUT-C30 grown on cellulose. On the contrary, the lipid content of T. reesei RUT-C30 was not affected by rapamycin. Accordingly, the transcriptional levels of genes involved in the cellulase production were downregulated notably with the addition of rapamycin. Although the mRNA levels of the putative rapamycin receptor trFKBP12 was upregulated significantly by rapamycin, gene trTOR (the downstream effector of the rapamycin-FKBP12 complex) and genes associated with the TOR signaling pathways were not changed markedly. With the deletion of gene trFKBP12, there is no impact of rapamycin on cellulase production, indicating that trFKBP12 mediates the observed temporary inhibition effect of rapamycin. CONCLUSION Our study shows for the first time that only high-concentration rapamycin induced a transient impact on T. reesei RUT-C30 at its early cultivation stage, demonstrating T. reesei RUT-C30 is highly resistant to rapamycin, probably due to that trTOR and its related signaling pathways were not that sensitive to rapamycin. This temporary influence of rapamycin was facilitated by gene trFKBP12. These findings add to our knowledge on the roles of rapamycin and the TOR signaling pathways play in T. reesei.
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Affiliation(s)
- Ai-Ping Pang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Haiyan Wang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Funing Zhang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Xin Hu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Fu-Gen Wu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Zhihua Zhou
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Wei Wang
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Zuhong Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Fengming Lin
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
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Jagadeeswaran G, Veale L, Mort AJ. Do Lytic Polysaccharide Monooxygenases Aid in Plant Pathogenesis and Herbivory? TRENDS IN PLANT SCIENCE 2021; 26:142-155. [PMID: 33097402 DOI: 10.1016/j.tplants.2020.09.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 09/07/2020] [Accepted: 09/25/2020] [Indexed: 06/11/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs), copper-dependent enzymes mainly found in fungi, bacteria, and viruses, are responsible for enabling plant infection and degradation processes. Since their discovery 10 years ago, significant progress has been made in understanding the major role these enzymes play in biomass conversion. The recent discovery of additional LPMO families in fungi and oomycetes (AA16) as well as insects (AA15) strongly suggests that LPMOs might also be involved in biological processes such as overcoming plant defenses. In this review, we aim to give a comprehensive overview of the potential role of different LPMO families from the perspective of plant defense and their multiple implications in devising new strategies for achieving crop protection from plant pathogens and insect pests.
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Affiliation(s)
- Guru Jagadeeswaran
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Lawrie Veale
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Andrew J Mort
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA.
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Fungal Zn(II) 2Cys 6 Transcription Factor ADS-1 Regulates Drug Efflux and Ergosterol Metabolism under Antifungal Azole Stress. Antimicrob Agents Chemother 2021; 65:AAC.01316-20. [PMID: 33199382 DOI: 10.1128/aac.01316-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 10/07/2020] [Indexed: 11/20/2022] Open
Abstract
Antifungal azoles are the most widely used antifungal drugs in clinical and agricultural practice. Fungi can mount adaptive responses to azole stress by modifying the transcript levels of many genes, and the responsive mechanisms to azoles are the basis for fungi to develop azole resistance. In this study, we identified a new Zn(II)2Cys6 transcription factor, ADS-1, with a positive regulatory function in transcriptional responses to azole stress in the model filamentous fungal species Neurospora crassa Under ketoconazole (KTC) stress, the ads-1 transcript level was significantly increased in N. crassa Deletion of ads-1 increased susceptibility to different azoles, while its overexpression increased resistance to these azoles. The cdr4 gene, which encodes the key azole efflux pump, was positively regulated by ADS-1. Deletion of ads-1 reduced the transcriptional response by cdr4 to KTC stress and increased cellular KTC accumulation under KTC stress, while ads-1 overexpression had the opposite effect. ADS-1 also positively regulated the transcriptional response by erg11, which encodes the azole target lanosterol 14α-demethylase for ergosterol biosynthesis, to KTC stress. After KTC treatment, the ads-1 deletion mutant had less ergosterol but accumulated more lanosterol than the wild type, while ads-1 overexpression had the opposite effect. Homologs of ADS-1 are widely present in filamentous fungal species of Ascomycota but not in yeasts. Deletion of the gene encoding an ADS-1 homolog in Aspergillus flavus also increased susceptibility to KTC and itraconazole (ITZ). Besides, deletion of A. flavus ads-1 (Afads-1) significantly reduced the transcriptional responses by genes encoding homologs of CDR4 and ERG11 in A. flavus to KTC stress, and the deletion mutant accumulated more KTC but less ergosterol. Taken together, these findings demonstrate that the function and regulatory mechanism of ADS-1 homologs among different fungal species in azole responses and the basal resistance of azoles are highly conserved.
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Wang R, Arioka M. Functional analyses of xylanolytic enzymes involved in xylan degradation and utilization in Neurospora crassa. Int J Biol Macromol 2020; 169:302-310. [PMID: 33333093 DOI: 10.1016/j.ijbiomac.2020.12.079] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/10/2020] [Accepted: 12/10/2020] [Indexed: 11/25/2022]
Abstract
Neurospora crassa possesses six putative xylanases and four putative xylosidases. qRT-PCR results showed that the expression of all these xylanolytic enzymes was induced by xylan. Except for two intracellular β-xylosidases, others were shown to be secreted enzymes based on the localization analysis of EGFP-fusion proteins. Among them, GH10-1, GH10-2, GH11-1, and GH11-2 were successfully expressed and characterized as typical endo-β-1,4-xylanases that hydrolyze the xylooligosaccharides with a polymeric degree not less than three or four. Strains deleted for either gh10-1, gh10-2, gh3-7, or gh3-8 displayed decreased growth in xylan and biomass media. Disruption of gh3-7 or gh43-1 resulted in enhanced-xylanolytic enzyme activity when cultivated in biomass medium. Collectively, these results suggest that xylooligosaccharides released by the actions of xylanases and xylosidases not only serve as the carbon sources to maintain the growth of N. crassa, but they also act as inducers to trigger the expression of hydrolytic enzymes in vivo.
