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Zhu Z, Zou G, Chai S, Xiao M, Wang Y, Wang P, Zhou Z. The protein methyltransferase TrSAM inhibits cellulase gene expression by interacting with the negative regulator ACE1 in Trichoderma reesei. Commun Biol 2024; 7:375. [PMID: 38548869 PMCID: PMC10978942 DOI: 10.1038/s42003-024-06072-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 03/19/2024] [Indexed: 04/01/2024] Open
Abstract
Protein methylation is a commonly posttranslational modification of transcriptional regulators to fine-tune protein function, however, whether this regulation strategy participates in the regulation of lignocellulase synthesis and secretion in Trichoderma reesei remains unexplored. Here, a putative protein methyltransferase (TrSAM) is screened from a T. reesei mutant with the ability to express heterologous β-glucosidase efficiently even under glucose repression. The deletion of its encoding gene trsam causes a significant increase of cellulase activities in all tested T. reesei strains, including transformants of expressing heterologous genes using cbh1 promotor. Further investigation confirms that TrSAM interacts with the cellulase negative regulator ACE1 via its amino acid residue Arg383, which causes a decrease in the ACE1-DNA binding affinity. The enzyme activity of a T. reesei strain harboring ACE1R383Q increases by 85.8%, whereas that of the strains with trsam or ace1 deletion increases by more than 100%. By contrast, the strain with ACE1R383K shows no difference to the parent strain. Taken together, our results demonstrate that TrSAM plays an important role in regulating the expression of cellulase and heterologous proteins initiated by cbh1 promotor through interacting with ACE1R383. Elimination and mutation of TrSAM and its downstream ACE1 alleviate the carbon catabolite repression (CCR) in expressing cellulase and heterologous protein in varying degrees. This provides a new solution for the exquisite modification of T. reesei chassis.
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Affiliation(s)
- Zhihua Zhu
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 FengLin Rd, Shanghai, 200032, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Gen Zou
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 FengLin Rd, Shanghai, 200032, China
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Institute of Edible Fungi, Shanghai Academy of Agricultural Science, 1000 Jinqi Rd, Shanghai, 201403, China
| | - Shunxing Chai
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 FengLin Rd, Shanghai, 200032, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Meili Xiao
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 FengLin Rd, Shanghai, 200032, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yinmei Wang
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 FengLin Rd, Shanghai, 200032, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Pingping Wang
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 FengLin Rd, Shanghai, 200032, China
| | - Zhihua Zhou
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 FengLin Rd, Shanghai, 200032, China.
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Zhang Y, Nada B, Baker SE, Evans JE, Tian C, Benz JP, Tamayo E. Unveiling a classical mutant in the context of the GH3 β-glucosidase family in Neurospora crassa. AMB Express 2024; 14:4. [PMID: 38180602 PMCID: PMC10770018 DOI: 10.1186/s13568-023-01658-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 12/23/2023] [Indexed: 01/06/2024] Open
Abstract
Classical fungal mutant strains obtained by mutagenesis have helped to elucidate fundamental metabolic pathways in the past. In the filamentous fungus Neurospora crassa, the gluc-1 strain was isolated long ago and characterized by its low level of β-glucosidase activity, which is essential for the degradation of cellulose, the most abundant biopolymer on Earth and the main polymeric component of the plant cell wall. Based on genomic resequencing, we hypothesized that the causative mutation resides in the β-glucosidase gene gh3-3 (bgl6, NCU08755). In this work, growth patterns, enzymatic activities and sugar utilization rates were analyzed in several mutant and overexpression strains related to gluc-1 and gh3-3. In addition, different mutants affected in the degradation and transport of cellobiose were analyzed. While overexpression of gh3-3 led to the recovery of β-glucosidase activity in the gluc-1 mutant, as well as normal utilization of cellobiose, the full gene deletion strain Δgh3-3 was found to behave differently than gluc-1 with lower secreted β-glucosidase activity, indicating a dominant role of the amino acid substitution in the point mutated gh3-3 gene of gluc-1. Our results furthermore confirm that GH3-3 is the major extracellular β-glucosidase in N. crassa and demonstrate that the two cellodextrin transporters CDT-1 and CDT-2 are essential for growth on cellobiose when the three main N. crassa β-glucosidases are absent. Overall, these findings provide valuable insight into the mechanisms of cellulose utilization in filamentous fungi, being an essential step in the efficient production of biorefinable sugars from agricultural and forestry plant biomass.
