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Sharma G, Kaur B, Singh V, Raheja Y, Falco MD, Tsang A, Chadha BS. Genome and secretome insights: unravelling the lignocellulolytic potential of Myceliophthora verrucosa for enhanced hydrolysis of lignocellulosic biomass. Arch Microbiol 2024; 206:236. [PMID: 38676717 DOI: 10.1007/s00203-024-03974-w] [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: 02/22/2024] [Accepted: 04/22/2024] [Indexed: 04/29/2024]
Abstract
Lignocellulolytic enzymes from a novel Myceliophthora verrucosa (5DR) strain was found to potentiate the efficacy of benchmark cellulase during saccharification of acid/alkali treated bagasse by ~ 2.24 fold, indicating it to be an important source of auxiliary enzymes. The De-novo sequencing and analysis of M. verrucosa genome (31.7 Mb) revealed to encode for 7989 putative genes, representing a wide array of CAZymes (366) with a high proportions of auxiliary activity (AA) genes (76). The LC/MS QTOF based secretome analysis of M. verrucosa showed high abundance of glycosyl hydrolases and AA proteins with cellobiose dehydrogenase (CDH) (AA8), being the most prominent auxiliary protein. A gene coding for lytic polysaccharide monooxygenase (LPMO) was expressed in Pichia pastoris and CDH produced by M. verrucosa culture on rice straw based solidified medium were purified and characterized. The mass spectrometry of LPMO catalyzed hydrolytic products of avicel showed the release of both C1/C4 oxidized products, indicating it to be type-3. The lignocellulolytic cocktail comprising of in-house cellulase produced by Aspergillus allahabadii strain spiked with LPMO & CDH exhibited enhanced and better hydrolysis of mild alkali deacetylated (MAD) and unwashed acid pretreated rice straw slurry (UWAP), when compared to Cellic CTec3 at high substrate loading rate.
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Affiliation(s)
- Gaurav Sharma
- Department of Microbiology, Guru Nanak Dev University, Amritsar, Punjab, 143005, India
| | - Baljit Kaur
- Department of Microbiology, Guru Nanak Dev University, Amritsar, Punjab, 143005, India
| | - Varinder Singh
- Department of Microbiology, Guru Nanak Dev University, Amritsar, Punjab, 143005, India
| | - Yashika Raheja
- Department of Microbiology, Guru Nanak Dev University, Amritsar, Punjab, 143005, India
| | - Marcos Di Falco
- Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, QC, H4B 1R6, Canada
| | - Adrian Tsang
- Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, QC, H4B 1R6, Canada
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Li J, Wang Y, Yang K, Wang X, Wang Y, Zhang H, Huang H, Su X, Yao B, Luo H, Qin X. Development of an efficient protein expression system in the thermophilic fungus Myceliophthora thermophila. Microb Cell Fact 2023; 22:236. [PMID: 37974259 PMCID: PMC10652509 DOI: 10.1186/s12934-023-02245-5] [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: 07/07/2023] [Accepted: 11/05/2023] [Indexed: 11/19/2023] Open
Abstract
BACKGROUND Thermophilic fungus Myceliophthora thermophila has been widely used in industrial applications due to its ability to produce various enzymes. However, the lack of an efficient protein expression system has limited its biotechnological applications. RESULTS In this study, using a laccase gene reporting system, we developed an efficient protein expression system in M. thermophila through the selection of strong constitutive promoters, 5'UTRs and signal peptides. The expression of the laccase was confirmed by enzyme activity assays. The results showed that the Mtpdc promoter (Ppdc) was able to drive high-level expression of the target protein in M. thermophila. Manipulation of the 5'UTR also has significant effects on protein expression and secretion. The best 5'UTR (NCA-7d) was identified. The transformant containing the laccase gene under the Mtpdc promoter, NCA-7d 5'UTR and its own signal peptide with the highest laccase activity (1708 U/L) was obtained. In addition, the expression system was stable and could be used for the production of various proteins, including homologous proteins like MtCbh-1, MtGh5-1, MtLPMO9B, and MtEpl1, as well as a glucoamylase from Trichoderma reesei. CONCLUSIONS An efficient protein expression system was established in M. thermophila for the production of various proteins. This study provides a valuable tool for protein production in M. thermophila and expands its potential for biotechnological applications.
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Affiliation(s)
- Jinyang Li
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Yidi Wang
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Kun Yang
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Xiaolu Wang
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Yuan Wang
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Honglian Zhang
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Huoqing Huang
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Xiaoyun Su
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Bin Yao
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Huiying Luo
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China.
| | - Xing Qin
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China.
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Yang J, Zhang X, Sun Q, Li R, Wang X, Zhao G, He X, Zheng F. Modulation of the catalytic activity and thermostability of a thermostable GH7 endoglucanase by engineering the key loop B3. Int J Biol Macromol 2023; 248:125945. [PMID: 37482151 DOI: 10.1016/j.ijbiomac.2023.125945] [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: 05/15/2023] [Revised: 07/18/2023] [Accepted: 07/20/2023] [Indexed: 07/25/2023]
Abstract
The loop B3 of glycoside hydrolase family 7 (GH7) endoglucanases is confined into long and short types. TtCel7 is a thermophilic GH7 endoglucanase from Thermothelomyces thermophilus ATCC 42464 with a long loop B3. TtCel7 was distinct for the excellent thermostability (>30 % residual activity after 1-h incubation at 90 °C). The catalytic efficiency was reduced by removing the disulfide bond in loop B3 (C220A) and truncated the loop B3 (B3cut). However, B3cut exhibited improved thermostability, the remaining enzyme activity increased by 39 %-171 % compared toTtCel7 when treated at 70-90 °C for 1-h. Based on the analysis of molecular dynamics simulation, both loops B1 and A3 of B3cut swing toward the catalytic center, which contributed to the reduced cleft-space and increased structure-rigidity. Conversely, the deletion of disulfide bond resulted in a reduction of structural rigidity in C220A. Through structure-directed enzyme modulation, this study has identified two structural elements that are related to the catalysis and thermostability of TtCel7. The loop B3 of TtCel7 possibly stretches the catalytic pocket, thereby increases the openness of the catalytic tunnel and enhancing flexibility for efficient catalysis. Additionally, the disulfide bond within loop B3 serves to enhance structural stability and maintain a heightened level of activity.
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Affiliation(s)
- Junzhao Yang
- College of Biological Sciences, Beijing Forestry University, Beijing 100083, China
| | - Xinrui Zhang
- College of Biological Sciences, Beijing Forestry University, Beijing 100083, China
| | - Qingyang Sun
- College of Biological Sciences, Beijing Forestry University, Beijing 100083, China
| | - Ruilin Li
- College of Biological Sciences, Beijing Forestry University, Beijing 100083, China
| | - Xiaoyu Wang
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Guozhu Zhao
- College of Biological Sciences, Beijing Forestry University, Beijing 100083, China
| | - Xiangwei He
- College of Biological Sciences, Beijing Forestry University, Beijing 100083, China
| | - Fei Zheng
- College of Biological Sciences, Beijing Forestry University, Beijing 100083, China.
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Gruninger RJ, Tsang A, McAllister TA. Identification of Genes Involved in the Degradation of Lignocellulose Using Comparative Transcriptomics. Methods Mol Biol 2023; 2657:285-304. [PMID: 37149538 DOI: 10.1007/978-1-0716-3151-5_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Lignocellulosic biomass represents an abundant, renewable resource that can be used to produce biofuels, low-cost livestock feed, and high-value chemicals. The potential of this bioresource has led to intensive research efforts to develop cost-effective methods to break down lignocellulose. The efficiency with which the anaerobic fungi (phylum Neocallimastigomycota) degrade plant biomass is well recognized and in recent years has received renewed interest. Transcriptomics has been used to identify enzymes that are expressed by these fungi and are involved in the degradation of a range of lignocellulose feedstocks. The transcriptome is the entire complement of coding and non-coding RNA transcripts that are expressed by a cell under a particular set of conditions. Monitoring changes in gene expression can provide fundamental information about the biology of an organism. Here we outline a general methodology that will enable researchers to conduct comparative transcriptomic studies with the goal of identifying enzymes involved in the degradation of the plant cell wall. The method described will include growth of fungal cultures, isolation and sequencing of RNA, and a basic description of data analysis for bioinformatic identification of differentially expressed transcripts.
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Affiliation(s)
- Robert J Gruninger
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, AB, Canada.
| | - Adrian Tsang
- Centre for Structural and Functional Genomics, Concordia University, Montreal, QC, Canada
| | - Tim A McAllister
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, AB, Canada
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MtTRC-1, a Novel Transcription Factor, Regulates Cellulase Production via Directly Modulating the Genes Expression of the Mthac-1 and Mtcbh-1 in Myceliophthora thermophila. Appl Environ Microbiol 2022; 88:e0126322. [PMID: 36165620 PMCID: PMC9552611 DOI: 10.1128/aem.01263-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
The thermophilic fungus Myceliophthora thermophila has been used to produce industrial enzymes and biobased chemicals. In saprotrophic fungi, the mechanisms regulating cellulase production have been studied, which revealed the involvement of multiple transcription factors. However, in M. thermophila, the transcription factors influencing cellulase gene expression and secretion remain largely unknown. In this study, we identified and characterized a novel cellulase regulator (MtTRC-1) in M. thermophila through a combination of functional genomics and genetic analyses. Deletion of Mttrc-1 resulted in significantly decreased cellulase production and activities. Transcriptome analysis revealed downregulation of not only the encoding genes of main cellulases but also the transcriptional regulator MtHAC-1 of UPR pathway after disruption of MtTRC-1 under cellulolytic induction conditions. Herein, we also characterized the ortholog of the yeast HAC1p in M. thermophila. We show that Mthac-1 mRNA undergoes an endoplasmic reticulum (ER) stress-induced splicing by removing a 23-nucleotide (nt) intron. Notably, the protein secretion on cellulose was dramatically impaired by the deletion of MtHAC-1. Moreover, the colonial growth on various carbon sources was defective in the absence of MtHAC-1. Electrophoretic mobility shift assays and chromatin immunoprecipitation assays verified MtTRC-1 regulates the transcription of Mthac-1 and the major cellulase gene Mtcbh-1 by binding directly to the promoters in vitro and in vivo. Furthermore, DNase I footprinting assays identified the putative consensus binding site (5′-GNG/C-3′). These results revealed the importance of MtTRC-1 for positively regulating cellulase production. This finding has clarified the complex regulatory pathways involved in cellulolytic enzyme production. IMPORTANCE In the present study, we characterized a novel regulator MtTRC-1 in M. thermophila, which regulated cellulase production through direct transcriptional regulation of the Mthac-1 and Mtcbh-1 genes. Our data demonstrated that MtHAC-1 is a key factor for the cellulase secretion capacity of M. thermophila. Our data indicate that this thermophilic fungus regulates cellulase production through a multilevels network, in which the protein secretory pathway is modulated by MtHAC-1-dependent UPR pathway and the cellulase gene expression is directly regulated in parallel by transcription factors. The conservation of Mttrc1 in filamentous fungi suggests this mechanism may be exploited to engineer filamentous fungal cell factories capable of producing proteins on an industrial scale.
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Sharma G, Kaur B, Raheja Y, Agrawal D, Basotra N, Di Falco M, Tsang A, Singh Chadha B. Lignocellulolytic enzymes from Aspergillus allahabadii for efficient bioconversion of rice straw into fermentable sugars and biogas. BIORESOURCE TECHNOLOGY 2022; 360:127507. [PMID: 35753566 DOI: 10.1016/j.biortech.2022.127507] [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: 05/17/2022] [Revised: 06/18/2022] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
The study was aimed at developing lignocellulolytic strain capable of efficient hydrolysis of mild alkali deacetylated (MAD) rice straw. The valorisation of lignin rich black liquor obtained during pre-treatment of rice straw into biogas was also evaluated. Study reports highly proficient cellulolytic Aspergillus allahabadii strain harbouring a spectrum of CAZymes based on comparative genome wide analysis that was subjected to strain breeding for developing a hyper producing strain. The secretome analysis showed up-modulation and several folds increase in the CAZyme activities in the culture extracts of the developed strain MAN 40 when compared to parent. The cellulolytic cocktail of the developed strain showed 1.52 folds higher saccharification of MAD rice straw when compared to Cellic CTec 3. Moreover, in-situ addition of cellulases derived from developed strains resulted in ∼3.7 folds higher methane production during anaerobic digestion of mixture of lignin rich black liquor and differently treated rice straw.