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Affiliation(s)
- Ruijie Wang
- Department of Biotechnology, The University of Tokyo, Japan
| | - Manabu Arioka
- Department of Biotechnology, The University of Tokyo, Japan; Collaborative Research Institute for Innovative Microbiology (CRIIM), The University of Tokyo, Japan.
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Abstract
Filamentous fungi are critical for the recycling of plant litter in the biosphere by degrading lignocellulosic biomass into simpler compounds for metabolism. Both saprophytic and pathogenic fungi utilize plant cell wall-degrading enzymes to liberate carbon for metabolism. Several studies have demonstrated a role for cellulase enzymes during infection of economically relevant crops by fungal pathogens. Especially in developing countries, severe plant disease means loss of entire crops, sometimes leading to starvation. In this study, we demonstrate that G-protein signaling is a key component of cellulase production. Therefore, understanding the role of G-protein signaling in the regulation of the unique metabolism of cellulose by these organisms can inform innovations in strain engineering of industrially relevant species for biofuel production and in combatting food shortages caused by plant pathogens. The filamentous fungus Neurospora crassa decomposes lignocellulosic biomass to generate soluble sugars as carbon sources. In this study, we investigated a role for heterotrimeric G-protein signaling in cellulose degradation. Loss of the Gα subunit genes gna-1 and gna-3, the Gβ subunit genes gnb-1 and cpc-2, the Gγ gene gng-1, or the gene for downstream effector adenylyl cyclase (cr-1) resulted in loss of detectable cellulase activity. This defect was also observed in strains expressing a constitutively active version of gna-3 (gna-3Q208L). We found that GNA-1 levels are greatly reduced in Δgna-3, Δgnb-1, and Δgng-1 strains, likely contributing to cellulase defects in these genetic backgrounds. The observation that gna-3Q208L Δgnb-1 strains exhibit cellulase activity, despite greatly reduced levels of GNA-1 protein, is consistent with positive control of cellulase production by GNA-3 that is manifested in the absence of gnb-1. Expression patterns for five cellulase genes showed that Δgna-1, Δgnb-1, and Δgna-3 mutants produce less cellulase mRNA than the wild type, consistent with transcriptional regulation. Δcpc-2 mutants had wild-type levels of cellulase transcripts, suggesting posttranscriptional control. In contrast, results for Δcr-1 mutants support both transcriptional and posttranscriptional control of cellulase activity by cAMP signaling. Cellulase activity defects in Δgna-3 mutants were fully remediated by cAMP supplementation, consistent with GNA-3 operating upstream of cAMP signaling. In contrast, cAMP addition only partially corrected cellulase activity defects in Δgna-1 and Δgnb-1 mutants, suggesting participation of GNA-1 and GNB-1 in additional cAMP-independent pathways that control cellulase activity.
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Hinterdobler W, Beier S, Monroy AA, Berger H, Dattenböck C, Schmoll M. The G-protein Coupled Receptor GPR8 Regulates Secondary Metabolism in Trichoderma reesei. Front Bioeng Biotechnol 2020; 8:558996. [PMID: 33251193 PMCID: PMC7676458 DOI: 10.3389/fbioe.2020.558996] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 10/15/2020] [Indexed: 11/17/2022] Open
Abstract
Changing environmental conditions are of utmost importance for regulation of secondary metabolism in fungi. Different environmental cues including the carbon source, light and the presence of a mating partner can lead to altered production of compounds. Thereby, the heterotrimeric G-protein pathway is of major importance for sensing and adjustment of gene regulation. Regulation of secondary metabolism is crucial in the biotechnological workhorse Trichoderma reesei for knowledge-based adjustment in industrial fermentations, but also with respect to the potential use as a host for heterologous compound production. We investigated the function of the class VII G-protein coupled receptor (GPCR) gene gpr8 that is localized in the vicinity of the SOR cluster, which is responsible for biosynthesis of sorbicillinoids. GPR8 positively impacts regulation of the genes in this cluster in darkness. Accordingly, abundance of trichodimerol and dihydrotrichotetronine as well as other secondary metabolites is decreased in the deletion mutant. Transcriptome analysis moreover showed the major role of GPR8 being exerted in darkness with a considerable influence on regulation of secondary metabolism. Genes regulated in Δgpr8 overlap with those regulated directly or indirectly by the transcription factor YPR2, especially concerning genes related to secondary metabolism. The predicted FAD/FMN containing dehydrogenase gene sor7, one of the positive targets of the cascade triggered by GPR8, has a positive effect on secondary metabolite production, but also cellulase gene expression. Hence SOR7 has some overlapping, but also additional functions compared to GPR8. The G-protein coupled receptor GPR8 exerts a light dependent impact on secondary metabolism, which is in part mediated by the transcription factor YPR2 and the function of SOR7. Hence, T. reesei may apply GPR8 to adjust production of secondary metabolites and hence chemical communication to signals from the environment.