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Affiliation(s)
- Yuxin Zhang
- Fungal Biotechnology in Wood Science, Holzforschung München, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
| | - Basant Nada
- Fungal Biotechnology in Wood Science, Holzforschung München, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
| | - Scott E Baker
- DOE Joint BioEnergy Institute, Emeryville, CA, 94608, USA
- Microbial Molecular Phenotyping Group, Environmental Molecular Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - James E Evans
- Microbial Molecular Phenotyping Group, Environmental Molecular Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Chaoguang Tian
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - J Philipp Benz
- Fungal Biotechnology in Wood Science, Holzforschung München, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
| | - Elisabeth Tamayo
- Fungal Biotechnology in Wood Science, Holzforschung München, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany.
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Arai T, Wada M, Nishiguchi H, Takimura Y, Ishii J. Inducer-free recombinant protein production in Trichoderma reesei: secretory production of endogenous enzymes and heterologous nanobodies using glucose as the sole carbon source. Microb Cell Fact 2023; 22:103. [PMID: 37208691 DOI: 10.1186/s12934-023-02109-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 04/28/2023] [Indexed: 05/21/2023] Open
Abstract
BACKGROUND The filamentous fungus Trichoderma reesei has been used as a host organism for the production of lignocellulosic biomass-degrading enzymes. Although this microorganism has high potential for protein production, it has not yet been widely used for heterologous recombinant protein production. Transcriptional induction of the cellulase genes is essential for high-level protein production in T. reesei; however, glucose represses this transcriptional induction. Therefore, cellulose is commonly used as a carbon source for providing its degraded sugars such as cellobiose, which act as inducers to activate the strong promoters of the major cellulase (cellobiohydrolase 1 and 2 (cbh1 and cbh2) genes. However, replacement of cbh1 and/or cbh2 with a gene encoding the protein of interest (POI) for high productivity and occupancy of recombinant proteins remarkably impairs the ability to release soluble inducers from cellulose, consequently reducing the production of POI. To overcome this challenge, we first used an inducer-free biomass-degrading enzyme expression system, previously developed to produce cellulases and hemicellulases using glucose as the sole carbon source, for recombinant protein production using T. reesei. RESULTS We chose endogenous secretory enzymes and heterologous camelid small antibodies (nanobody) as model proteins. By using the inducer-free strain as a parent, replacement of cbh1 with genes encoding two intrinsic enzymes (aspartic protease and glucoamylase) and three different nanobodies (1ZVH, caplacizumab, and ozoralizumab) resulted in their high secretory productions using glucose medium without inducers such as cellulose. Based on signal sequences (carrier polypeptides) and protease inhibitors, additional replacement of cbh2 with the nanobody gene increased the percentage of POI to about 20% of total secreted proteins in T. reesei. This allowed the production of caplacizumab, a bivalent nanobody, to be increased to 9.49-fold (508 mg/L) compared to the initial inducer-free strain. CONCLUSIONS In general, whereas the replacement of major cellulase genes leads to extreme decrease in the degradation capacity of cellulose, our inducer-free system enabled it and achieved high secretory production of POI with increased occupancy in glucose medium. This system would be a novel platform for heterologous recombinant protein production in T. reesei.
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Affiliation(s)
- Toshiharu Arai
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, 640‑8580, Japan.