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Affiliation(s)
- Gaurav Sharma
- Department of Microbiology, Guru Nanak Dev University, Amritsar 143005, Punjab, India
| | - Baljit Kaur
- Department of Microbiology, Guru Nanak Dev University, Amritsar 143005, Punjab, India
| | - Yashika Raheja
- Department of Microbiology, Guru Nanak Dev University, Amritsar 143005, Punjab, India
| | - Dhruv Agrawal
- Department of Microbiology, Guru Nanak Dev University, Amritsar 143005, Punjab, India
| | - Neha Basotra
- Department of Microbiology, Guru Nanak Dev University, Amritsar 143005, Punjab, India
| | - Marcos Di Falco
- Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec H4B 1R6, Canada
| | - Adrian Tsang
- Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec H4B 1R6, Canada
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Liu N, Yu W, Guo X, Chen J, Xia D, Yu J, Li D. Oxidative cleavage of cellulose in the horse gut. Microb Cell Fact 2022; 21:38. [PMID: 35279161 PMCID: PMC8917663 DOI: 10.1186/s12934-022-01767-8] [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: 10/28/2021] [Accepted: 03/01/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Lytic polysaccharide monooxygenases (LPMOs) belonging to the auxiliary activity 9 family (AA9) are widely found in aerobic fungi. These enzymes are O2-dependent copper oxidoreductases that catalyze the oxidative cleavage of cellulose. However, studies that have investigated AA9 LPMOs of aerobic fungi in the herbivore gut are scare. To date, whether oxidative cleavage of cellulose occurs in the herbivore gut is unknown.
Results
We report for the first time experimental evidence that AA9 LPMOs from aerobic thermophilic fungi catalyze the oxidative cleavage of cellulose present in the horse gut to C1-oxidized cellulose and C1- and C4-oxidized cello-oligosaccharides. We isolated and identified three thermophilic fungi and measured their growth and AA9 LPMO expression at 37 °C in vitro. We also assessed the expression and the presence of AA9 LPMOs from thermophilic fungi in situ. Finally, we used two recombinant AA9 LPMOs and a native AA9 LPMO from thermophilic fungi to cleave cellulose to yield C1-oxidized products at 37 °C in vitro.
Conclusions
The oxidative cleavage of cellulose occurs in the horse gut. This finding will broaden the known the biological functions of the ubiquitous LPMOs and aid in determining biological significance of aerobic thermophilic fungi.
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Zhao Q, Li H, Guo Z, Gao M. Analysis of microbial diversity in the root of Astragalus mongholicus. BRAZ J BIOL 2022; 82:e261331. [DOI: 10.1590/1519-6984.261331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 07/19/2022] [Indexed: 11/21/2022] Open
Abstract
Abstract The dry root of Astragalus mongholicus has therapeutic effects such as tonifing the middle - jiao, replenishing qi, solidifing the surface, promoting diuresis, dispelling sepsis outwards and nourishing muscle. There are some slices having black spots after slicing the root of astragalus. The diversity of endophytic fungi between slices with black spots and normal slices was analysed in this paper. The endophytic fungal sequences obtained by high-throughput sequencing were 298,044 and 297,396, and the 116 OTU subsets obtained after clustering belonged to 3 phyla, 9 classes, 22 orders, 38 families and 46 genera. The dominant classes were Eurotiomycetes and Leotiomycetes. The dominant order is Eurotiales and Helotiales. The dominant families are Helotiales_fam_Incertae_sedis and Aspergillaceae. The dominant genera are Cadophora and Aspergillus. There are some peculiar fungal flora in both normal slices and spotted slices. The study on endophytic fungi diversity of astragalus slices will provide some help for drug development of this plant.
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Affiliation(s)
- Q. Zhao
- Xianyang Normal University, China
| | - H. Li
- Xianyang Normal University, China
| | - Z. Guo
- Xianyang Normal University, China
| | - M. Gao
- Xianyang Normal University, China
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Yang YJ, Liu Y, Liu DD, Guo WZ, Wang LX, Wang XJ, Lv HX, Yang Y, Liu Q, Tian CG. Development of a flow cytometry-based plating-free system for strain engineering in industrial fungi. Appl Microbiol Biotechnol 2021; 106:713-727. [PMID: 34921331 DOI: 10.1007/s00253-021-11733-w] [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: 10/29/2021] [Revised: 11/29/2021] [Accepted: 12/03/2021] [Indexed: 01/02/2023]
Abstract
Recent technical advances regarding filamentous fungi have accelerated the engineering of fungal-based production and benefited basic science. However, challenges still remain and limit the speed of fungal applications. For example, high-throughput technologies tailored to filamentous fungi are not yet commonly available for genetic modification. The currently used fungal genetic manipulations are time-consuming and laborious. Here, we developed a flow cytometry-based plating-free system to directly screen and isolate the transformed protoplasts in industrial fungi Myceliophthora thermophila and Aspergillus niger. This system combines genetic engineering via the 2A peptide and the CRISPR-Cas9 system, strain screening by flow cytometry, and direct sorting of colonies for deep-well-plate incubation and phenotypic analysis while avoiding culturing transformed protoplasts in plates, colony picking, conidiation, and cultivation. As a proof of concept, we successfully applied this system to generate the glucoamylase-hyperproducing strains MtYM6 and AnLM3 in M. thermophila and A. niger, respectively. Notably, the protein secretion level and enzyme activities in MtYM6 were 17.3- and 25.1-fold higher than in the host strain. Overall, these findings suggest that the flow cytometry-based plating-free system can be a convenient and efficient tool for strain engineering in fungal biotechnology. We expect this system to facilitate improvements of filamentous fungal strains for industrial applications. KEY POINTS: • Development of a flow cytometry-based plating-free (FCPF) system is presented. • Application of FCPF system in M. thermophila and A. niger for glucoamylase platform. • Hyper-produced strains MtYM6 and AnLM3 for glucoamylase production are generated.
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Affiliation(s)
- Yu-Jing Yang
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, China
- 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
| | - Yin Liu
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, China
- 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
| | - Dan-Dan 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
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Wen-Zhu Guo
- 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
| | - Li-Xian Wang
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Xing-Ji Wang
- Longda Biotechnology Inc, 276400, Linyi, Shandong, China
| | - He-Xin Lv
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, China
| | - Yang Yang
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, 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.
| | - Chao-Guang 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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Insights into the Lignocellulose-Degrading Enzyme System of Humicola grisea var. thermoidea Based on Genome and Transcriptome Analysis. Microbiol Spectr 2021; 9:e0108821. [PMID: 34523973 PMCID: PMC8557918 DOI: 10.1128/spectrum.01088-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Humicola grisea var. thermoidea is a thermophilic ascomycete and important enzyme producer that has an efficient enzymatic system with a broad spectrum of thermostable carbohydrate-active (CAZy) enzymes. These enzymes can be employed in lignocellulose biomass deconstruction and other industrial applications. In this work, the genome of H. grisea var. thermoidea was sequenced. The acquired sequence reads were assembled into a total length of 28.75 Mbp. Genome features correlate with what was expected for thermophilic Sordariomycetes. The transcriptomic data showed that sugarcane bagasse significantly upregulated genes related to primary metabolism and polysaccharide deconstruction, especially hydrolases, at both pH 5 and pH 8. However, a number of exclusive and shared genes between the pH values were found, especially at pH 8. H. grisea expresses an average of 211 CAZy enzymes (CAZymes), which are capable of acting in different substrates. The top upregulated genes at both pH values represent CAZyme-encoding genes from different classes, including acetylxylan esterase, endo-1,4-β-mannosidase, exoglucanase, and endoglucanase genes. For the first time, the arsenal that the thermophilic fungus H. grisea var. thermoidea possesses to degrade the lignocellulosic biomass is shown. Carbon source and pH are of pivotal importance in regulating gene expression in this organism, and alkaline pH is a key regulatory factor for sugarcane bagasse hydrolysis. This work paves the way for the genetic manipulation and robust biotechnological applications of this fungus. IMPORTANCE Most studies regarding the use of fungi as enzyme producers for biomass deconstruction have focused on mesophile species, whereas the potential of thermophiles has been evaluated less. This study revealed, through genome and transcriptome analyses, the genetic repertoire of the biotechnological relevant thermophile fungus Humicola grisea. Comparative genomics helped us to further understand the biology and biotechnological potential of H. grisea. The results demonstrate that this fungus possesses an arsenal of carbohydrate-active (CAZy) enzymes to degrade the lignocellulosic biomass. Indeed, it expresses more than 200 genes encoding CAZy enzymes when cultivated in sugarcane bagasse. Carbon source and pH are key factors for regulating the gene expression in this organism. This work shows, for the first time, the great potential of H. grisea as an enzyme producer and a gene donor for biotechnological applications and provides the base for the genetic manipulation and robust biotechnological applications of this fungus.
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Sethupathy S, Morales GM, Li Y, Wang Y, Jiang J, Sun J, Zhu D. Harnessing microbial wealth for lignocellulose biomass valorization through secretomics: a review. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:154. [PMID: 34225772 PMCID: PMC8256616 DOI: 10.1186/s13068-021-02006-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/26/2021] [Indexed: 05/10/2023]
Abstract
The recalcitrance of lignocellulosic biomass is a major constraint to its high-value use at industrial scale. In nature, microbes play a crucial role in biomass degradation, nutrient recycling and ecosystem functioning. Therefore, the use of microbes is an attractive way to transform biomass to produce clean energy and high-value compounds. The microbial degradation of lignocelluloses is a complex process which is dependent upon multiple secreted enzymes and their synergistic activities. The availability of the cutting edge proteomics and highly sensitive mass spectrometry tools make possible for researchers to probe the secretome of microbes and microbial consortia grown on different lignocelluloses for the identification of hydrolytic enzymes of industrial interest and their substrate-dependent expression. This review summarizes the role of secretomics in identifying enzymes involved in lignocelluloses deconstruction, the development of enzyme cocktails and the construction of synthetic microbial consortia for biomass valorization, providing our perspectives to address the current challenges.
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Affiliation(s)
- Sivasamy Sethupathy
- School of the Environment and Safety Engineering, Biofuels Institute, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Gabriel Murillo Morales
- School of the Environment and Safety Engineering, Biofuels Institute, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Yixuan Li
- School of the Environment and Safety Engineering, Biofuels Institute, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Yongli Wang
- School of the Environment and Safety Engineering, Biofuels Institute, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Jianxiong Jiang
- School of the Environment and Safety Engineering, Biofuels Institute, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Jianzhong Sun
- School of the Environment and Safety Engineering, Biofuels Institute, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Daochen Zhu
- School of the Environment and Safety Engineering, Biofuels Institute, Jiangsu University, Zhenjiang, 212013, Jiangsu, China.
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Kun RS, Garrigues S, Di Falco M, Tsang A, de Vries RP. Blocking utilization of major plant biomass polysaccharides leads Aspergillus niger towards utilization of minor components. Microb Biotechnol 2021; 14:1683-1698. [PMID: 34114741 PMCID: PMC8313289 DOI: 10.1111/1751-7915.13835] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/08/2021] [Accepted: 05/10/2021] [Indexed: 11/28/2022] Open
Abstract
Fungi produce a wide range of enzymes that allow them to grow on diverse plant biomass. Wheat bran is a low-cost substrate with high potential for biotechnological applications. It mainly contains cellulose and (arabino)xylan, as well as starch, proteins, lipids and lignin to a lesser extent. In this study, we dissected the regulatory network governing wheat bran degradation in Aspergillus niger to assess the relative contribution of the regulators to the utilization of this plant biomass substrate. Deletion of genes encoding transcription factors involved in (hemi-)cellulose utilization (XlnR, AraR, ClrA and ClrB) individually and in combination significantly reduced production of polysaccharide-degrading enzymes, but retained substantial growth on wheat bran. Proteomic analysis suggested the ability of A. niger to grow on other carbon components, such as starch, which was confirmed by the additional deletion of the amylolytic regulator AmyR. Growth was further reduced but not impaired, indicating that other minor components provide sufficient energy for residual growth, displaying the flexibility of A. niger, and likely other fungi, in carbon utilization. Better understanding of the complexity and flexibility of fungal regulatory networks will facilitate the generation of more efficient fungal cell factories that use plant biomass as a substrate.