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Affiliation(s)
- Wolfgang Hinterdobler
- Center for Health & Bioresources, Bioresources, AIT Austrian Institute of Technology, Tulln, Austria
| | - Sabrina Beier
- Center for Health & Bioresources, Bioresources, AIT Austrian Institute of Technology, Tulln, Austria
| | - Alberto Alonso Monroy
- Center for Health & Bioresources, Bioresources, AIT Austrian Institute of Technology, Tulln, Austria
| | | | - Christoph Dattenböck
- Center for Health & Bioresources, Bioresources, AIT Austrian Institute of Technology, Tulln, Austria
| | - Monika Schmoll
- Center for Health & Bioresources, Bioresources, AIT Austrian Institute of Technology, Tulln, Austria
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Larsson ED, Dong G, Veryazov V, Ryde U, Hedegård ED. Is density functional theory accurate for lytic polysaccharide monooxygenase enzymes? Dalton Trans 2020; 49:1501-1512. [PMID: 31922155 DOI: 10.1039/c9dt04486h] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The lytic polysaccharide monooxygenase (LPMO) enzymes boost polysaccharide depolymerization through oxidative chemistry, which has fueled the hope for more energy-efficient production of biofuel. We have recently proposed a mechanism for the oxidation of the polysaccharide substrate (E. D. Hedegård and U. Ryde, Chem. Sci., 2018, 9, 3866-3880). In this mechanism, intermediates with superoxide, oxyl, as well as hydroxyl (i.e. [CuO2]+, [CuO]+ and [CuOH]2+) cores were involved. These complexes can have both singlet and triplet spin states, and both spin-states may be important for how LPMOs function during catalytic turnover. Previous calculations on LPMOs have exclusively been based on density functional theory (DFT). However, different DFT functionals are known to display large differences for spin-state splittings in transition-metal complexes, and this has also been an issue for LPMOs. In this paper, we study the accuracy of DFT for spin-state splittings in superoxide, oxyl, and hydroxyl intermediates involved in LPMO turnover. As reference we employ multiconfigurational perturbation theory (CASPT2).
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Affiliation(s)
- Ernst D Larsson
- Department of Theoretical Chemistry, Lund University, Chemical Centre, P. O. Box 124, SE-221 00 Lund, Sweden.
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Ren M, Wang Y, Liu G, Zuo B, Zhang Y, Wang Y, Liu W, Liu X, Zhong Y. The effects of deletion of cellobiohydrolase genes on carbon source-dependent growth and enzymatic lignocellulose hydrolysis in Trichoderma reesei. J Microbiol 2020; 58:687-695. [PMID: 32524344 DOI: 10.1007/s12275-020-9630-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 04/22/2020] [Accepted: 05/04/2020] [Indexed: 10/24/2022]
Abstract
The saprophytic fungus Trichoderma reesei has long been used as a model to study microbial degradation of lignocellulosic biomass. The major cellulolytic enzymes of T. reesei are the cellobiohydrolases CBH1 and CBH2, which constitute more than 70% of total proteins secreted by the fungus. However, their physiological functions and effects on enzymatic hydrolysis of cellulose substrates are not sufficiently elucidated. Here, the cellobiohydrolase-encoding genes cbh1 and cbh2 were deleted, individually or combinatively, by using an auxotrophic marker-recycling technique in T. reesei. When cultured on media with different soluble carbon sources, all three deletion strains (Δcbh1, Δcbh2, and Δcbh1Δcbh2) exhibited no dramatic variation in morphological phenotypes, but their growth rates increased apparently when cultured on soluble cellulase-inducing carbon sources. In addition, Δcbh1 showed dramatically reduced growth and Δcbh1Δcbh2 could hardly grew on microcrystalline cellulose (MCC), whereas all strains grew equally on sodium carboxymethyl cellulose (CMC-Na), suggesting that the influence of the CBHs on growth was carbon source-dependent. Moreover, five representative cellulose substrates were used to analyse the influence of the absence of CBHs on saccharification efficiency. CBH1 deficiency significantly affected the enzymatic hydrolysis rates of various cellulose substrates, where acid pre-treated corn stover (PCS) was influenced the least. CBH2 deficiency reduced the hydrolysis of MCC, PCS, and acid pre-treated and delignified corncob but improved the hydrolysis ability of filter paper. These results demonstrate the specific contributions of CBHs to the hydrolysis of different types of biomass, which could facilitate the development of tailor-made strains with highly efficient hydrolysis enzymes for certain biomass types in the biofuel industry.
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Affiliation(s)
- Meibin Ren
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, P. R. China
| | - Yifan Wang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, P. R. China
| | - Guoxin Liu
- Zibo Center Hospital, Zi Bo, 255036, P. R. China
| | - Bin Zuo
- Leling Shengli New Energy Co., Ltd., Leling, 253600, P. R. China
| | - Yuancheng Zhang
- Leling Shengli New Energy Co., Ltd., Leling, 253600, P. R. China
| | - Yunhe Wang
- Leling Shengli New Energy Co., Ltd., Leling, 253600, P. R. China
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, P. R. China
| | - Xiangmei Liu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, P. R. China.
| | - Yaohua Zhong
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, P. R. China.
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Jiang X, Du J, He R, Zhang Z, Qi F, Huang J, Qin L. Improved Production of Majority Cellulases in Trichoderma reesei by Integration of cbh1 Gene From Chaetomium thermophilum. Front Microbiol 2020; 11:1633. [PMID: 32765463 PMCID: PMC7381231 DOI: 10.3389/fmicb.2020.01633] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 06/23/2020] [Indexed: 11/17/2022] Open
Abstract
Lignocellulose is an abundant waste resource and has been considered as a promising material for production of biofuels or other valuable bio-products. Currently, one of the major bottlenecks in the economic utilization of lignocellulosic materials is the cost-efficiency of converting lignocellulose into soluble sugars for fermentation. One way to address this problem is to seek superior lignocellulose degradation enzymes or further improve current production yields of lignocellulases. In the present study, the lignocellulose degradation capacity of a thermophilic fungus Chaetomium thermophilum was firstly evaluated and compared to that of the biotechnological workhorse Trichoderma reesei. The data demonstrated that compared to T. reesei, C. thermophilum displayed substantially higher cellulose-utilizing efficiency with relatively lower production of cellulases, indicating that better cellulases might exist in C. thermophilum. Comparison of the protein secretome between C. thermophilum and T. reesei showed that the secreted protein categories were quite different in these two species. In addition, to prove that cellulases in C. thermophilum had better enzymatic properties, the major cellulase cellobiohydrolase I (CBH1) from C. thermophilum and T. reesei were firstly characterized, respectively. The data showed that the specific activity of C. thermophilum CBH1 was about 4.5-fold higher than T. reesei CBH1 in a wide range of temperatures and pH. To explore whether increasing CBH1 activity in T. reesei could contribute to improving the overall cellulose-utilizing efficiency of T. reesei, T. reesei cbh1 gene was replaced with C. thermophilum cbh1 gene by integration of C. thermophilum cbh1 gene into T. reesei cbh1 gene locus. The data surprisingly showed that this gene replacement not only increased the cellobiohydrolase activities by around 4.1-fold, but also resulted in stronger induction of other cellulases genes, which caused the filter paper activities, Azo-CMC activities and β-glucosidase activities increased by about 2.2, 1.9, and 2.3-fold, respectively. The study here not only provided new resources of superior cellulases genes and new strategy to improve the cellulase production in T. reesei, but also contribute to opening the path for fundamental research on C. thermophilum.