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
| | - Mayumi Wada
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, 640‑8580, Japan
| | - Hiroki Nishiguchi
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, 640‑8580, Japan
| | - Yasushi Takimura
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, 640‑8580, Japan
| | - Jun Ishii
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
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Gong M, Wang Y, Bao D, Jiang S, Chen H, Shang J, Wang X, Hnin Yu H, Zou G. Improving cold-adaptability of mesophilic cellulase complex with a novel mushroom cellobiohydrolase for efficient low-temperature ensiling. BIORESOURCE TECHNOLOGY 2023; 376:128888. [PMID: 36925076 DOI: 10.1016/j.biortech.2023.128888] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/07/2023] [Accepted: 03/10/2023] [Indexed: 06/18/2023]
Abstract
Low ambient temperature poses a challenge for rice straw-silage processing in cold climate regions, as cold limits enzyme and microbial activity in silages. Here, a novel cold-active cellobiohydrolase (VvCBHI-I) was isolated from Volvariella volvacea, which exhibited outstanding cellobiohydrolase activity at 10-30 °C. The crude cellulase complex in the VvCBHI-I-expressing transformant T1 retained 50% relative activity at 10 °C, while the wildtype Trichoderma reesei showed <5% of the activity. VvCBHI-I greatly improved the saccharification efficiency of the cellulase complex with pretreated rice straw as substrate at 10 °C. In rice straw silage, pH (<4.5) and lactic acid content (>4.6%) remained stable after 15-day ensiling with the cellulase complex from T1 and Lactobacillus plantarum. Moreover, the proportions of cellulose and hemicellulose decreased to 29.84% ± 0.15% and 21.25% ± 0.26% of the dried material. This demonstrates the crucial potential of mushroom-derived cold-active cellobiohydrolases in successful ensiling in cold regions.
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Affiliation(s)
- Ming Gong
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Institute of Edible Fungi, Shanghai Academy of Agriculture Science, 1000 Jinqi Rd, Fengxian 201403, Shanghai, China
| | - Ying Wang
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Institute of Edible Fungi, Shanghai Academy of Agriculture Science, 1000 Jinqi Rd, Fengxian 201403, Shanghai, China
| | - Dapeng Bao
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Institute of Edible Fungi, Shanghai Academy of Agriculture Science, 1000 Jinqi Rd, Fengxian 201403, Shanghai, China
| | - Shan Jiang
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Institute of Edible Fungi, Shanghai Academy of Agriculture Science, 1000 Jinqi Rd, Fengxian 201403, Shanghai, China
| | - Hongyu Chen
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Institute of Edible Fungi, Shanghai Academy of Agriculture Science, 1000 Jinqi Rd, Fengxian 201403, Shanghai, China
| | - Junjun Shang
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Institute of Edible Fungi, Shanghai Academy of Agriculture Science, 1000 Jinqi Rd, Fengxian 201403, Shanghai, China
| | - Xiaojun Wang
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Institute of Edible Fungi, Shanghai Academy of Agriculture Science, 1000 Jinqi Rd, Fengxian 201403, Shanghai, China
| | - Hnin Hnin Yu
- Microbiology Laboratory, Botany Department, University of Mandalay, 73 & 41 Street, Maharaungmyay Township, Mandalay Division, Myanmar
| | - Gen Zou
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Institute of Edible Fungi, Shanghai Academy of Agriculture Science, 1000 Jinqi Rd, Fengxian 201403, Shanghai, China.
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Wang L, Xie Y, Chang J, Wang J, Liu H, Shi M, Zhong Y. A novel sucrose-inducible expression system and its application for production of biomass-degrading enzymes in Aspergillus niger. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:23. [PMID: 36782304 PMCID: PMC9926565 DOI: 10.1186/s13068-023-02274-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Accepted: 01/30/2023] [Indexed: 02/15/2023]
Abstract
BACKGROUND Filamentous fungi are extensively exploited as important enzyme producers due to the superior secretory capability. However, the complexity of their secretomes greatly impairs the titer and purity of heterologous enzymes. Meanwhile, high-efficient evaluation and production of bulk enzymes, such as biomass-degrading enzymes, necessitate constructing powerful expression systems for bio-refinery applications. RESULTS A novel sucrose-inducible expression system based on the host strain Aspergillus niger ATCC 20611 and the β-fructofuranosidase promoter (PfopA) was constructed. A. niger ATCC 20611 preferentially utilized sucrose for rapid growth and β-fructofuranosidase production. Its secretory background was relatively clean because β-fructofuranosidase, the key enzyme responsible for sucrose utilization, was essentially not secreted into the medium and the extracellular protease activity was low. Furthermore, the PfopA