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Affiliation(s)
- Roland S. Kun
- Fungal PhysiologyWesterdijk Fungal Biodiversity Institute & Fungal Molecular PhysiologyUtrecht UniversityUppsalalaan 8Utrecht3584 CTThe Netherlands
| | - Sandra Garrigues
- Fungal PhysiologyWesterdijk Fungal Biodiversity Institute & Fungal Molecular PhysiologyUtrecht UniversityUppsalalaan 8Utrecht3584 CTThe Netherlands
| | - Marcos Di Falco
- Centre for Structural and Functional GenomicsConcordia University7141 Sherbrooke Street WestMontrealQCH4B 1R6Canada
| | - Adrian Tsang
- Centre for Structural and Functional GenomicsConcordia University7141 Sherbrooke Street WestMontrealQCH4B 1R6Canada
| | - Ronald P. de Vries
- Fungal PhysiologyWesterdijk Fungal Biodiversity Institute & Fungal Molecular PhysiologyUtrecht UniversityUppsalalaan 8Utrecht3584 CTThe Netherlands
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Arntzen MØ, Bengtsson O, Várnai A, Delogu F, Mathiesen G, Eijsink VGH. Quantitative comparison of the biomass-degrading enzyme repertoires of five filamentous fungi. Sci Rep 2020; 10:20267. [PMID: 33219291 PMCID: PMC7679414 DOI: 10.1038/s41598-020-75217-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 10/07/2020] [Indexed: 12/26/2022] Open
Abstract
The efficiency of microorganisms to degrade lignified plants is of great importance in the Earth's carbon cycle, but also in industrial biorefinery processes, such as for biofuel production. Here, we present a large-scale proteomics approach to investigate and compare the enzymatic response of five filamentous fungi when grown on five very different substrates: grass (sugarcane bagasse), hardwood (birch), softwood (spruce), cellulose and glucose. The five fungi included the ascomycetes Aspergillus terreus, Trichoderma reesei, Myceliophthora thermophila, Neurospora crassa and the white-rot basidiomycete Phanerochaete chrysosporium, all expressing a diverse repertoire of enzymes. In this study, we present comparable quantitative protein abundance values across five species and five diverse substrates. The results allow for direct comparison of fungal adaptation to the different substrates, give indications as to the substrate specificity of individual carbohydrate-active enzymes (CAZymes), and reveal proteins of unknown function that are co-expressed with CAZymes. Based on the results, we present a quantitative comparison of 34 lytic polysaccharide monooxygenases (LPMOs), which are crucial enzymes in biomass deconstruction.
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Affiliation(s)
- Magnus Ø Arntzen
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Ås, Norway.
| | - Oskar Bengtsson
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Ås, Norway
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Ås, Norway
| | - Francesco Delogu
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Ås, Norway
| | - Geir Mathiesen
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Ås, Norway
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Massarente VS, de Araujo Zanoni J, Gomes E, Bonilla-Rodriguez GO. Biochemical characterization of endoglucanases produced by Myceliophthora thermophila M.7.7 in solid-state culture. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2020. [DOI: 10.1016/j.bcab.2020.101684] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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15
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Kadowaki MAS, Higasi PMR, de Godoy MO, de Araújo EA, Godoy AS, Prade RA, Polikarpov I. Enzymatic versatility and thermostability of a new aryl-alcohol oxidase from Thermothelomyces thermophilus M77. Biochim Biophys Acta Gen Subj 2020; 1864:129681. [PMID: 32653619 DOI: 10.1016/j.bbagen.2020.129681] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 06/14/2020] [Accepted: 06/30/2020] [Indexed: 01/23/2023]
Abstract
Background Fungal aryl-alcohol oxidases (AAOx) are extracellular flavoenzymes that belong to glucose-methanol-choline oxidoreductase family and are responsible for the selective conversion of primary aromatic alcohols into aldehydes and aromatic aldehydes to their corresponding acids, with concomitant production of hydrogen peroxide (H2O2) as by-product. The H2O2 can be provided to lignin degradation pathway, a biotechnological property explored in biofuel production. In the thermophilic fungus Thermothelomyces thermophilus (formerly Myceliophthora thermophila), just one AAOx was identified in the exo-proteome. Methods The glycosylated and non-refolded crystal structure of an AAOx from T. thermophilus at 2.6 Å resolution was elucidated by X-ray crystallography combined with small-angle X-ray scattering (SAXS) studies. Moreover, biochemical analyses were carried out to shed light on enzyme substrate specificity and thermostability. Results This flavoenzyme harbors a flavin adenine dinucleotide as a cofactor and is able to oxidize aromatic substrates and 5-HMF. Our results also show that the enzyme has similar oxidation rates for bulky or simple aromatic substrates such as cinnamyl and veratryl alcohols. Moreover, the crystal structure of MtAAOx reveals an open active site, which might explain observed specificity of the enzyme. Conclusions MtAAOx shows previously undescribed structural differences such as a fully accessible catalytic tunnel, heavy glycosylation and Ca2+ binding site providing evidences for thermostability and activity of the enzymes from AA3_2 subfamily. General significance Structural and biochemical analyses of MtAAOx could be important for comprehension of aryl-alcohol oxidases structure-function relationships and provide additional molecular tools to be used in future biotechnological applications.
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Affiliation(s)
- Marco Antonio Seiki Kadowaki
- São Carlos Institute of Physics, University of São Paulo, Av. Trabalhador São-carlense, 400, São Carlos, SP 13566-590, Brazil.
| | - Paula Miwa Rabelo Higasi
- São Carlos Institute of Physics, University of São Paulo, Av. Trabalhador São-carlense, 400, São Carlos, SP 13566-590, Brazil
| | - Mariana Ortiz de Godoy
- São Carlos Institute of Physics, University of São Paulo, Av. Trabalhador São-carlense, 400, São Carlos, SP 13566-590, Brazil
| | - Evandro Ares de Araújo
- São Carlos Institute of Physics, University of São Paulo, Av. Trabalhador São-carlense, 400, São Carlos, SP 13566-590, Brazil
| | - Andre Schutzer Godoy
- São Carlos Institute of Physics, University of São Paulo, Av. Trabalhador São-carlense, 400, São Carlos, SP 13566-590, Brazil
| | - Rolf Alexander Prade
- Departments of Microbiology & Molecular Genetics and Biochemistry & Molecular Biology, Oklahoma State University, OK, USA
| | - Igor Polikarpov
- São Carlos Institute of Physics, University of São Paulo, Av. Trabalhador São-carlense, 400, São Carlos, SP 13566-590, Brazil.
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Li F, Liu Q, Li X, Zhang C, Li J, Sun W, Liu D, Xiao D, Tian C. Construction of a new thermophilic fungus Myceliophthora thermophila platform for enzyme production using a versatile 2A peptide strategy combined with efficient CRISPR-Cas9 system. Biotechnol Lett 2020; 42:1181-1191. [PMID: 32253539 DOI: 10.1007/s10529-020-02882-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 03/31/2020] [Indexed: 12/26/2022]
Abstract
OBJECTIVE To construct a new thermophilic platform for glucoamylase production through 2A peptide strategy combined with CRISPR-Cas9 system using Myceliophthora thermophila as host, thermophilic filamentous fungus with industrial attractiveness to produce enzymes and chemicals from biomass. RESULTS We adapted the viral 2A peptide approach for M. thermophila and constructed a bicistronic vector for co-expressing two heterologous genes MhglaA and egfp. We obtained positive transformants OE-MhglaA-gfp overexpressing MhGlaA-9 ×His-2A-eGFP through convenient fluorescence screening, western blotting and RT-qPCR. We purified and characterized the recombinant MhGlaA, which exhibited stability in a broader pH range of 3.0-9.0 and thermostable stability at 65 °C, suggesting its potential industrial application. Furthermore, to improve glucoamylase secretion, we genetically engineered the obtained strain OE-MhglaA-gfp through our efficient CRISPR/Cas9 system and generated the quintuple mutant OE-MhglaA-gfpOE-amyRΔalp-1Δres-1Δcre-1, in which protein productivity and amylase activity were increased by approximately 12.0- and 8.2-fold compared with WT. CONCLUSIONS The 2A peptide approach worked well in M. thermophila and can be used to heterologously co-express two different proteins, and thus in combination with efficient CRISPR-Cas system will accelerate establishing hyper-secretion platforms for biotechnological applications.
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Affiliation(s)
- Fangya Li
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.,Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Qian Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Xiaolin Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Chenyang Zhang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Jingen Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Wenliang Sun
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Dandan Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Dongguang Xiao
- 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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17
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de Vries RP, Mäkelä MR. Genomic and Postgenomic Diversity of Fungal Plant Biomass Degradation Approaches. Trends Microbiol 2020; 28:487-499. [PMID: 32396827 DOI: 10.1016/j.tim.2020.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/15/2019] [Accepted: 01/16/2020] [Indexed: 10/25/2022]
Abstract
Plant biomass degradation by fungi is a widely studied and applied field of science, due to its relevance for the global carbon cycle and many biotechnological applications. Before the genome era, many of the in-depth studies focused on a relatively small number of species, whereas now, many species can be addressed in detail, revealing the large variety in the approach used by fungi to degrade plant biomass. This variation is found at many levels and includes genomic adaptation to the preferred biomass component, but also different approaches to degrade this component by diverse sets of activities encoded in the genome. Even larger differences have been observed using transcriptome and proteome studies, even between closely related species, suggesting a high level of adaptation in individual species. A better understanding of the drivers of this diversity could be highly valuable in developing more efficient biotechnology approaches for the enzymatic conversion of plant biomass.
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Affiliation(s)
- Ronald P de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Utrecht, The Netherlands.
| | - Miia R Mäkelä
- Department of Microbiology, University of Helsinki, Helsinki, Finland
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18
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Tian L, Shi S, Ma L, Tran LSP, Tian C. Community structures of the rhizomicrobiomes of cultivated and wild soybeans in their continuous cropping. Microbiol Res 2020; 232:126390. [PMID: 31855689 DOI: 10.1016/j.micres.2019.126390] [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: 08/19/2019] [Revised: 11/15/2019] [Accepted: 12/03/2019] [Indexed: 11/15/2022]
Abstract
Continuous cropping of soybean often causes significant declines in yields of soybean because of the outbreaks of soil-borne fungal diseases. It has been reported that wild crops often harbour a unique microbiome to benefit the host plants. Thus, it is necessary to find the different community structures of the rhizomicrobiomes associated with cultivated and wild soybeans in their continuous cropping. In this study, we simulated monocropping of cultivated and wild soybeans under greenhouse conditions to investigate the rhizomicrobiomes of both soybeans. Results indicated that the bacterial community structure still maintained a changing trend after four continuous planting seasons, while fungal community structure showed a stable trend as indicated by the high similarity in the fungal community structure between the third and fourth planting rotations in both soybeans. In addition, by comparing the continuous cropping of the two soybeans, we found different fungal groups in their rhizospheres between the wild and cultivated soybeans following each passage. Spizellomycetaceae was more highly enriched in the rhizosphere following cultivation of the cultivated soybean, while Chaetomiaceae and Orbiliaceae were more highly enriched in the rhizosphere of wild soybean. Taken together, results of this study suggested that although there was the same trend of stabilized fungal development in the rhizospheres of both soybeans, wild soybean rhizosphere had different fungal groups compared with that of cultivated soybean following their continuous cropping. The findings of this study may provide useful information for the farmers with regard to planting soybean, especially when they consider growing soybean in monoculture.
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Affiliation(s)
- Lei Tian
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China
| | - Shaohua Shi
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China
| | - Lina Ma
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lam-Son Phan Tran
- Institute of Research and Development, Duy Tan University, 03 Quang Trung, Da Nang, Vietnam.
| | - Chunjie Tian
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China.