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Affiliation(s)
- Xianzhang Jiang
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Jiawen Du
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Ruonan He
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Zhengying Zhang
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Feng Qi
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Jianzhong Huang
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Lina Qin
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China.,Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, College of Life Sciences, Fujian Normal University, Fuzhou, China
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Díaz RD, Larrondo LF. A circadian clock in Neurospora crassa functions during plant cell wall deconstruction. Fungal Biol 2020; 124:501-508. [PMID: 32389313 DOI: 10.1016/j.funbio.2020.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 03/05/2020] [Accepted: 03/07/2020] [Indexed: 01/24/2023]
Abstract
Circadian clocks are autonomous timers that are believed to confer organisms a selective advantage by enabling processes to occur at appropriate times of the day. In the model fungus Neurospora crassa, 20-40 % of its genes are reported to be under circadian regulation, as assayed in simple sugar media. Although it has been well-described that Neurospora efficiently deconstructs plant cell wall components, little is known regarding the status of the clock when Neurospora grows on cellulosic material, or whether such a clock has an impact on any of the genes involved in this process. Through luciferase-based reporters and fluorescent detection assays, we show that a clock is functioning when Neurospora grows on cellulose-containing wheat straw as the only carbon and nitrogen source. Additionally, we found that the major cellobiohydrolase encoding gene involved in plant cell wall deconstruction, cbh-1, is rhythmically regulated by the Neurospora clock, in a manner that depends on cellulose concentration and on the transcription factor CRE-1, known as a key player in carbon-catabolite repression in this fungus. Our findings are a step towards a more comprehensive understanding on how clock regulation modulates cellulose degradation, and thus Neurospora's physiology.
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Affiliation(s)
- Rodrigo D Díaz
- Millennium Institute for Integrative Biology, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
| | - Luis F Larrondo
- Millennium Institute for Integrative Biology, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile.
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40
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Arredondo-Santoyo M, Herrera-Camacho J, Vázquez-Garcidueñas MS, Vázquez-Marrufo G. Corn stover induces extracellular laccase activity in Didymosphaeria sp. (syn. = Paraconiothyrium sp.) and exhibits increased in vitro ruminal digestibility when treated with this fungal species. Folia Microbiol (Praha) 2020; 65:849-861. [DOI: 10.1007/s12223-020-00795-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 04/27/2020] [Indexed: 11/28/2022]
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van Munster JM, Daly P, Blythe MJ, Ibbett R, Kokolski M, Gaddipati S, Lindquist E, Singan VR, Barry KW, Lipzen A, Ngan CY, Petzold CJ, Chan LJG, Arvas M, Raulo R, Pullan ST, Delmas S, Grigoriev IV, Tucker GA, Simmons BA, Archer DB. Succession of physiological stages hallmarks the transcriptomic response of the fungus Aspergillus niger to lignocellulose. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:69. [PMID: 32313551 PMCID: PMC7155255 DOI: 10.1186/s13068-020-01702-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 03/24/2020] [Indexed: 05/04/2023]
Abstract
BACKGROUND Understanding how fungi degrade lignocellulose is a cornerstone of improving renewables-based biotechnology, in particular for the production of hydrolytic enzymes. Considerable progress has been made in investigating fungal degradation during time-points where CAZyme expression peaks. However, a robust understanding of the fungal survival strategies over its life time on lignocellulose is thereby missed. Here we aimed to uncover the physiological responses of the biotechnological workhorse and enzyme producer Aspergillus niger over its life time to six substrates important for biofuel production. RESULTS We analysed the response of A. niger to the feedstock Miscanthus and compared it with our previous study on wheat straw, alone or in combination with hydrothermal or ionic liquid feedstock pretreatments. Conserved (substrate-independent) metabolic responses as well as those affected by pretreatment and feedstock were identified via multivariate analysis of genome-wide transcriptomics combined with targeted transcript and protein analyses and mapping to a metabolic model. Initial exposure to all substrates increased fatty acid beta-oxidation and lipid metabolism transcripts. In a strain carrying a deletion of the ortholog of the Aspergillus nidulans fatty acid beta-oxidation transcriptional regulator farA, there was a reduction in expression of selected lignocellulose degradative CAZyme-encoding genes suggesting that beta-oxidation contributes to adaptation to lignocellulose. Mannan degradation expression was wheat straw feedstock-dependent and pectin degradation was higher on the untreated substrates. In the later life stages, known and novel secondary metabolite gene clusters were activated, which are of high interest due to their potential to synthesize bioactive compounds. CONCLUSION In this study, which includes the first transcriptional response of Aspergilli to Miscanthus, we highlighted that life time as well as substrate composition and structure (via variations in pretreatment and feedstock) influence the fungal responses to lignocellulose. We also demonstrated that the fungal response contains physiological stages that are conserved across substrates and are typically found outside of the conditions with high CAZyme expression, as exemplified by the stages that are dominated by lipid and secondary metabolism.