promoter showed a sucrose concentration-dependent induction pattern and was not subject to glucose repression. Moreover, the strength of PfopA was 7.68-fold higher than that of the commonly used glyceraldehyde-3-phosphate dehydrogenase promoter (PgpdA) with enhanced green fluorescence protein (EGFP) as a reporter. Thus, A. niger ATCC 20611 coupled with the PfopA promoter was used as an expression system to express a β-glucosidase gene (bgla) from A. niger C112, allowing the production of β-glucosidase at a titer of 17.84 U/mL. The crude β-glucosidase preparation could remarkably improve glucose yield in the saccharification of pretreated corncob residues when added to the cellulase mixture of Trichoderma reesei QM9414. The efficacy of this expression system was further demonstrated by co-expressing the T. reesei-derived chitinase Chi46 and β-N-acetylglucosaminidase Nag1 to obtain an efficient chitin-degrading enzyme cocktail, which could achieve the production of N-acetyl-D-glucosamine from colloidal chitin with a conversion ratio of 91.83%. Besides, the purity of the above-secreted biomass-degrading enzymes in the crude culture supernatant was over 86%. CONCLUSIONS This PfopA-driven expression system expands the genetic toolbox of A. niger and broadens the application field of the traditional fructo-oligosaccharides-producing strain A. niger ATCC 20611, advancing it to become a high-performing enzyme-producing cell factory. In particular, the sucrose-inducible expression system possessed the capacity to produce biomass-degrading enzymes at a high level and evade endogenous protein interference, providing a potential purification-free enzyme production platform for bio-refinery applications.
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Affiliation(s)
- Lu Wang
- grid.27255.370000 0004 1761 1174State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237 People’s Republic of China
| | - Yijia Xie
- Qingdao Academy, Qingdao, 266111 People’s Republic of China
| | - Jingjing Chang
- grid.27255.370000 0004 1761 1174State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237 People’s Republic of China
| | - Juan Wang
- grid.27255.370000 0004 1761 1174State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237 People’s Republic of China
| | - Hong Liu
- grid.27255.370000 0004 1761 1174State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237 People’s Republic of China
| | - Mei Shi
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China.
| | - Yaohua Zhong
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China.
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Pham HM, Le DT, Le LT, Chu PTM, Tran LH, Pham TT, Nguyen HM, Luu TT, Hoang H, Chu HH. A highly quality genome sequence of Penicillium oxalicum species isolated from the root of Ixora chinensis in Vietnam. G3 (BETHESDA, MD.) 2022; 13:6858938. [PMID: 36454044 PMCID: PMC9911084 DOI: 10.1093/g3journal/jkac300] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 11/02/2022] [Accepted: 11/08/2022] [Indexed: 12/02/2022]
Abstract
Penicillium oxalicum has been reported as a multienzyme-producing fungus and is widely used in industry due to great potential for cellulase release. Until now, there are only 10 available genome assemblies of P. oxalicum species deposited in the GenBank database. In this study, the genome of the I1R1 strain isolated from the root of Ixora chinensis was completely sequenced by Pacbio Sequel sequencing technology, assembled into 8 chromosomes with the genome size of 30.8 Mb, as well as a mitogenome of 26 kb. The structural and functional analyses of the I1R1 genome revealed gene model annotations encoding an enzyme set involved in significant metabolic processes, along with cytochrome P450s and secondary metabolite biosynthesis. The comparative analysis of the P. oxalicum species based on orthology and gene family duplications indicated their large and closed pan-genome of 9,500 orthologous groups. This is valuable data for future phylogenetic and population genomics studies.
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Affiliation(s)
- Huong Mai Pham
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi 10072, Vietnam
| | - Dung Thi Le
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi 10072, Vietnam
| | - Lam Tung Le
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi 10072, Vietnam
| | - Phuong Thi Minh Chu
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi 10072, Vietnam
| | - Linh Huyen Tran
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi 10072, Vietnam
| | - Tung Thanh Pham
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi 10072, Vietnam
| | - Hung Mau Nguyen
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi 10072, Vietnam
| | - Tien Thuy Luu
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi 10072, Vietnam
| | - Ha Hoang
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Hanoi 10072, Vietnam
| | - Hoang Ha Chu
- Corresponding authors: Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay District, Hanoi 10072, Vietnam.