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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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20
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Improving cellulases production by Myceliophthora thermophila through disruption of protease genes. Biotechnol Lett 2019; 42:219-229. [DOI: 10.1007/s10529-019-02777-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 11/26/2019] [Indexed: 02/07/2023]
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21
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Mondo SJ, Jiménez DJ, Hector RE, Lipzen A, Yan M, LaButti K, Barry K, van Elsas JD, Grigoriev IV, Nichols NN. Genome expansion by allopolyploidization in the fungal strain Coniochaeta 2T2.1 and its exceptional lignocellulolytic machinery. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:229. [PMID: 31572496 PMCID: PMC6757388 DOI: 10.1186/s13068-019-1569-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 09/13/2019] [Indexed: 05/03/2023]
Abstract
BACKGROUND Particular species of the genus Coniochaeta (Sordariomycetes) exhibit great potential for bioabatement of furanic compounds and have been identified as an underexplored source of novel lignocellulolytic enzymes, especially Coniochaeta ligniaria. However, there is a lack of information about their genomic features and metabolic capabilities. Here, we report the first in-depth genome/transcriptome survey of a Coniochaeta species (strain 2T2.1). RESULTS The genome of Coniochaeta sp. strain 2T2.1 has a size of 74.53 Mbp and contains 24,735 protein-encoding genes. Interestingly, we detected a genome expansion event, resulting ~ 98% of the assembly being duplicated with 91.9% average nucleotide identity between the duplicated regions. The lack of gene loss, as well as the high divergence and strong genome-wide signatures of purifying selection between copies indicates that this is likely a recent duplication, which arose through hybridization between two related Coniochaeta-like species (allopolyploidization). Phylogenomic analysis revealed that 2T2.1 is related Coniochaeta sp. PMI546 and Lecythophora sp. AK0013, which both occur endophytically. Based on carbohydrate-active enzyme (CAZy) annotation, we observed that even after in silico removal of its duplicated content, the 2T2.1 genome contains exceptional lignocellulolytic machinery. Moreover, transcriptomic data reveal the overexpression of proteins affiliated to CAZy families GH11, GH10 (endoxylanases), CE5, CE1 (xylan esterases), GH62, GH51 (α-l-arabinofuranosidases), GH12, GH7 (cellulases), and AA9 (lytic polysaccharide monoxygenases) when the fungus was grown on wheat straw compared with glucose as the sole carbon source. CONCLUSIONS We provide data that suggest that a recent hybridization between the genomes of related species may have given rise to Coniochaeta sp. 2T2.1. Moreover, our results reveal that the degradation of arabinoxylan, xyloglucan and cellulose are key metabolic processes in strain 2T2.1 growing on wheat straw. Different genes for key lignocellulolytic enzymes were identified, which can be starting points for production, characterization and/or supplementation of enzyme cocktails used in saccharification of agricultural residues. Our findings represent first steps that enable a better understanding of the reticulate evolution and "eco-enzymology" of lignocellulolytic Coniochaeta species.
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Affiliation(s)
- Stephen J. Mondo
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
- Bioagricultural Science and Pest Management Department, Colorado State University, Fort Collins, CO 80521 USA
| | - Diego Javier Jiménez
- Microbiomes and Bioenergy Research Group, Department of Biological Sciences, Universidad de los Andes, Carrera 1 No 18A-12, Bogotá, Colombia
| | - Ronald E. Hector
- Bioenergy Research Unit, National Center for Agricultural Utilization Research, USDA-ARS, Peoria, IL 61604 USA
| | - Anna Lipzen
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Mi Yan
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Kurt LaButti
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Kerrie Barry
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Jan Dirk van Elsas
- Cluster of Microbial Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Igor V. Grigoriev
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA 94720-3102 USA
| | - Nancy N. Nichols
- Bioenergy Research Unit, National Center for Agricultural Utilization Research, USDA-ARS, Peoria, IL 61604 USA
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dos Santos Gomes AC, Falkoski D, Battaglia E, Peng M, Nicolau de Almeida M, Coconi Linares N, Meijnen JP, Visser J, de Vries RP. Myceliophthora thermophila Xyr1 is predominantly involved in xylan degradation and xylose catabolism. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:220. [PMID: 31534479 PMCID: PMC6745793 DOI: 10.1186/s13068-019-1556-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 08/31/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Myceliophthora thermophila is a thermophilic ascomycete fungus that is used as a producer of enzyme cocktails used in plant biomass saccharification. Further development of this species as an industrial enzyme factory requires a detailed understanding of its regulatory systems driving the production of plant biomass-degrading enzymes. In this study, we analyzed the function of MtXlr1, an ortholog of the (hemi-)cellulolytic regulator XlnR first identified in another industrially relevant fungus, Aspergillus niger. RESULTS The Mtxlr1 gene was deleted and the resulting strain was compared to the wild type using growth profiling and transcriptomics. The deletion strain was unable to grow on xylan and d-xylose, but showed only a small growth reduction on l-arabinose, and grew similar to the wild type on Avicel and cellulose. These results were supported by the transcriptome analyses which revealed reduction of genes encoding xylan-degrading enzymes, enzymes of the pentose catabolic pathway and putative pentose transporters. In contrast, no or minimal effects were observed for the expression of cellulolytic genes. CONCLUSIONS Myceliophthora thermophila MtXlr1 controls the expression of xylanolytic genes and genes involved in pentose transport and catabolism, but has no significant effects on the production of cellulases. It therefore resembles more the role of its ortholog in Neurospora crassa, rather than the broader role described for this regulator in A. niger and Trichoderma reesei. By revealing the range of genes controlled by MtXlr1, our results provide the basic knowledge for targeted strain improvement by overproducing or constitutively activating this regulator, to further improve the biotechnological value of M. thermophila.
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Affiliation(s)
- Ana Carolina dos Santos Gomes
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Daniel Falkoski
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
- Present Address: Novozymes Latin America, Professor Francisco Ribeiro Street 683, Araucária, PR 83707-660 Brazil
| | - Evy Battaglia
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Mao Peng
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Maira Nicolau de Almeida
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
- DuPont Industrial Biosciences, Archimedesweg 30, 2333 CN Leiden, The Netherlands
- Present Address: Federal University of São João del Rei, Praça Dom Helvécio, 74, São João del Rei, Minas Gerais Brazil
| | - Nancy Coconi Linares
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Jean-Paul Meijnen
- DuPont Industrial Biosciences, Archimedesweg 30, 2333 CN Leiden, The Netherlands
- Present Address: Dutch DNA Biotech BV, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Jaap Visser
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Ronald P. de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
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Chadha BS, Kaur B, Basotra N, Tsang A, Pandey A. Thermostable xylanases from thermophilic fungi and bacteria: Current perspective. BIORESOURCE TECHNOLOGY 2019; 277:195-203. [PMID: 30679061 DOI: 10.1016/j.biortech.2019.01.044] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 01/06/2019] [Accepted: 01/08/2019] [Indexed: 06/09/2023]
Abstract
Thermostable xylanases from thermophilic fungi and bacteria have a wide commercial acceptability in feed, food, paper and pulp and bioconversion of lignocellulosics with an estimated annual market of USD 500 Million. The genome wide analysis of thermophilic fungi clearly shows the presence of elaborate genetic information coding for multiple xylanases primarily coding for GH10, GH11 in addition to GH7 and GH30 xylanases. The transcriptomics and proteome profiling has given insight into the differential expression of these xylanases in some of the thermophilic fungi. Bioprospecting has resulted in identification of novel thermophilic xylanases that have been endorsed by the industrial houses for heterologous over- expression and formulations. The future use of xylanases is expected to increase exponentially for their role in biorefineries. The discovery of new and improvement of existing xylanases using molecular tools such as directed evolution is expected to be the mainstay to meet increasing demand of thermostable xylanases.
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Affiliation(s)
- B S Chadha
- Department of Microbiology, Guru Nanak Dev University, Amritsar 143 005, India.
| | - Baljit Kaur
- Department of Microbiology, Guru Nanak Dev University, Amritsar 143 005, India
| | - Neha Basotra
- Department of Microbiology, Guru Nanak Dev University, Amritsar 143 005, India
| | - Adrian Tsang
- Center for Structural and Functional Genomics, Concordia University, Sherbrooke Street West, Montreal, Quebec H4B 1R6, Canada.
| | - Ashok Pandey
- Centre for Innovation and Translational Research, CSIR-Indian Institute of Toxicology Research, Lucknow 226 001, India.
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24
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Killer toxin-like chitinases in filamentous fungi: Structure, regulation and potential roles in fungal biology. FUNGAL BIOL REV 2019. [DOI: 10.1016/j.fbr.2018.11.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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25
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Chen J, Guo X, Zhu M, Chen C, Li D. Polysaccharide monooxygenase-catalyzed oxidation of cellulose to glucuronic acid-containing cello-oligosaccharides. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:42. [PMID: 30858879 PMCID: PMC6391835 DOI: 10.1186/s13068-019-1384-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 02/20/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Polysaccharide monooxygenases (PMOs) play an important role in the enzymatic degradation of cellulose. They have been demonstrated to able to C6-oxidize cellulose to produce C6-hexodialdoses. However, the biological function of C6 oxidation of PMOs remains unknown. In particular, it is unclear whether C6-hexodialdoses can be further oxidized to uronic acid (glucuronic acid-containing oligosaccharides). RESULTS A PMO gene, Hipmo1, was isolated from Humicola insolens and expressed in Pichia pastoris. This PMO (HiPMO1), belonging to the auxiliary activity 9 (AA9) family, was shown to able to cleave cellulose to yield non-oxidized and oxidized cello-oligosaccharides. The enzyme oxidizes C6 positions in cellulose to form glucuronic acid-containing cello-oligosaccharides, followed by hydrolysis with beta-glucosidase and beta-glucuronidase to yield glucose, glucuronic acid, and saccharic acid. This indicates that HiPMO1 can catalyze C6 oxidation of hydroxyl groups of cellulose to carboxylic groups. CONCLUSIONS HiPMO1 oxidizes C6 of cellulose to form glucuronic acid-containing cello-oligosaccharides followed by hydrolysis with beta-glucosidase and beta-glucuronidase to yield glucose, glucuronic acid, and saccharic acid, and even possibly by beta-eliminative cleavage to produce unsaturated cello-oligosaccharides. This study provides a new mechanism for cellulose cleavage by C6 oxidation of HiPMO1.
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Affiliation(s)
- Jinyin Chen
- Department of Mycology, Shandong Agricultural University, Taian, 271018 Shandong China
| | - Xiuna Guo
- Department of Mycology, Shandong Agricultural University, Taian, 271018 Shandong China
| | - Min Zhu
- Department of Mycology, Shandong Agricultural University, Taian, 271018 Shandong China
| | - Chen Chen
- Department of Mycology, Shandong Agricultural University, Taian, 271018 Shandong China
| | - Duochuan Li
- Department of Mycology, Shandong Agricultural University, Taian, 271018 Shandong China
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26
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Developments and opportunities in fungal strain engineering for the production of novel enzymes and enzyme cocktails for plant biomass degradation. Biotechnol Adv 2019; 37:107361. [PMID: 30825514 DOI: 10.1016/j.biotechadv.2019.02.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/11/2019] [Accepted: 02/23/2019] [Indexed: 12/26/2022]
Abstract
Fungal strain engineering is commonly used in many areas of biotechnology, including the production of plant biomass degrading enzymes. Its aim varies from the production of specific enzymes to overall increased enzyme production levels and modification of the composition of the enzyme set that is produced by the fungus. Strain engineering involves a diverse range of methodologies, including classical mutagenesis, genetic engineering and genome editing. In this review, the main approaches for strain engineering of filamentous fungi in the field of plant biomass degradation will be discussed, including recent and not yet implemented methods, such as CRISPR/Cas9 genome editing and adaptive evolution.
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Abstract
Proteomics is the large-scale analysis of proteins rendered possible by modern mass spectrometry analysis methods capable of identifying thousands of peptides/proteins in a fast high-throughput manner. Here I describe protocols for the preparation of fungal culture protein samples for mass spectrometry-based proteomics analysis including protein sample cleanup, proteolytic digestion, LC-MS/MS separation, and database search protein identification.
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Affiliation(s)
- Marcos Rafael Di Falco
- Centre for Structural and Functional Genomics, Concordia University, Montreal, QC, Canada.