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Affiliation(s)
- Jolanda M. van Munster
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
- Manchester Institute of Biotechnology (MIB) & School of Chemistry, The University of Manchester, Manchester, M1 7DN UK
| | - Paul Daly
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
- Present Address: Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, People’s Republic of China
| | - Martin J. Blythe
- Deep Seq, Faculty of Medicine and Health Sciences, Queen’s Medical Centre, University of Nottingham, Nottingham, NG7 2UH UK
| | - Roger Ibbett
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | - Matt Kokolski
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| | - Sanyasi Gaddipati
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | - Erika Lindquist
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94598 USA
| | - Vasanth R. Singan
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94598 USA
| | - Kerrie W. Barry
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94598 USA
| | - Anna Lipzen
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94598 USA
| | - Chew Yee Ngan
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94598 USA
| | | | | | - Mikko Arvas
- VTT Technical Research Centre of Finland, Tietotie 2, P.O. Box FI-1000, 02044 VTT Espoo, Finland
| | - Roxane Raulo
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| | - Steven T. Pullan
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
- Present Address: Public Health England, National Infection Service, Salisbury, UK
| | - Stéphane Delmas
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
- Present Address: Laboratory of Computational and Quantitative Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, 75005 Paris, France
| | - Igor V. Grigoriev
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94598 USA
| | - Gregory A. Tucker
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | | | - David B. Archer
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
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Zhang R. Functional characterization of cellulose-degrading AA9 lytic polysaccharide monooxygenases and their potential exploitation. Appl Microbiol Biotechnol 2020; 104:3229-3243. [PMID: 32076777 DOI: 10.1007/s00253-020-10467-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 12/25/2019] [Accepted: 02/12/2020] [Indexed: 01/05/2023]
Abstract
Cellulose-degrading auxiliary activity family 9 (AA9) lytic polysaccharide monooxygenases (LPMOs) are known to be widely distributed among filamentous fungi and participate in the degradation of lignocellulose via the oxidative cleavage of celluloses, cello-oligosaccharides, or hemicelluloses. AA9 LPMOs have been reported to have extensive interactions with not only cellulases but also oxidases. The addition of AA9 LPMOs can greatly reduce the amount of cellulase needed for saccharification and increase the yield of glucose. The discovery of AA9 LPMOs has greatly changed our understanding of how fungi degrade cellulose. In this review, apart from summarizing the recent discoveries related to their catalytic reaction, functional diversity, and practical applications, the stability, expression system, and protein engineering of AA9 LPMOs are reviewed for the first time. This review may provide a reference value to further broaden the substrate range of AA9 LPMOs, expand the scope of their practical applications, and realize their customization for industrial utilization.Key Points• The stability and expression system of AA9 LPMOs are reviewed for the first time.• The protein engineering of AA9 LPMOs is systematically summarized for the first time.• The latest research results on the catalytic mechanism of AA9 LPMOs are summarized.• The application of AA9 LPMOs and their relationship with other enzymes are reviewed.
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Affiliation(s)
- Ruiqin Zhang
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao, 266237, China.
- Department of Bioengineering, Huainan Normal University, No. 278 Xueyuannan Road, Huainan, 232038, China.
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43
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Quantitative trait loci (QTL) underlying phenotypic variation in bioethanol-related processes in Neurospora crassa. PLoS One 2020; 15:e0221737. [PMID: 32017762 PMCID: PMC6999864 DOI: 10.1371/journal.pone.0221737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 01/09/2020] [Indexed: 11/19/2022] Open
Abstract
Bioethanol production from lignocellulosic biomass has received increasing attention over the past decade. Many attempts have been made to reduce the cost of bioethanol production by combining the separate steps of the process into a single-step process known as consolidated bioprocessing. This requires identification of organisms that can efficiently decompose lignocellulose to simple sugars and ferment the pentose and hexose sugars liberated to ethanol. There have been many attempts in engineering laboratory strains by adding new genes or modifying genes to expand the capacity of an industrial microorganism. There has been less attention in improving bioethanol-related processes utilizing natural variation existing in the natural ecotypes. In this study, we sought to identify genomic loci contributing to variation in saccharification of cellulose and fermentation of glucose in the fermenting cellulolytic fungus Neurospora crassa through quantitative trait loci (QTL) analysis. We identified one major QTL contributing to fermentation of glucose and multiple putative QTL's underlying saccharification. Understanding the natural variation of the major QTL gene would provide new insights in developing industrial microbes for bioethanol production.
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Li J, Zhang Y, Li J, Sun T, Tian C. Metabolic engineering of the cellulolytic thermophilic fungus Myceliophthora thermophila to produce ethanol from cellobiose. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:23. [PMID: 32021654 PMCID: PMC6995234 DOI: 10.1186/s13068-020-1661-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 01/21/2020] [Indexed: 05/28/2023]
Abstract
BACKGROUND Cellulosic biomass is a promising resource for bioethanol production. However, various sugars in plant biomass hydrolysates including cellodextrins, cellobiose, glucose, xylose, and arabinose, are poorly fermented by microbes. The commonly used ethanol-producing microbe Saccharomyces cerevisiae can usually only utilize glucose, although metabolically engineered strains that utilize xylose have been developed. Direct fermentation of cellobiose could avoid glucose repression during biomass fermentation, but applications of an engineered cellobiose-utilizing S. cerevisiae are still limited because of its long lag phase. Bioethanol production from biomass-derived sugars by a cellulolytic filamentous fungus would have many advantages for the biorefinery industry. RESULTS We selected Myceliophthora thermophila, a cellulolytic thermophilic filamentous fungus for metabolic engineering to produce ethanol from glucose and cellobiose. Ethanol production was increased by 57% from glucose but not cellobiose after introduction of ScADH1 into the wild-type (WT) strain. Further overexpression of a glucose transporter GLT-1 or the cellodextrin transport system (CDT-1/CDT-2) from N. crassa increased ethanol production by 131% from glucose or by 200% from cellobiose, respectively. Transcriptomic analysis of the engineered cellobiose-utilizing strain and WT when grown on cellobiose showed that genes involved in oxidation-reduction reactions and the stress response were downregulated, whereas those involved in protein biosynthesis were upregulated in this effective ethanol production strain. Turning down the expression of pyc gene results the final engineered strain with the ethanol production was further increased by 23%, reaching up to 11.3 g/L on cellobiose. CONCLUSIONS This is the first attempt to engineer the cellulolytic fungus M. thermophila to produce bioethanol from biomass-derived sugars such as glucose and cellobiose. The ethanol production can be improved about 4 times up to 11 grams per liter on cellobiose after a couple of genetic engineering. These results show that M. thermophila is a promising platform for bioethanol production from cellulosic materials in the future.