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Wang H, Pang AP, Wang W, Li B, Li C, Wu FG, Lin F. Discovery of ER-localized sugar transporters for cellulase production with lac1 being essential. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:132. [PMID: 36443855 PMCID: PMC9706901 DOI: 10.1186/s13068-022-02230-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 11/12/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND In the process of cellulose hydrolysis, carbohydrate hydrolysates are transported into cells through membrane transporters, and then affect the expression of cellulase-encoding genes. Sugar transporters play a crucial role in cellulase production in lignocellulolytic fungi, of which relatively few have been functionally validated to date and are all reported to be on cell membrane. RESULT Through transcriptome analysis and qRT-PCR, three putative MFS sugar transporters GST, MFS, and LAC1 were found to display significantly higher mRNA levels in T. reesei grown on cellulose than on glucose. The individual deletion of these three genes compromised cellulase production and delayed sugar absorption by 24 h in T. reesei. Nevertheless, they transported pretty low level of sugars, including galactose, lactose, and mannose, and did not transport glucose, when expressed in yeast system. Meanwhile, all three transporters were unexpectedly found to be intracellular, being located in endoplasmic reticulum (ER). Particularly, the knockout of lac1 almost abolished cellulase production, and significantly inhibited biomass generation regardless of sugar types, indicating that lac1 is essential for cellulase production and biomass formation. The absence of lac1 upregulated genes involved in ribosome biogenesis, while downregulated genes in cellulase production, protein processing in ER (particularly protein glycosylation), and lipid biosynthesis. The inhibition of lac1 deletion on the transcriptional levels of genes related to cellulase biosynthesis was restored after 72 h, but the cellulase production was still inhibited, indicating lac1 might pose a post-transcription regulation on cellulase production that are independent on the known cellulase regulation mediated by CRT1 and XYR1. CONCLUSION For the first time, intracellular sugar transporters (mfs, gst, and lac1) facilitating cellulase production were identified, which was distributed in ER. Their sugar transporting ability was very weak, indicating that they might be related to sugar utilization inside cells rather than the cellular sugar uptake. More importantly, sugar transporter lac1 is first found to be essential for cellulase production and biomass formation by affecting protein processing in ER (particularly protein glycosylation) and lipid biosynthesis. The effect of LAC1 on cellulase production seems to be post-transcriptional at late stage of cellulase production, independent on the well-known cellulase regulation mediated by CRT1 and XYR1. These findings improve the understanding of intracellular sugar transporters in fungi and their important role in cellulase synthesis.
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Affiliation(s)
- Haiyan Wang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Ai-Ping Pang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Wei Wang
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Bingzhi Li
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Chengcheng Li
- School of Light Ind. & Food Sci. and Joint International Research Lab of Lignocellulosic Functional Materials, Nanjing Forestry University, Nanjing, 210037, China
| | - Fu-Gen Wu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Fengming Lin
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China.
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Corrêa TLR, Román EKB, da Silva Cassoli J, dos Santos LV, Pereira GAG. Secretome analysis of Trichoderma reesei RUT-C30 and Penicillium oxalicum reveals their synergic potential to deconstruct sugarcane and energy cane biomasses. Microbiol Res 2022; 260:127017. [DOI: 10.1016/j.micres.2022.127017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 02/18/2022] [Accepted: 03/29/2022] [Indexed: 11/28/2022]
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Promoter regulation and genetic engineering strategies for enhanced cellulase expression in Trichoderma reesei. Microbiol Res 2022; 259:127011. [DOI: 10.1016/j.micres.2022.127011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 03/15/2022] [Accepted: 03/16/2022] [Indexed: 01/18/2023]
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10
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Wang Y, Liu R, Liu H, Li X, Shen L, Zhang W, Song X, Liu W, Liu X, Zhong Y. Development of a powerful synthetic hybrid promoter to improve the cellulase system of Trichoderma reesei for efficient saccharification of corncob residues. Microb Cell Fact 2022; 21:5. [PMID: 34983541 PMCID: PMC8725555 DOI: 10.1186/s12934-021-01727-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 12/17/2021] [Indexed: 02/07/2023] Open
Abstract