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28
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Nakamichi Y, Fouquet T, Ito S, Watanabe M, Matsushika A, Inoue H. Structural and functional characterization of a bifunctional GH30-7 xylanase B from the filamentous fungus Talaromyces cellulolyticus. J Biol Chem 2019; 294:4065-4078. [PMID: 30655295 DOI: 10.1074/jbc.ra118.007207] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 01/15/2019] [Indexed: 01/11/2023] Open
Abstract
Glucuronoxylanases are endo-xylanases and members of the glycoside hydrolase family 30 subfamilies 7 (GH30-7) and 8 (GH30-8). Unlike for the well-studied GH30-8 enzymes, the structural and functional characteristics of GH30-7 enzymes remain poorly understood. Here, we report the catalytic properties and three-dimensional structure of GH30-7 xylanase B (Xyn30B) identified from the cellulolytic fungus Talaromyces cellulolyticus Xyn30B efficiently degraded glucuronoxylan to acidic xylooligosaccharides (XOSs), including an α-1,2-linked 4-O-methyl-d-glucuronosyl substituent (MeGlcA). Rapid analysis with negative-mode electrospray-ionization multistage MS (ESI(-)-MS n ) revealed that the structures of the acidic XOS products are the same as those of the hydrolysates (MeGlcA2Xyl n , n > 2) obtained with typical glucuronoxylanases. Acidic XOS products were further degraded by Xyn30B, releasing first xylobiose and then xylotetraose and xylohexaose as transglycosylation products. This hydrolase reaction was unique to Xyn30B, and the substrate was cleaved at the xylobiose unit from its nonreducing end, indicating that Xyn30B is a bifunctional enzyme possessing both endo-glucuronoxylanase and exo-xylobiohydrolase activities. The crystal structure of Xyn30B was determined as the first structure of a GH30-7 xylanase at 2.25 Å resolution, revealing that Xyn30B is composed of a pseudo-(α/β)8-catalytic domain, lacking an α6 helix, and a small β-rich domain. This structure and site-directed mutagenesis clarified that Arg46, conserved in GH30-7 glucuronoxylanases, is a critical residue for MeGlcA appendage-dependent xylan degradation. The structural comparison between Xyn30B and the GH30-8 enzymes suggests that Asn93 in the β2-α2 loop is involved in xylobiohydrolase activity. In summary, our findings indicate that Xyn30B is a bifunctional endo- and exo-xylanase.
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Affiliation(s)
| | - Thierry Fouquet
- the Polymer Chemistry Group, Research Institute for Sustainable Chemistry, AIST, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan, and
| | - Shotaro Ito
- the Bio-based Materials Chemistry Group, Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan
| | | | - Akinori Matsushika
- From the Bioconversion Group and.,the Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan
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29
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Liu Q, Li J, Gao R, Li J, Ma G, Tian C. CLR-4, a novel conserved transcription factor for cellulase gene expression in ascomycete fungi. Mol Microbiol 2018; 111:373-394. [DOI: 10.1111/mmi.14160] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/31/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Qian Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology; Chinese Academy of Sciences; Tianjin 300308 China
| | - Jingen Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology; Chinese Academy of Sciences; Tianjin 300308 China
| | - Ranran Gao
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology; Chinese Academy of Sciences; Tianjin 300308 China
| | - Jinyang Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology; Chinese Academy of Sciences; Tianjin 300308 China
| | - Guoli Ma
- 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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Guo H, Wang XD, Lee DJ. Proteomic researches for lignocellulose-degrading enzymes: A mini-review. BIORESOURCE TECHNOLOGY 2018; 265:532-541. [PMID: 29884341 DOI: 10.1016/j.biortech.2018.05.101] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 05/29/2018] [Accepted: 05/30/2018] [Indexed: 05/14/2023]
Abstract
Protective action of lignin/hemicellulose networks and crystalline structures of embedded cellulose render lignocellulose material resistant to external enzymatic attack. To eliminate this bottleneck, research has been conducted in which advanced proteomic techniques are applied to identify effective commercial hydrolytic enzymes. This mini-review summarizes researches on lignocellulose-degrading enzymes, the mechanisms of the responses of various lignocellulose-degrading strains and microbial communities to various carbon sources and various biomass substrates, post-translational modifications of lignocellulose-degrading enzymes, new lignocellulose-degrading strains, new lignocellulose-degrading enzymes and a new method of secretome analysis. The challenges in the practical use of enzymatic hydrolysis process to realize lignocellulose biorefineries are discussed, along with the prospects for the same.
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Affiliation(s)
- Hongliang Guo
- College of Food Engineering, Harbin University of Commerce, Harbin 150076, China
| | - Xiao-Dong Wang
- Research Center of Engineering Thermophysics, North China Electric Power University, Beijing 102206, China; School of Energy Power and Mechanical Engineering, North China Electric Power University, Beijing 102206, China
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan; Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.
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31
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Xu G, Li J, Liu Q, Sun W, Jiang M, Tian C. Transcriptional analysis of Myceliophthora thermophila on soluble starch and role of regulator AmyR on polysaccharide degradation. BIORESOURCE TECHNOLOGY 2018; 265:558-562. [PMID: 29843921 DOI: 10.1016/j.biortech.2018.05.086] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 05/21/2018] [Accepted: 05/22/2018] [Indexed: 05/27/2023]
Abstract
Thermophilic fungus Myceliophthora thermophila has great capacity for biomass degradation and is an attractive option for use as cell factory to produce chemicals directly from renewable polysaccharides, such as starch, rather than monomer glucose. To date, there has been no transcriptomic analysis of this thermophilic fungus on starch. This study determined the transcriptomic profile of M. thermophila responding to soluble starch and a 342-gene set was identified as a "starch regulon", including the major amylolytic enzyme (Mycth_72393). Its overexpression led to increased amylase activities on starch by 35%. Furthermore, overexpressing the key amylolytic enzyme regulator AmyR in M. thermophila significantly increased amylase activity by 30%. Deletion of amyR by the CRISPR/Cas9 system led to the relief of carbon catabolite repression and 3-fold increased lignocellulase activities on cellulose. This study will accelerate rational fungal strain engineering for biochemical production from biomass substrates such as raw corn starch and even crop straw.
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Affiliation(s)
- Guanbao Xu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University. Nanjing 211800, China
| | - Jingen Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences. Tianjin 300308, China
| | - Qian Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences. Tianjin 300308, China
| | - Wenliang Sun
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences. Tianjin 300308, China
| | - Min Jiang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University. Nanjing 211800, 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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32
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Balabanova L, Slepchenko L, Son O, Tekutyeva L. Biotechnology Potential of Marine Fungi Degrading Plant and Algae Polymeric Substrates. Front Microbiol 2018; 9:1527. [PMID: 30050513 PMCID: PMC6052901 DOI: 10.3389/fmicb.2018.01527] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 06/19/2018] [Indexed: 12/19/2022] Open
Abstract
Filamentous fungi possess the metabolic capacity to degrade environment organic matter, much of which is the plant and algae material enriched with the cell wall carbohydrates and polyphenol complexes that frequently can be assimilated by only marine fungi. As the most renewable energy feedstock on the Earth, the plant or algae polymeric substrates induce an expression of microbial extracellular enzymes that catalyze their cleaving up to the component sugars. However, the question of what the marine fungi contributes to the plant and algae material biotransformation processes has yet to be highlighted sufficiently. In this review, we summarized the potential of marine fungi alternatively to terrestrial fungi to produce the biotechnologically valuable extracellular enzymes in response to the plant and macroalgae polymeric substrates as sources of carbon for their bioconversion used for industries and bioremediation.
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Affiliation(s)
- Larissa Balabanova
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russia
- Innovative Technology Center, Far Eastern Federal University, Vladivostok, Russia
| | - Lubov Slepchenko
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russia
- Innovative Technology Center, Far Eastern Federal University, Vladivostok, Russia
| | - Oksana Son
- Innovative Technology Center, Far Eastern Federal University, Vladivostok, Russia
| | - Liudmila Tekutyeva
- Innovative Technology Center, Far Eastern Federal University, Vladivostok, Russia
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33
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Quantitative multiplexed profiling of Penicillium funiculosum secretome grown on polymeric cellulase inducers and glucose. J Proteomics 2018; 179:150-160. [PMID: 29597011 DOI: 10.1016/j.jprot.2018.03.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 02/16/2018] [Accepted: 03/20/2018] [Indexed: 11/22/2022]
Abstract
Filamentous fungi respond to the need to secure utilisable carbon from their growth milieu by secreting unique extracellular proteins depending upon the types of polymeric substrates. We have here profiled the variations in the secretome pattern of a non-model hypercellulolytic fungus - Penicillium funiculosum, grown in minimal media containing four different polymeric cellulase inducers, i.e., Avicel, wheat bran, ammonium-pretreated wheat straw and Avicel & wheat bran, and glucose over its early and late log phases of growth. Of the 137 secreted proteins validated at 1% FDR, we identified the quantified proteins in three clusters as early, persistently or lately expressed. The type of carbon substrate present in the culture media significantly affected the levels of cellulolytic enzymes expression by the fungus. The top abundant proteins quantified in the secretome for Avicel and wheat bran were cellobiohydrolaseI [GH7-CBM1], cellobiohydrolaseII [GH6-CBM1], β-glucosidase [GH3], arabinofuranosidase [GH51] and β-xylosidase [GH3], with bicupin being highest in case of wheat straw. Our results further suggested that the fungus secreted the extracellular proteins in waves, such that the initial responders act to hydrolyse the composite substrates in the culture environment before the second wave of proteins which tend to be more tailored to the specific substrate in the cultivating media. BIOLOGICAL SIGNIFICANCE In this article, we have comprehensively examined the dynamics of the secretome of a non-model hypercellulolytic fungus produced in response to model and composite cellulase inducers. Our study has provided additional insights into how the fungus enzyme machinery responds to the presence of different polymeric cellulase inducers over the two different growth phases (early growth and late growth phase). The comprehensive typing and quantification of the different proteins present in the secretomes of the cellulolytic fungal strains in response to diverse nutrient sources hold many prospects in understanding the fungus unique enzyme machinery and dynamics for the downstream biotechnological applications.
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Wang J, Gong Y, Zhao S, Liu G. A new regulator of cellulase and xylanase in the thermophilic fungus Myceliophthora thermophila strain ATCC 42464. 3 Biotech 2018. [PMID: 29527447 DOI: 10.1007/s13205-017-1069-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Myceliophthora thermophila (ATCC 42464) is a thermophilic fungus that produces cellulolytic enzymes with high thermal stability. Unlike its mesophile counterparts, study on gene expression regulation of cellulolytic enzymes in M. thermophila is inadequate. This work identified the function of MHR1, a putative transcription regulator of cellulolytic enzymes in M. thermophila that was found through RNA-Seq based gene expression profile analysis. RNA interference was used to study the role of MHR1. A recombinant plasmid, pUC19-Ppdc-mhr1-Tpdc, which contained the RNAi sequence for mhr1 was constructed and transformed into M. thermophila. One of the transformants, MtR5, in which the RNA interference efficiency was the highest, was used for the following studies. In the mhr1-silenced strain MtR5, the filter paper hydrolyzing activity was 1.33-fold; β-1, 4-endoglucanase activity was 1.65-fold; and xylanase activity was 1.48-fold higher than those of the parental strain after induction, respectively, by wheat straw powder. qRT-PCR showed that gene expression of cbh1, cbh2, egl3 and xyr1 were 9.56-, 37.36-, 56.14- and 28.30-fold higher in MtR5 than in wild type, respectively. Our findings suggest that the transcription factor MHR1 of M. thermophila can repress cellulase and xylanase activities. Silenced mhr1 results in increased expression not only of the main cellulase genes, but also of the positive regulatory gene xyr1. This work is relevant to the development of M. thermophila as an industrial production host for cellulolytic and hemicellulolytic enzymes, which could be used to degrade a wide range of different biomass, converting lignocellulosic feedstock into sugar precursors for biofuels.
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Affiliation(s)
- Juan Wang
- 1Shenzhen Key Laboratory of Microbial Genetic Engineering, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, People's Republic of China
| | - Yanfen Gong
- 1Shenzhen Key Laboratory of Microbial Genetic Engineering, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, People's Republic of China
- Shenzhen Key Laboratory of Marine Bioresources and Ecology, Shenzhen, 518060 People's Republic of China
| | - Shengming Zhao
- 1Shenzhen Key Laboratory of Microbial Genetic Engineering, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, People's Republic of China
| | - Gang Liu
- 1Shenzhen Key Laboratory of Microbial Genetic Engineering, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, People's Republic of China
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Kadowaki MAS, Higasi P, de Godoy MO, Prade RA, Polikarpov I. Biochemical and structural insights into a thermostable cellobiohydrolase from Myceliophthora thermophila. FEBS J 2018; 285:559-579. [PMID: 29222836 DOI: 10.1111/febs.14356] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 10/20/2017] [Accepted: 12/05/2017] [Indexed: 12/27/2022]
Abstract
Cellobiohydrolases hydrolyze cellulose, a linear polymer with glucose monomers linked exclusively by β-1,4 glycosidic linkages. The widespread hydrogen bonding network tethers individual cellulose polymers forming crystalline cellulose, which prevent the access of hydrolytic enzymes and water molecules. The most abundant enzyme secreted by Myceliophthora thermophila M77 in response to the presence of biomass is the cellobiohydrolase MtCel7A, which is composed by a GH7-catalytic domain (CD), a linker, and a CBM1-type carbohydrate-binding module. GH7 cellobiohydrolases have been studied before, and structural models have been proposed. However, currently available GH7 crystal structures only define separate catalytic domains and/or cellulose-binding modules and do not include the full-length structures that are involved in shaping the catalytic mode of operation. In this study, we determined the 3D structure of catalytic domain using X-ray crystallography and retrieved the full-length enzyme envelope via small-angle X-ray scattering (SAXS) technique. The SAXS data reveal a tadpole-like molecular shape with a rigid linker connecting the CD and CBM. Our biochemical studies show that MtCel7A has higher catalytic efficiency and thermostability as well as lower processivity when compared to the well-studied TrCel7A from Trichoderma reesei. Based on a comparison of the crystallographic structures of CDs and their molecular dynamic simulations, we demonstrate that MtCel7A has considerably higher flexibility than TrCel7A. In particular, loops that cover the active site are more flexible and undergo higher conformational fluctuations, which might account for decreased processivity and enhanced enzymatic efficiency. Our statistical coupling analysis suggests co-evolution of amino acid clusters comprising the catalytic site of MtCel7A, which correlate with the steps in the catalytic cycle of the enzyme. DATABASE The atomic coordinates and structural factors of MtCel7A have been deposited in the Protein Data Bank with accession number 5W11.