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Affiliation(s)
- Jinyang Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Yongli Zhang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Jingen Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Tao Sun
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Chaoguang Tian
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
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45
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Gabriel R, Prinz J, Jecmenica M, Romero-Vazquez C, Chou P, Harth S, Floerl L, Curran L, Oostlander A, Matz L, Fritsche S, Gorman J, Schuerg T, Fleißner A, Singer SW. Development of genetic tools for the thermophilic filamentous fungus Thermoascus aurantiacus. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:167. [PMID: 33062053 PMCID: PMC7547499 DOI: 10.1186/s13068-020-01804-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 09/20/2020] [Indexed: 05/04/2023]
Abstract
BACKGROUND Fungal enzymes are vital for industrial biotechnology, including the conversion of plant biomass to biofuels and bio-based chemicals. In recent years, there is increasing interest in using enzymes from thermophilic fungi, which often have higher reaction rates and thermal tolerance compared to currently used fungal enzymes. The thermophilic filamentous fungus Thermoascus aurantiacus produces large amounts of highly thermostable plant cell wall-degrading enzymes. However, no genetic tools have yet been developed for this fungus, which prevents strain engineering efforts. The goal of this study was to develop strain engineering tools such as a transformation system, a CRISPR/Cas9 gene editing system and a sexual crossing protocol to improve the enzyme production. RESULTS Here, we report Agrobacterium tumefaciens-mediated transformation (ATMT) of T. aurantiacus using the hph marker gene, conferring resistance to hygromycin B. The newly developed transformation protocol was optimized and used to integrate an expression cassette of the transcriptional xylanase regulator xlnR, which led to up to 500% increased xylanase activity. Furthermore, a CRISPR/Cas9 gene editing system was established in this fungus, and two different gRNAs were tested to delete the pyrG orthologue with 10% and 35% deletion efficiency, respectively. Lastly, a sexual crossing protocol was established using a hygromycin B- and a 5-fluoroorotic acid-resistant parent strain. Crossing and isolation of progeny on selective media were completed in a week. CONCLUSION The genetic tools developed for T. aurantiacus can now be used individually or in combination to further improve thermostable enzyme production by this fungus.
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Affiliation(s)
- Raphael Gabriel
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608 United States
- Institut für Genetik, Technische Universität Braunschweig, Brunswick, Germany
| | - Julia Prinz
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608 United States
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences Vienna (BOKU), Muthgasse 18, 1190 Vienna, Austria
| | - Marina Jecmenica
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608 United States
- Austrian Centre of Industrial Biotechnology (ACIB), Muthgasse 11, 1190 Vienna, Austria
- Department of Biotechnology, University of Natural Resources and Life Sciences (BOKU), Muthgasse 18, 1190 Vienna, Austria
| | - Carlos Romero-Vazquez
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608 United States
- College of Natural Sciences, University of Puerto-Rico, Rio Pedras, 17 Ave. Universidad STE 1701, San Juan, 00925 Puerto Rico USA
| | - Pallas Chou
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608 United States
- American High School, 36300 Fremont Blvd, Fremont, CA 94536 USA
| | - Simon Harth
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608 United States
- Frankfurt Institute of Molecular Biosciences, Goethe University Frankfurt, 60438 Frankfurt Am Main, Germany
| | - Lena Floerl
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608 United States
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences Vienna (BOKU), Muthgasse 18, 1190 Vienna, Austria
| | - Laure Curran
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608 United States
- École Polytechnique Fédérale de Lausanne, Lausanne, Vaud 1015 Switzerland
| | - Anne Oostlander
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608 United States
- Institut für Genetik, Technische Universität Braunschweig, Brunswick, Germany
| | - Linda Matz
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608 United States
- Institut für Genetik, Technische Universität Braunschweig, Brunswick, Germany
| | - Susanne Fritsche
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608 United States
- Department of Food Science and Technology, University of Natural Resources and Life Sciences Vienna (BOKU), Muthgasse 18, 1190 Vienna, Austria
| | - Jennifer Gorman
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608 United States
| | - Timo Schuerg
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608 United States
| | - André Fleißner
- Institut für Genetik, Technische Universität Braunschweig, Brunswick, Germany
| | - Steven W. Singer
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608 United States
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Lin L, Wang S, Li X, He Q, Benz JP, Tian C. STK-12 acts as a transcriptional brake to control the expression of cellulase-encoding genes in Neurospora crassa. PLoS Genet 2019; 15:e1008510. [PMID: 31765390 PMCID: PMC6901240 DOI: 10.1371/journal.pgen.1008510] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 12/09/2019] [Accepted: 11/05/2019] [Indexed: 12/21/2022] Open
Abstract
Cellulolytic fungi have evolved a complex regulatory network to maintain the precise balance of nutrients required for growth and hydrolytic enzyme production. When fungi are exposed to cellulose, the transcript levels of cellulase genes rapidly increase and then decline. However, the mechanisms underlying this bell-shaped expression pattern are unclear. We systematically screened a protein kinase deletion set in the filamentous fungus Neurospora crassa to search for mutants exhibiting aberrant expression patterns of cellulase genes. We observed that the loss of stk-12 (NCU07378) caused a dramatic increase in cellulase production and an extended period of high transcript abundance of major cellulase genes. These results suggested that stk-12 plays a critical role as a brake to turn down the transcription of cellulase genes to repress the overexpression of hydrolytic enzymes and prevent energy wastage. Transcriptional profiling analyses revealed that cellulase gene expression levels were maintained at high levels for 56 h in the Δstk-12 mutant, compared to only 8 h in the wild-type (WT) strain. After growth on cellulose for 3 days, the transcript levels of cellulase genes in the Δstk-12 mutant were 3.3-fold over WT, and clr-2 (encoding a transcriptional activator) was up-regulated in Δstk-12 while res-1 and rca-1 (encoding two cellulase repressors) were down-regulated. Consequently, total cellulase production in the Δstk-12 mutant was 7-fold higher than in the WT. These results strongly suggest that stk-12 deletion results in dysregulation of the cellulase expression machinery. Further analyses showed that STK-12 directly targets IGO-1 to regulate cellulase production. The TORC1 pathway promoted cellulase production, at least partly, by inhibiting STK-12 function, and STK-12 and CRE-1 functioned in parallel pathways to repress cellulase gene expression. Our results clarify how cellulase genes are repressed at the transcriptional level during cellulose induction, and highlight a new strategy to improve industrial fungal strains.