Background The filamentous fungus Trichoderma reesei is a widely used workhorse for cellulase production in industry due to its prominent secretion capacity of extracellular cellulolytic enzymes. However, some key components are not always sufficient in this cellulase cocktail, making the conversion of cellulose-based biomass costly on the industrial scale. Development of strong and efficient promoters would enable cellulase cocktail to be optimized for bioconversion of biomass. Results In this study, a synthetic hybrid promoter was constructed and applied to optimize the cellulolytic system of T. reesei for efficient saccharification towards corncob residues. Firstly, a series of 5’ truncated promoters in different lengths were established based on the strong constitutive promoter Pcdna1. The strongest promoter amongst them was Pcdna1-3 (− 640 to − 1 bp upstream of the translation initiation codon ATG), exhibiting a 1.4-fold higher activity than that of the native cdna1 promoter. Meanwhile, the activation region (− 821 to − 622 bp upstream of the translation initiation codon ATG and devoid of the Cre1-binding sites) of the strong inducible promoter Pcbh1 was cloned and identified to be an amplifier in initiating gene expression. Finally, this activation region was fused to the strongest promoter Pcdna1-3, generating the novel synthetic hybrid promoter Pcc. This engineered promoter Pcc drove strong gene expression by displaying 1.6- and 1.8-fold stronger fluorescence intensity than Pcbh1 and Pcdna1 under the inducible condition using egfp as the reporter gene, respectively. Furthermore, Pcc was applied to overexpress the Aspergillus niger β-glucosidase BGLA coding gene bglA and the native endoglucanase EG2 coding gene eg2, achieving 43.5-fold BGL activity and 1.2-fold EG activity increase, respectively. Ultimately, to overcome the defects of the native cellulase system in T. reesei, the bglA and eg2 were co-overexpressed under the control of Pcc promoter. The bglA-eg2 double expression strain QPEB70 exhibited a 178% increase in total cellulase activity, whose cellulase system displayed 2.3- and 2.4-fold higher saccharification efficiency towards acid-pretreated and delignified corncob residues than the parental strain, respectively. Conclusions The synthetic hybrid promoter Pcc was generated and employed to improve the cellulase system of T. reesei by expressing specific components. Therefore, construction of synthetic hybrid promoters would allow particular cellulase genes to be expressed at desired levels, which is a viable strategy to optimize the cellulolytic enzyme system for efficient biomass bioconversion. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-021-01727-8.
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Affiliation(s)
- Yifan Wang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Ruiyan Liu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Hong Liu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Xihai Li
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Linjing Shen
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Weican Zhang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Xin Song
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Xiangmei Liu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China.
| | - Yaohua Zhong
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China.
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11
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Bhardwaj N, Kumar B, Agrawal K, Verma P. Current perspective on production and applications of microbial cellulases: a review. BIORESOUR BIOPROCESS 2021; 8:95. [PMID: 38650192 PMCID: PMC10992179 DOI: 10.1186/s40643-021-00447-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 09/21/2021] [Indexed: 12/27/2022] Open
Abstract
The potential of cellulolytic enzymes has been widely studied and explored for bioconversion processes and plays a key role in various industrial applications. Cellulase, a key enzyme for cellulose-rich waste feedstock-based biorefinery, has increasing demand in various industries, e.g., paper and pulp, juice clarification, etc. Also, there has been constant progress in developing new strategies to enhance its production, such as the application of waste feedstock as the substrate for the production of individual or enzyme cocktails, process parameters control, and genetic manipulations for enzyme production with enhanced yield, efficiency, and specificity. Further, an insight into immobilization techniques has also been presented for improved reusability of cellulase, a critical factor that controls the cost of the enzyme at an industrial scale. In addition, the review also gives an insight into the status of the significant application of cellulase in the industrial sector, with its techno-economic analysis for future applications. The present review gives a complete overview of current perspectives on the production of microbial cellulases as a promising tool to develop a sustainable and greener concept for industrial applications.
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Affiliation(s)
- Nisha Bhardwaj
- Bioprocess and Bioenergy Laboratory, Department of Microbiology, Central University of Rajasthan, NH-8, Bandarsindri, Kishangarh, Ajmer, Rajasthan, 305817, India
- Department of Chemical Engineering, Institute of Chemical Technology, Nathalal Parekh Marg, Matunga, Mumbai, Maharashtra, 400019, India
| | - Bikash Kumar
- Bioprocess and Bioenergy Laboratory, Department of Microbiology, Central University of Rajasthan, NH-8, Bandarsindri, Kishangarh, Ajmer, Rajasthan, 305817, India
| | - Komal Agrawal
- Bioprocess and Bioenergy Laboratory, Department of Microbiology, Central University of Rajasthan, NH-8, Bandarsindri, Kishangarh, Ajmer, Rajasthan, 305817, India
| | - Pradeep Verma
- Bioprocess and Bioenergy Laboratory, Department of Microbiology, Central University of Rajasthan, NH-8, Bandarsindri, Kishangarh, Ajmer, Rajasthan, 305817, India.