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Affiliation(s)
| | - Paula Higasi
- São Carlos Institute of Physics, University of São Paulo, Brazil
| | | | - Rolf A Prade
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Igor Polikarpov
- São Carlos Institute of Physics, University of São Paulo, Brazil
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Muraleedharan MN, Zouraris D, Karantonis A, Topakas E, Sandgren M, Rova U, Christakopoulos P, Karnaouri A. Effect of lignin fractions isolated from different biomass sources on cellulose oxidation by fungal lytic polysaccharide monooxygenases. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:296. [PMID: 30386433 PMCID: PMC6204277 DOI: 10.1186/s13068-018-1294-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 10/15/2018] [Indexed: 05/18/2023]
Abstract
BACKGROUND Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes that oxidatively cleave recalcitrant lignocellulose in the presence of oxygen or hydrogen peroxide as co-substrate and a reducing agent as electron donor. One of the possible systems that provide electrons to the LPMOs active site and promote the polysaccharide degradation involves the mediation of phenolic agents, such as lignin, low-molecular-weight lignin-derived compounds and other plant phenols. In the present work, the interaction of the bulk insoluble lignin fraction extracted from pretreated biomass with LPMOs and the ability to provide electrons to the active site of the enzymes is studied. RESULTS The catalytic efficiency of three LPMOs, namely MtLPMO9 with C1/C4 regioselectivity, PcLPMO9D which is a C1 active LPMO and NcLPMO9C which is a C4 LPMO, was evaluated in the presence of different lignins. It was correlated with the physicochemical and structural properties of lignins, such as the molecular weight and the composition of aromatic and aliphatic hydroxyl groups. Moreover, the redox potential of lignins was determined with the use of large amplitude Fourier Transform alternating current cyclic voltammetry method and compared to the formal potential of the Cu (II) center in the active site of the LPMOs, providing more information about the lignin-LPMO interaction. The results demonstrated the existence of low-molecular weight lignin-derived compounds that are diffused in the reaction medium, which are able to reduce the enzyme active site and subsequently utilize additional electrons from the insoluble lignin fraction to promote the LPMO oxidative activity. Regarding the bulk lignin fractions, those isolated from the organosolv pretreated materials served as the best candidates in supplying electrons to the soluble compounds and, finally, to the enzymes. This difference, based on biomass pretreatment, was also demonstrated by the activity of LPMOs on natural substrates in the presence and absence of ascorbic acid as additional reducing agent. CONCLUSIONS Lignins can support the action of LPMOs and serve indirectly as electron donors through low-molecular-weight soluble compounds. This ability depends on their physicochemical and structural properties and is related to the biomass source and pretreatment method.
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Affiliation(s)
- Madhu Nair Muraleedharan
- Biochemical Process Engineering, Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden
| | - Dimitrios Zouraris
- Laboratory of Physical Chemistry and Applied Electrochemistry, School of Chemical Engineering, National Technical University of Athens, Athens, Greece
| | - Antonis Karantonis
- Laboratory of Physical Chemistry and Applied Electrochemistry, School of Chemical Engineering, National Technical University of Athens, Athens, Greece
| | - Evangelos Topakas
- Biochemical Process Engineering, Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden
- Biotechnology Laboratory, Department of Synthesis and Development of Industrial Processes, School of Chemical Engineering, National Technical University of Athens, Athens, Greece
| | - Mats Sandgren
- Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Ulrika Rova
- Biochemical Process Engineering, Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden
| | - Paul Christakopoulos
- Biochemical Process Engineering, Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden
| | - Anthi Karnaouri
- Biochemical Process Engineering, Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden
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Identification of Genes Involved in the Degradation of Lignocellulose Using Comparative Transcriptomics. Methods Mol Biol 2017; 1588:279-298. [PMID: 28417376 DOI: 10.1007/978-1-4939-6899-2_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Lignocellulosic biomass represents an abundant, renewable resource that can be used to produce biofuels, low-cost livestock feed, and high-value chemicals. The potential of this resource has led to intensive research efforts to develop cost effective methods to breakdown lignocellulose. The efficiency with which the anaerobic fungi (phylum Neocallimastigomycota) degrade plant biomass is well recognized and in recent years has received renewed interest. Transcriptomics has been used to identify enzymes that are expressed by these fungi and are involved in the degradation of a range of lignocellulose feedstocks. The transcriptome is the entire complement of coding and noncoding RNA transcripts that are expressed by a cell under a particular set of conditions. Monitoring changes in gene expression can provide fundamental information about the biology of an organism. Here we outline a general methodology that will enable researchers to conduct comparative transcriptomic studies with the goal of identifying enzymes involved in the degradation of the plant cell wall. The method described here includes growth of fungal cultures, isolation and sequencing of RNA, and a basic description of data analysis for bioinformatic identification of differentially expressed transcripts.
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Voshol GP, Vijgenboom E, Punt PJ. The discovery of novel LPMO families with a new Hidden Markov model. BMC Res Notes 2017; 10:105. [PMID: 28222763 PMCID: PMC5320794 DOI: 10.1186/s13104-017-2429-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 02/15/2017] [Indexed: 12/20/2022] Open
Abstract
Background Renewable biopolymers, such as cellulose, starch and chitin are highly resistance to enzymatic degradation. Therefore, there is a need to upgrade current degradation processes by including novel enzymes. Lytic polysaccharide mono-oxygenases (LPMOs) can disrupt recalcitrant biopolymers, thereby enhancing hydrolysis by conventional enzymes. However, novel LPMO families are difficult to identify using existing methods. Therefore, we developed a novel profile Hidden Markov model (HMM) and used it to mine genomes of ascomycetous fungi for novel LPMOs. Results We constructed a structural alignment and verified that the alignment was correct. In the alignment we identified several known conserved features, such as the histidine brace and the N/Q/E-X-F/Y motif and previously unidentified conserved proline and glycine residues. These residues are distal from the active site, suggesting a role in structure rather than activity. The multiple protein alignment was subsequently used to build a profile Hidden Markov model. This model was initially tested on manually curated datasets and proved to be both sensitive (no false negatives) and specific (no false positives). In some of the genomes analyzed we identified a yet unknown LPMO family. This new family is mostly confined to the phyla of Ascomycota and Basidiomycota and the class of Oomycota. Genomic clustering indicated that at least some members might be involved in the degradation of β-glucans, while transcriptomic data suggested that others are possibly involved in the degradation of pectin. Conclusions The newly developed profile hidden Markov Model was successfully used to mine fungal genomes for a novel family of LPMOs. However, the model is not limited to bacterial and fungal genomes. This is illustrated by the fact that the model was also able to identify another new LPMO family in Drosophila melanogaster. Furthermore, the Hidden Markov model was used to verify the more distant blast hits from the new fungal family of LPMOs, which belong to the Bivalves, Stony corals and Sea anemones. So this Hidden Markov model (Additional file 3) will help the broader scientific community in identifying other yet unknown LPMOs. Electronic supplementary material The online version of this article (doi:10.1186/s13104-017-2429-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gerben P Voshol
- Molecular Microbiology and Health, Institute of Biology Leiden, Leiden University, Leiden, The Netherlands
| | - Erik Vijgenboom
- Molecular Microbiology and Health, Institute of Biology Leiden, Leiden University, Leiden, The Netherlands
| | - Peter J Punt
- Molecular Microbiology and Health, Institute of Biology Leiden, Leiden University, Leiden, The Netherlands. .,Dutch DNA Biotech B.V., Utrechtseweg 48, 3703HE, Zeist, The Netherlands.
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Daly P, van Munster JM, Blythe MJ, Ibbett R, Kokolski M, Gaddipati S, Lindquist E, Singan VR, Barry KW, Lipzen A, Ngan CY, Petzold CJ, Chan LJG, Pullan ST, Delmas S, Waldron PR, Grigoriev IV, Tucker GA, Simmons BA, Archer DB. Expression of Aspergillus niger CAZymes is determined by compositional changes in wheat straw generated by hydrothermal or ionic liquid pretreatments. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:35. [PMID: 28184248 PMCID: PMC5294722 DOI: 10.1186/s13068-017-0700-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 01/05/2017] [Indexed: 05/21/2023]
Abstract
BACKGROUND The capacity of fungi, such as Aspergillus niger, to degrade lignocellulose is harnessed in biotechnology to generate biofuels and high-value compounds from renewable feedstocks. Most feedstocks are currently pretreated to increase enzymatic digestibility: improving our understanding of the transcriptomic responses of fungi to pretreated lignocellulosic substrates could help to improve the mix of activities and reduce the production costs of commercial lignocellulose saccharifying cocktails. RESULTS We investigated the responses of A. niger to untreated, ionic liquid and hydrothermally pretreated wheat straw over a 5-day time course using RNA-seq and targeted proteomics. The ionic liquid pretreatment altered the cellulose crystallinity while retaining more of the hemicellulosic sugars than the hydrothermal pretreatment. Ionic liquid pretreatment of straw led to a dynamic induction and repression of genes, which was correlated with the higher levels of pentose sugars saccharified from the ionic liquid-pretreated straw. Hydrothermal pretreatment of straw led to reduced levels of transcripts of genes encoding carbohydrate-active enzymes as well as the derived proteins and enzyme activities. Both pretreatments abolished the expression of a large set of genes encoding pectinolytic enzymes. These reduced levels could be explained by the removal of parts of the lignocellulose by the hydrothermal pretreatment. The time course also facilitated identification of temporally limited gene induction patterns. CONCLUSIONS The presented transcriptomic and biochemical datasets demonstrate that pretreatments caused modifications of the lignocellulose, to both specific structural features as well as the organisation of the overall lignocellulosic structure, that determined A. niger transcript levels. The experimental setup allowed reliable detection of substrate-specific gene expression patterns as well as hitherto non-expressed genes. Our data suggest beneficial effects of using untreated and IL-pretreated straw, but not HT-pretreated straw, as feedstock for CAZyme production.
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Affiliation(s)
- Paul Daly
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
- Fungal Physiology, CBS-KNAW Fungal Biodiversity Centre, Utrecht University, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
| | - Jolanda M. van Munster
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
- Chemical Biology, Manchester Institute for Biotechnology, University of Manchester, 131 Princess Street, Manchester, M1 7DN UK
| | - 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, Walnut Creek, CA 94598 USA
| | - Vasanth R. Singan
- US Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Kerrie W. Barry
- US Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Anna Lipzen
- US Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Chew Yee Ngan
- US Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | | | | | - Steven T. Pullan
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
- TB Programme, Microbiology Services, Public Health England, Salisbury, UK
| | - Stéphane Delmas
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
- UPMC, Univ. Paris 06, CNRS UMR7238, Sorbonne Universités, 15 rue de l’Ecole de Médecine, 75270 Paris, France
| | - Paul R. Waldron
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | - Igor V. Grigoriev
- US Department of Energy Joint Genome Institute, Walnut Creek, 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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Antonopoulou I, Leonov L, Jütten P, Cerullo G, Faraco V, Papadopoulou A, Kletsas D, Ralli M, Rova U, Christakopoulos P. Optimized synthesis of novel prenyl ferulate performed by feruloyl esterases from Myceliophthora thermophila in microemulsions. Appl Microbiol Biotechnol 2017; 101:3213-3226. [PMID: 28078397 PMCID: PMC5380708 DOI: 10.1007/s00253-017-8089-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/13/2016] [Accepted: 12/21/2016] [Indexed: 11/03/2022]
Abstract
Five feruloyl esterases (FAEs; EC 3.1.1.73), FaeA1, FaeA2, FaeB1, and FaeB2 from Myceliophthora thermophila C1 and MtFae1a from M. thermophila ATCC 42464, were tested for their ability to catalyze the transesterification of vinyl ferulate (VFA) with prenol in detergentless microemulsions. Reaction conditions were optimized investigating parameters such as the medium composition, the substrate concentration, the enzyme load, the pH, the temperature, and agitation. FaeB2 offered the highest transesterification yield (71.5 ± 0.2%) after 24 h of incubation at 30 °C using 60 mM VFA, 1 M prenol, and 0.02 mg FAE/mL in a mixture comprising of 53.4:43.4:3.2 v/v/v n-hexane:t-butanol:100 mM MOPS-NaOH, pH 6.0. At these conditions, the competitive side hydrolysis of VFA was 4.7-fold minimized. The ability of prenyl ferulate (PFA) and its corresponding ferulic acid (FA) to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals was significant and similar (IC50 423.39 μM for PFA, 329.9 μM for FA). PFA was not cytotoxic at 0.8-100 μM (IC50 220.23 μM) and reduced intracellular reactive oxygen species (ROS) in human skin fibroblasts at concentrations ranging between 4 and 20 μM as determined with the dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay.