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Affiliation(s)
- Liangcai Lin
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Shanshan Wang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Xiaolin Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Qun He
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - J. Philipp Benz
- Technical University of Munich, TUM School of Life Sciences Weihenstephan, Hans-Carl-von-Carlowitz-Platz, Freising, Germany
- Technical University of Munich, Institute for Advanced Study, Lichtenbergstr, Garching, Germany
| | - Chaoguang Tian
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
- * E-mail:
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47
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Li Y, Hu Y, Zhao K, Pan Y, Qu Y, Zhao J, Qin Y. The Indispensable Role of Histone Methyltransferase PoDot1 in Extracellular Glycoside Hydrolase Biosynthesis of Penicillium oxalicum. Front Microbiol 2019; 10:2566. [PMID: 31787956 PMCID: PMC6853848 DOI: 10.3389/fmicb.2019.02566] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 10/23/2019] [Indexed: 11/13/2022] Open
Abstract
Histone methylation is associated with transcription regulation, but its role for glycoside hydrolase (GH) biosynthesis is still poorly understood. We identified the histone H3 lysine 79 (H3K79)-specific methyltransferase PoDot1 in Penicillium oxalicum. PoDot1 affects conidiation by regulating the transcription of key regulators (BrlA, FlbC, and StuA) of asexual development and is required in normal hyphae septum and branch formation by regulating the transcription of five septin-encoding genes, namely, aspA, aspB, aspC, aspD, and aspE. Tandem affinity purification/mass spectrometry showed that PoDot1 has no direct interaction with transcription machinery, but it affects the expressions of extracellular GH genes extensively. The expression of genes (amy15A, amy13A, cel7A/cbh1, cel61A, chi18A, cel3A/bgl1, xyn10A, cel7B/eg1, cel5B/eg2, and cel6A/cbh2) that encode the top 10 GHs was remarkably downregulated by Podot1 deletion (ΔPodot1). Consistent with the decrease in gene transcription level, the activities of amylases and cellulases were significantly decreased in ΔPodot1 mutants in agar (solid) and fermentation (liquid) media. The repression of GH gene expressions caused by PoDot1 deletion was not mediated by key transcription factors, such as AmyR, ClrB, CreA, and XlnR, but was accompanied by defects in global demethylated H3K79 (H3K79me2) and trimethylated H3K79 (H3K79me3). The impairment of H3K79me2 on specific GH gene loci was observed due to PoDot1 deletion. The results implies that defects of H3K79 methylation is the key reason of the downregulated transcription level of GH-encoding genes and reveals the indispensable role of PoDot1 in extracellular GH biosynthesis.
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Affiliation(s)
- Yanan Li
- National Glycoengineering Research Center and State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.,College of Life Sciences, Henan Agricultural University, Zhengzhou, China.,Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao, China
| | - Yueyan Hu
- National Glycoengineering Research Center and State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.,Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao, China
| | - Kaili Zhao
- National Glycoengineering Research Center and State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.,Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao, China
| | - Yunjun Pan
- National Glycoengineering Research Center and State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yinbo Qu
- National Glycoengineering Research Center and State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.,Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao, China
| | - Jian Zhao
- National Glycoengineering Research Center and State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yuqi Qin
- National Glycoengineering Research Center and State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.,Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao, China
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48
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Horta MAC, Thieme N, Gao Y, Burnum-Johnson KE, Nicora CD, Gritsenko MA, Lipton MS, Mohanraj K, de Assis LJ, Lin L, Tian C, Braus GH, Borkovich KA, Schmoll M, Larrondo LF, Samal A, Goldman GH, Benz JP. Broad Substrate-Specific Phosphorylation Events Are Associated With the Initial Stage of Plant Cell Wall Recognition in Neurospora crassa. Front Microbiol 2019; 10:2317. [PMID: 31736884 PMCID: PMC6838226 DOI: 10.3389/fmicb.2019.02317] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 09/23/2019] [Indexed: 12/26/2022] Open
Abstract
Fungal plant cell wall degradation processes are governed by complex regulatory mechanisms, allowing the organisms to adapt their metabolic program with high specificity to the available substrates. While the uptake of representative plant cell wall mono- and disaccharides is known to induce specific transcriptional and translational responses, the processes related to early signal reception and transduction remain largely unknown. A fast and reversible way of signal transmission are post-translational protein modifications, such as phosphorylations, which could initiate rapid adaptations of the fungal metabolism to a new condition. To elucidate how changes in the initial substrate recognition phase of Neurospora crassa affect the global phosphorylation pattern, phospho-proteomics was performed after a short (2 min) induction period with several plant cell wall-related mono- and disaccharides. The MS/MS-based peptide analysis revealed large-scale substrate-specific protein phosphorylation and de-phosphorylations. Using the proteins identified by MS/MS, a protein-protein-interaction (PPI) network was constructed. The variance in phosphorylation of a large number of kinases, phosphatases and transcription factors indicate the participation of many known signaling pathways, including circadian responses, two-component regulatory systems, MAP kinases as well as the cAMP-dependent and heterotrimeric G-protein pathways. Adenylate cyclase, a key component of the cAMP pathway, was identified as a potential hub for carbon source-specific differential protein interactions. In addition, four phosphorylated F-Box proteins were identified, two of which, Fbx-19 and Fbx-22, were found to be involved in carbon catabolite repression responses. Overall, these results provide unprecedented and detailed insights into a so far less well known stage of the fungal response to environmental cues and allow to better elucidate the molecular mechanisms of sensory perception and signal transduction during plant cell wall degradation.
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Affiliation(s)
- Maria Augusta C. Horta
- Holzforschung München, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Nils Thieme
- Holzforschung München, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Yuqian Gao
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States
| | | | - Carrie D. Nicora
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States
| | - Marina A. Gritsenko
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States
| | - Mary S. Lipton
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, United States
| | - Karthikeyan Mohanraj
- The Institute of Mathematical Sciences (IMSc), Homi Bhabha National Institute (HBNI), Chennai, India
| | - Leandro José de Assis
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Liangcai Lin
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Chaoguang Tian
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Gerhard H. Braus
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Katherine A. Borkovich
- Department of Microbiology & Plant Pathology, Institute for Integrative Genome Biology, University of California, Riverside, Riverside, CA, United States
| | - Monika Schmoll
- AIT - Austrian Institute of Technology GmbH, Center for Health & Bioresources, Tulln, Austria
| | - Luis F. Larrondo
- Millennium Institute for Integrative Biology (iBio), Departamento Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Areejit Samal
- The Institute of Mathematical Sciences (IMSc), Homi Bhabha National Institute (HBNI), Chennai, India
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
- Institute for Advanced Study, Technical University of Munich, Garching, Germany
| | - J. Philipp Benz
- Holzforschung München, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
- Institute for Advanced Study, Technical University of Munich, Garching, Germany
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49
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Wang F, Zhang R, Han L, Guo W, Du Z, Niu K, Liu Y, Jia C, Fang X. Use of fusion transcription factors to reprogram cellulase transcription and enable efficient cellulase production in Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:244. [PMID: 31636703 PMCID: PMC6792246 DOI: 10.1186/s13068-019-1589-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 10/09/2019] [Indexed: 05/23/2023]
Abstract
BACKGROUND Trichoderma reesei is widely used for cellulase production and accepted as an example for cellulase research. Cre1-mediated carbon catabolite repression (CCR) can significantly inhibit the transcription of cellulase genes during cellulase fermentation in T. reesei. Early efforts have been undertaken to modify Cre1 for the release of CCR; however, this approach leads to arrested hyphal growth and decreased biomass accumulation, which negatively affects cellulase production. RESULTS In this study, novel fusion transcription factors (fTFs) were designed to release or attenuate CCR inhibition in cellulase transcription, while Cre1 was left intact to maintain normal hyphal growth. Four designed fTFs were introduced into the T. reesei genome, which generated several transformants, named Kuace3, Kuclr2, Kuace2, and Kuxyr1. No obvious differences in growth were observed between the parent and transformant strains. However, the transcription levels of cel7a, a major cellulase gene, were significantly elevated in all the transformants, particularly in Kuace2 and Kuxyr1, when grown on lactose as a carbon source. This suggested that CCR inhibition was released or attenuated in the transformant strains. The growth of Kuace2 and Kuxyr1 was approximately equivalent to that of the parent strain in fed-batch fermentation process. However, we observed a 3.2- and 2.1-fold increase in the pNPCase titers of the Kuace2 and Kuxyr1 strains, respectively, compared with that of the parent strain. Moreover, we observed a 6.1- and 3.9-fold increase in the pNPCase titers of the Kuace2 and Kuxyr1 strains, respectively, compared with that of Δcre1 strain. CONCLUSIONS A new strategy based on fTFs was successfully established in T. reesei to improve cellulase titers without impairing fungal growth. This study will be valuable for lignocellulosic biorefining and for guiding the development of engineering strategies for producing other important biochemical compounds in fungal species.
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Affiliation(s)
- Fangzhong Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237 China
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, China
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong China
| | - Ruiqin Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237 China
| | - Lijuan Han
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237 China
| | - Wei Guo
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237 China
| | - Zhiqiang Du
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237 China
| | - Kangle Niu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237 China
| | - Yucui Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237 China
| | - Chunjiang Jia
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong China
| | - Xu Fang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237 China
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Kim HJ, Lee WH, Turner TL, Kwak S, Jin YS. An extra copy of the β-glucosidase gene improved the cellobiose fermentation capability of an engineered Saccharomyces cerevisiae strain. 3 Biotech 2019; 9:367. [PMID: 31588391 DOI: 10.1007/s13205-019-1899-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 09/16/2019] [Indexed: 01/06/2023] Open
Abstract
In a previously engineered Saccharomyces cerevisiae recombinant, the cellobiose fermentation rate was significantly lower than the glucose fermentation rate. Thus, we implemented a genome-wide perturbation library to find gene targets for improving the cellobiose fermentation capability of the yeast strain. Unexpectedly, we discovered a transformant that contained an additional β-glucosidase gene (gh1-1), possibly through homologous recombination between the plasmids. The additional β-glucosidase led to the fastest cellobiose fermentation activity among all the transformants evaluated, and the strain demonstrated significantly higher β-glucosidase activity than the control strain, especially during the initial exponential growth phase. The present work revealed the benefit of the extra gh1-1 copy for efficient cellobiose fermentation in the engineered S. cerevisiae strain.
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Affiliation(s)
- Hyo Jin Kim
- 1Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
- 2Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
- 3Graduate School of International Agricultural Technology, Seoul National University, Pyeongchang, 25354 Republic of Korea
- 4Institutes of Green Bio Science and Technology, Seoul National University, Pyeongchang, 25354 Republic of Korea
| | - Won-Heong Lee
- 1Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
- 2Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
- 5Bioenergy Science and Technology, Chonnam National University, Gwangju, 61186 Korea
| | - Timothy Lee Turner
- 1Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
- 2Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
- 6Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611 USA
| | - Suryang Kwak
- 1Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
- 2Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
| | - Yong-Su Jin
- 1Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
- 2Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
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