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Affiliation(s)
- Io Antonopoulou
- Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 97187, Luleå, Sweden
| | - Laura Leonov
- DuPont Industrial Biosciences, Nieuwe Kanaal 7-S, 6709 PA, Wageningen, The Netherlands
| | - Peter Jütten
- Taros Chemicals GmbH & Co. KG, Emil Figge Str 76a, 44227, Dortmund, Germany
| | - Gabriella Cerullo
- Department of Chemical Sciences, University of Naples "Federico II", Via Cintia 4, 80126, Naples, Italy
| | - Vincenza Faraco
- Department of Chemical Sciences, University of Naples "Federico II", Via Cintia 4, 80126, Naples, Italy
| | - Adamantia Papadopoulou
- Institute of Biosciences and Applications NCSR "Demokritos," Laboratory of Cell Proliferation and Aging, T. Patriarchou Grigoriou & Neapoleos, 15310, Athens, Greece
| | - Dimitris Kletsas
- Institute of Biosciences and Applications NCSR "Demokritos," Laboratory of Cell Proliferation and Aging, T. Patriarchou Grigoriou & Neapoleos, 15310, Athens, Greece
| | - Marianna Ralli
- Korres Natural Products, 57 Km National Road, 32011, Lamia, Athens, Greece
| | - Ulrika Rova
- Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 97187, Luleå, Sweden
| | - Paul Christakopoulos
- Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 97187, Luleå, Sweden.
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Benocci T, Aguilar-Pontes MV, Zhou M, Seiboth B, de Vries RP. Regulators of plant biomass degradation in ascomycetous fungi. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:152. [PMID: 28616076 PMCID: PMC5468973 DOI: 10.1186/s13068-017-0841-x] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 06/06/2017] [Indexed: 05/05/2023]
Abstract
Fungi play a major role in the global carbon cycle because of their ability to utilize plant biomass (polysaccharides, proteins, and lignin) as carbon source. Due to the complexity and heterogenic composition of plant biomass, fungi need to produce a broad range of degrading enzymes, matching the composition of (part of) the prevalent substrate. This process is dependent on a network of regulators that not only control the extracellular enzymes that degrade the biomass, but also the metabolic pathways needed to metabolize the resulting monomers. This review will summarize the current knowledge on regulation of plant biomass utilization in fungi and compare the differences between fungal species, focusing in particular on the presence or absence of the regulators involved in this process.
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Affiliation(s)
- Tiziano Benocci
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Maria Victoria Aguilar-Pontes
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Miaomiao Zhou
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Bernhard Seiboth
- Research Area Biochemical Technology, Institute of Chemical and Biological Engineering, TU Wien, 1060 Vienna, Austria
| | - Ronald P. de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
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Liu Q, Gao R, Li J, Lin L, Zhao J, Sun W, Tian C. Development of a genome-editing CRISPR/Cas9 system in thermophilic fungal Myceliophthora species and its application to hyper-cellulase production strain engineering. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:1. [PMID: 28053662 PMCID: PMC5209885 DOI: 10.1186/s13068-016-0693-9] [Citation(s) in RCA: 240] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Accepted: 12/20/2016] [Indexed: 05/02/2023]
Abstract
BACKGROUND Over the past 3 years, the CRISPR/Cas9 system has revolutionized the field of genome engineering. However, its application has not yet been validated in thermophilic fungi. Myceliophthora thermophila, an important thermophilic biomass-degrading fungus, has attracted industrial interest for the production of efficient thermostable enzymes. Genetic manipulation of Myceliophthora is crucial for metabolic engineering and to unravel the mechanism of lignocellulose deconstruction. The lack of a powerful, versatile genome-editing tool has impeded the broader exploitation of M. thermophila in biotechnology. RESULTS In this study, a CRISPR/Cas9 system for efficient multiplexed genome engineering was successfully developed in the thermophilic species M. thermophila and M. heterothallica. This CRISPR/Cas9 system could efficiently mutate the imported amdS gene in the genome via NHEJ-mediated events. As a proof of principle, the genes of the cellulase production pathway, including cre-1, res-1, gh1-1, and alp-1, were chosen as editing targets. Simultaneous multigene disruptions of up to four of these different loci were accomplished with neomycin selection marker integration via a single transformation using the CRISPR/Cas9 system. Using this genome-engineering tool, multiple strains exhibiting pronounced hyper-cellulase production were generated, in which the extracellular secreted protein and lignocellulase activities were significantly increased (up to 5- and 13-fold, respectively) compared with the parental strain. CONCLUSIONS A genome-wide engineering system for thermophilic fungi was established based on CRISPR/Cas9. Successful expansion of this system without modification to M. heterothallica indicates it has wide adaptability and flexibility for use in other Myceliophthora species. This system could greatly accelerate strain engineering of thermophilic fungi for production of industrial enzymes, such as cellulases as shown in this study and possibly bio-based fuels and chemicals in the future.
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Affiliation(s)
- Qian Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Ranran Gao
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Jingen Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Liangcai Lin
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Junqi Zhao
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Wenliang 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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dos Santos HB, Bezerra TMS, Pradella JGC, Delabona P, Lima D, Gomes E, Hartson SD, Rogers J, Couger B, Prade R. Myceliophthora thermophila M77 utilizes hydrolytic and oxidative mechanisms to deconstruct biomass. AMB Express 2016; 6:103. [PMID: 27807811 PMCID: PMC5093097 DOI: 10.1186/s13568-016-0276-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 10/27/2016] [Indexed: 12/23/2022] Open
Abstract
Biomass is abundant, renewable and useful for biofuel production as well as chemical priming for plastics and composites. Deconstruction of biomass by enzymes is perceived as recalcitrant while an inclusive breakdown mechanism remains to be discovered. Fungi such as Myceliophthora thermophila M77 appear to decompose natural biomass sources quite well. This work reports on this fungus fermentation property while producing cellulolytic enzymes using natural biomass substrates. Little hydrolytic activity was detected, insufficient to explain the large amount of biomass depleted in the process. Furthermore, this work makes a comprehensive account of extracellular proteins and describes how secretomes redirect their qualitative protein content based on the nature and chemistry of the nutritional source. Fungus grown on purified cellulose or on natural biomass produced secretomes constituted by: cellobiohydrolases, cellobiose dehydrogenase, β-1,3 glucanase, β-glucosidases, aldose epimerase, glyoxal oxidase, GH74 xyloglucanase, galactosidase, aldolactonase and polysaccharide monooxygenases. Fungus grown on a mixture of purified hemicellulose fractions (xylans, arabinans and arabinoxylans) produced many enzymes, some of which are listed here: xylosidase, mixed β-1,3(4) glucanase, β-1,3 glucanases, β-glucosidases, β-mannosidase, β-glucosidases, galactosidase, chitinases, polysaccharide lyase, endo β-1,6 galactanase and aldose epimerase. Secretomes produced on natural biomass displayed a comprehensive set of enzymes involved in hydrolysis and oxidation of cellulose, hemicellulose-pectin and lignin. The participation of oxidation reactions coupled to lignin decomposition in the breakdown of natural biomass may explain the discrepancy observed for cellulose decomposition in relation to natural biomass fermentation experiments.
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Affiliation(s)
- Hévila Brognaro dos Santos
- Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP Brazil
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol, Rua Giuseppe Máximo Scolfaro, 10.000, Bairro Guará, Campinas, SP CEP 13083-970 Brazil
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74078 USA
| | - Thaís Milena Souza Bezerra
- Laboratório de Enzimologia, Instituto de Química, UNESP, Araraquara, São Paulo Brazil
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74078 USA
| | - José G. C. Pradella
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol, Rua Giuseppe Máximo Scolfaro, 10.000, Bairro Guará, Campinas, SP CEP 13083-970 Brazil
| | - Priscila Delabona
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol, Rua Giuseppe Máximo Scolfaro, 10.000, Bairro Guará, Campinas, SP CEP 13083-970 Brazil
| | - Deise Lima
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol, Rua Giuseppe Máximo Scolfaro, 10.000, Bairro Guará, Campinas, SP CEP 13083-970 Brazil
| | - Eleni Gomes
- Laboratório de Microbiologia e Bioquímica Aplicada, Departamento de Biologia, IBILCE/UNESP, Rua Cristovão Colombo, 2265 Bairro Jd. Nazareth, São José do Rio Preto, SP CEP 15054-000 Brazil
| | - Steve D. Hartson
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078 USA
| | - Janet Rogers
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078 USA
| | - Brian Couger
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74078 USA
| | - Rolf Prade
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74078 USA
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Basotra N, Kaur B, Di Falco M, Tsang A, Chadha BS. Mycothermus thermophilus (Syn. Scytalidium thermophilum): Repertoire of a diverse array of efficient cellulases and hemicellulases in the secretome revealed. BIORESOURCE TECHNOLOGY 2016; 222:413-421. [PMID: 27744242 DOI: 10.1016/j.biortech.2016.10.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/04/2016] [Accepted: 10/05/2016] [Indexed: 05/25/2023]
Abstract
Mycothermus thermophilus (Syn. Scytalidium thermophilum/Humicola insolens), a thermophilic fungus, is being reported to produce appreciable titers of cellulases and hemicellulases during shake flask culturing on cellulose/wheat-bran/rice straw based production medium. The sequential and differential expression profile of endoglucanases, β-glucosidases, cellobiohydrolases and xylanases using zymography was studied. Mass spectrometry analysis of secretome (Q-TOF LC/MS) revealed a total of 240 proteins with 92 CAZymes of which 62 glycosyl hydrolases belonging to 30 different families were present. Cellobiohydrolase I (17.42%), β glucosidase (8.69%), endoglucanase (6.2%), xylanase (4.16%) and AA9 (3.95%) were the major proteins in the secretome. In addition, carbohydrate esterases, polysaccharide lyases, auxiliary activity and a variety of carbohydrate binding modules (CBM) were identified using genomic database of the culture indicating to an elaborate genetic potential of this strain for hydrolysis of lignocellulosics. The cellulases from the strain hydrolyzed alkali treated rice straw and bagasse into fermentable sugars efficiently.
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Affiliation(s)
- Neha Basotra
- Department of Microbiology, Guru Nanak Dev University, Amritsar 143005, Punjab, India.
| | - Baljit Kaur
- Department of Microbiology, Guru Nanak Dev University, Amritsar 143005, Punjab, India.
| | - Marcos Di Falco
- Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec H4B 1R6, Canada.
| | - Adrian Tsang
- Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec H4B 1R6, Canada.
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Ferrari AR, Rozeboom HJ, Dobruchowska JM, van Leeuwen SS, Vugts ASC, Koetsier MJ, Visser J, Fraaije MW. Discovery of a Xylooligosaccharide Oxidase from Myceliophthora thermophila C1. J Biol Chem 2016; 291:23709-23718. [PMID: 27629413 PMCID: PMC5095424 DOI: 10.1074/jbc.m116.741173] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 09/12/2016] [Indexed: 11/06/2022] Open
Abstract
By inspection of the predicted proteome of the fungus Myceliophthora thermophila C1 for vanillyl-alcohol oxidase (VAO)-type flavoprotein oxidases, a putative oligosaccharide oxidase was identified. By homologous expression and subsequent purification, the respective protein could be obtained. The protein was found to contain a bicovalently bound FAD cofactor. By screening a large number of carbohydrates, several mono- and oligosaccharides could be identified as substrates. The enzyme exhibits a strong substrate preference toward xylooligosaccharides; hence it is named xylooligosaccharide oxidase (XylO). Chemical analyses of the product formed upon oxidation of xylobiose revealed that the oxidation occurs at C1, yielding xylobionate as product. By elucidation of several XylO crystal structures (in complex with a substrate mimic, xylose, and xylobiose), the residues that tune the unique substrate specificity and regioselectivity could be identified. The discovery of this novel oligosaccharide oxidase reveals that the VAO-type flavoprotein family harbors oxidases tuned for specific oligosaccharides. The unique substrate profile of XylO hints at a role in the degradation of xylan-derived oligosaccharides by the fungus M. thermophila C1.
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Affiliation(s)
| | | | - Justyna M Dobruchowska
- Microbial Physiology Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen
| | - Sander S van Leeuwen
- Microbial Physiology Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen
| | | | | | - Jaap Visser
- the Fungal Genetics and Technology Consultancy, 6700 AJ Wageningen, The Netherlands
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Mukherjee S, Khowala S. Unraveling the secretome of Termitomyces clypeatus grown on agroresidues as a potential source for bioethanol production. Process Biochem 2016. [DOI: 10.1016/j.procbio.2015.11.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Rai R, Kaur B, Singh S, Di Falco M, Tsang A, Chadha BS. Evaluation of secretome of highly efficient lignocellulolytic Penicillium sp. Dal 5 isolated from rhizosphere of conifers. BIORESOURCE TECHNOLOGY 2016; 216:958-67. [PMID: 27341464 DOI: 10.1016/j.biortech.2016.06.040] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 06/04/2016] [Accepted: 06/06/2016] [Indexed: 05/23/2023]
Abstract
Penicillium sp. (Dal 5) isolated from rhizosphere of conifers from Dalhousie (Himachal Pradesh, India) was found to be an efficient cellulolytic strain. The culture under shake flask on CWR (cellulose, wheat bran and rice straw) medium produced appreciably higher levels of endoglucanase (35.69U/ml), β-glucosidase (4.20U/ml), cellobiohydrolase (2.86U/ml), FPase (1.2U/ml) and xylanase (115U/ml) compared to other Penicillium strains reported in literature. The mass spectroscopy analysis of Penicillium sp. Dal 5 secretome identified 108 proteins constituting an array of CAZymes including glycosyl hydrolases (GH) belonging to 24 different families, polysaccharide lyases (PL), carbohydrate esterases (CE), lytic polysaccharide mono-oxygenases (LPMO) in addition to swollenin and a variety of carbohydrate binding modules (CBM) indicating an elaborate genetic potential of this strain for hydrolysis of lignocellulosics. Further, the culture extract was evaluated for hydrolysis of alkali treated rice straw, wheat straw, bagasse and corn cob at 10% substrate loading rate.
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Affiliation(s)
- Rohit Rai
- Department of Microbiology, Guru Nanak Dev University, Amritsar 143005, Punjab, India
| | - Baljit Kaur
- Department of Microbiology, Guru Nanak Dev University, Amritsar 143005, Punjab, India
| | - Surender Singh
- Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Macros Di Falco
- Centre for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec H4B 1R6, Canada
| | - Adrian Tsang
- Centre for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec H4B 1R6, Canada
| | - B S Chadha
- Department of Microbiology, Guru Nanak Dev University, Amritsar 143005, Punjab, India.
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Daly P, van Munster JM, Kokolski M, Sang F, Blythe MJ, Malla S, Velasco de Castro Oliveira J, Goldman GH, Archer DB. Transcriptomic responses of mixed cultures of ascomycete fungi to lignocellulose using dual RNA-seq reveal inter-species antagonism and limited beneficial effects on CAZyme expression. Fungal Genet Biol 2016; 102:4-21. [PMID: 27150814 PMCID: PMC5476202 DOI: 10.1016/j.fgb.2016.04.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 04/20/2016] [Accepted: 04/29/2016] [Indexed: 12/15/2022]
Abstract
First genome-wide transcriptional response in fungal mixed species straw cultures. In mixed cultures, rRNA abundance was used to predict RNA-seq read abundance. Subset of P. chrysogenum CAZy with mixed cultures increased abundance pattern. Lack of overall higher CAZy transcripts/activities due to inter-species antagonism. Induction of secondary metabolite producing gene clusters in mixed cultures.
Gaining new knowledge through fungal monoculture responses to lignocellulose is a widely used approach that can lead to better cocktails for lignocellulose saccharification (the enzymatic release of sugars which are subsequently used to make biofuels). However, responses in lignocellulose mixed cultures are rarely studied in the same detail even though in nature fungi often degrade lignocellulose as mixed communities. Using a dual RNA-seq approach, we describe the first study of the transcriptional responses of wild-type strains of Aspergillus niger, Trichoderma reesei and Penicillium chrysogenum in two and three mixed species shake-flask cultures with wheat straw. Based on quantification of species-specific rRNA, a set of conditions was identified where mixed cultures could be sampled so as to obtain sufficient RNA-seq reads for analysis from each species. The number of differentially-expressed genes varied from a couple of thousand to fewer than one hundred. The proportion of carbohydrate active enzyme (CAZy) encoding transcripts was lower in the majority of the mixed cultures compared to the respective straw monocultures. A small subset of P. chrysogenum CAZy genes showed five to ten-fold significantly increased transcript abundance in a two-species mixed culture with T. reesei. However, a substantial number of T. reesei CAZy transcripts showed reduced abundance in mixed cultures. The highly induced genes in mixed cultures indicated that fungal antagonism was a major part of the mixed cultures. In line with this, secondary metabolite producing gene clusters showed increased transcript abundance in mixed cultures and also mixed cultures with T. reesei led to a decrease in the mycelial biomass of A. niger. Significantly higher monomeric sugar release from straw was only measured using a minority of the mixed culture filtrates and there was no overall improvement. This study demonstrates fungal interaction with changes in transcripts, enzyme activities and biomass in the mixed cultures and whilst there were minor beneficial effects for CAZy transcripts and activities, the competitive interaction between T. reesei and the other fungi was the most prominent feature of this study.
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Affiliation(s)
- Paul Daly
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Jolanda M van Munster
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Matthew Kokolski
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Fei Sang
- Deep Seq, Faculty of Medicine and Health Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
| | - Martin J Blythe
- Deep Seq, Faculty of Medicine and Health Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
| | - Sunir Malla
- Deep Seq, Faculty of Medicine and Health Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
| | - Juliana Velasco de Castro Oliveira
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Rua Giuseppe Máximo Scolfaro 10000, Campinas, São Paulo 13083-100, Brazil.
| | - Gustavo H Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Avenida do Café, Ribeirão Preto, São Paulo 14040-903, Brazil.
| | - David B Archer
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
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Aguilar-Pontes MV, Zhou M, van der Horst S, Theelen B, de Vries RP, van den Brink J. Sexual crossing of thermophilic fungus Myceliophthora heterothallica improved enzymatic degradation of sugar beet pulp. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:41. [PMID: 26900400 PMCID: PMC4761134 DOI: 10.1186/s13068-016-0460-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 02/10/2016] [Indexed: 05/21/2023]
Abstract
BACKGROUND Enzymatic degradation of plant biomass requires a complex mixture of many different enzymes. Like most fungi, thermophilic Myceliophthora species therefore have a large set of enzymes targeting different linkages in plant polysaccharides. The majority of these enzymes have not been functionally characterized, and their role in plant biomass degradation is unknown. The biotechnological challenge is to select the right set of enzymes to efficiently degrade a particular biomass. This study describes a strategy using sexual crossing and screening with the thermophilic fungus Myceliophthora heterothallica to identify specific enzymes associated with improved sugar beet pulp saccharification. RESULTS Two genetically diverse M. heterothallica strains CBS 203.75 and CBS 663.74 were used to generate progenies with improved growth on sugar beet pulp. One progeny, named SBP.F1.2.11, had a different genetic pattern from the parental strains and had improved saccharification activity after the growth on 3 % sugar beet pulp. The improved SBP saccharification was not explained by altered activities of the major (hemi-)cellulases. Exo-proteome analysis of progeny and parental strains after 7-day growth on sugar beet pulp showed that only 17 of the 133 secreted CAZy enzymes were more abundant in progeny SBP.F1.2.11. Particularly one enzyme belonging to the carbohydrate esterase family 5 (CE5) was more abundant in SBP.F1.2.11. This CE5-CBM1 enzyme, named as Axe1, was phylogenetically related to acetyl xylan esterases. Biochemical characterization of Axe1 confirmed de-acetylation activity with optimal activities at 75-85 °C and pH 5.5-6.0. Supplementing Axe1 to CBS 203.75 enzyme set improved release of xylose and glucose from sugar beet pulp. CONCLUSIONS This study identified beneficial enzymes for sugar beet pulp saccharification by selecting progeny with improved growth on this particular substrate. Saccharification of sugar beet pulp was improved by supplementing enzyme mixtures with a previously uncharacterized CE5-CBM1 acetyl xylan esterase. This shows that sexual crossing and selection of M. heterothallica are the successful strategy to improve the composition of enzyme mixtures for efficient plant biomass degradation.
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Affiliation(s)
- Maria Victoria Aguilar-Pontes
- />Fungal Physiology, CBS-KNAW Fungal Biodiversity Centre, Utrecht, The Netherlands
- />Fungal Molecular Physiology, Utrecht University, Utrecht, The Netherlands
| | - Miaomiao Zhou
- />Fungal Physiology, CBS-KNAW Fungal Biodiversity Centre, Utrecht, The Netherlands
- />Fungal Molecular Physiology, Utrecht University, Utrecht, The Netherlands
| | - Sjors van der Horst
- />Fungal Physiology, CBS-KNAW Fungal Biodiversity Centre, Utrecht, The Netherlands
- />Fungal Molecular Physiology, Utrecht University, Utrecht, The Netherlands
| | - Bart Theelen
- />Yeast and Basidiomycete Research, CBS-KNAW Fungal Biodiversity Centre, Utrecht, The Netherlands
| | - Ronald P. de Vries
- />Fungal Physiology, CBS-KNAW Fungal Biodiversity Centre, Utrecht, The Netherlands
- />Fungal Molecular Physiology, Utrecht University, Utrecht, The Netherlands
| | - Joost van den Brink
- />Fungal Physiology, CBS-KNAW Fungal Biodiversity Centre, Utrecht, The Netherlands
- />Fungal Molecular Physiology, Utrecht University, Utrecht, The Netherlands
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Álvarez C, Reyes-Sosa FM, Díez B. Enzymatic hydrolysis of biomass from wood. Microb Biotechnol 2016; 9:149-56. [PMID: 26833542 PMCID: PMC4767290 DOI: 10.1111/1751-7915.12346] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 11/25/2015] [Accepted: 12/03/2015] [Indexed: 01/10/2023] Open
Abstract
Current research and development in cellulosic ethanol production has been focused mainly on agricultural residues and dedicated energy crops such as corn stover and switchgrass; however, woody biomass remains a very important feedstock for ethanol production. The precise composition of hemicellulose in the wood is strongly dependent on the plant species, therefore different types of enzymes are needed based on hemicellulose complexity and type of pretreatment. In general, hardwood species have much lower recalcitrance to enzymes than softwood. For hardwood, xylanases, beta‐xylosidases and xyloglucanases are the main hemicellulases involved in degradation of the hemicellulose backbone, while for softwood the effect of mannanases and beta‐mannosidases is more relevant. Furthermore, there are different key accessory enzymes involved in removing the hemicellulosic fraction and increasing accessibility of cellulases to the cellulose fibres improving the hydrolysis process. A diversity of enzymatic cocktails has been tested using from low to high densities of biomass (2–20% total solids) and a broad range of results has been obtained. The performance of recently developed commercial cocktails on hardwoods and softwoods will enable a further step for the commercialization of fuel ethanol from wood.
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Affiliation(s)
- Consolación Álvarez
- Department of Biotechnology, Abengoa Research, Campus Palmas Altas, C/Energía Solar no. 1, Seville, 41014, Spain
| | - Francisco Manuel Reyes-Sosa
- Department of Biotechnology, Abengoa Research, Campus Palmas Altas, C/Energía Solar no. 1, Seville, 41014, Spain
| | - Bruno Díez
- Department of Biotechnology, Abengoa Research, Campus Palmas Altas, C/Energía Solar no. 1, Seville, 41014, Spain
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