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12
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Borne R, Vita N, Franche N, Tardif C, Perret S, Fierobe HP. Engineering of a new Escherichia coli strain efficiently metabolizing cellobiose with promising perspectives for plant biomass-based application design. Metab Eng Commun 2021; 12:e00157. [PMID: 33457204 PMCID: PMC7797564 DOI: 10.1016/j.mec.2020.e00157] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 11/24/2020] [Accepted: 12/14/2020] [Indexed: 11/30/2022] Open
Abstract
The necessity to decrease our fossil energy dependence requests bioprocesses based on biomass degradation. Cellobiose is the main product released by cellulases when acting on the major plant cell wall polysaccharide constituent, the cellulose. Escherichia coli, one of the most common model organisms for the academy and the industry, is unable to metabolize this disaccharide. In this context, the remodeling of E. coli to catabolize cellobiose should thus constitute an important progress for the design of such applications. Here, we developed a robust E. coli strain able to metabolize cellobiose by integration of a small set of modifications in its genome. Contrary to previous studies that use adaptative evolution to achieve some growth on this sugar by reactivating E. coli cryptic operons coding for cellobiose metabolism, we identified easily insertable modifications impacting the cellobiose import (expression of a gene coding a truncated variant of the maltoporin LamB, modification of the expression of lacY encoding the lactose permease) and its intracellular degradation (genomic insertion of a gene encoding either a cytosolic β-glucosidase or a cellobiose phosphorylase). Taken together, our results provide an easily transferable set of mutations that confers to E. coli an efficient growth phenotype on cellobiose (doubling time of 2.2 h in aerobiosis) without any prior adaptation.
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Affiliation(s)
| | | | | | - Chantal Tardif
- Aix-Marseille Université, CNRS, UMR7283, 31 ch. Joseph Aiguier, F-13402, Marseille, France
| | - Stéphanie Perret
- Aix-Marseille Université, CNRS, UMR7283, 31 ch. Joseph Aiguier, F-13402, Marseille, France
| | - Henri-Pierre Fierobe
- Aix-Marseille Université, CNRS, UMR7283, 31 ch. Joseph Aiguier, F-13402, Marseille, France
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13
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Waghmare PR, Waghmare PP, Gao L, Sun W, Qin Y, Liu G, Qu Y. Efficient Constitutive Expression of Cellulolytic Enzymes in Penicillium oxalicum for Improved Efficiency of Lignocellulose Degradation. J Microbiol Biotechnol 2021; 31:740-746. [PMID: 33746194 PMCID: PMC9705867 DOI: 10.4014/jmb.2101.01003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 03/05/2021] [Accepted: 03/10/2021] [Indexed: 12/15/2022]
Abstract
Efficient cellulolytic enzyme production is important for the development of lignocellulose-degrading enzyme mixtures. However, purification of cellulases from their native hosts is time- and labor-consuming. In this study, a constitutive expression system was developed in Penicillium oxalicum for the secreted production of proteins. Using a constitutive polyubiquitin gene promoter and cultivating with glucose as the sole carbon source, nine cellulolytic enzymes of different origins with relatively high purity were produced within 48 h. When supplemented to a commercial cellulase preparation, cellobiohydrolase I from P. funiculosum and cellobiohydrolase II from Talaromyces verruculosus showed remarkable enhancing effects on the hydrolysis of steam-exploded corn stover. Additionally, a synergistic effect was observed for these two cellobiohydrolases during the hydrolysis. Taken together, the constitutive expression system provides a convenient tool for the production of cellulolytic enzymes, which is expected to be useful in the development of highly efficient lignocellulose-degrading enzyme mixtures.
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Affiliation(s)
| | | | - Liwei Gao
- State Key Laboratory of Microbial Technology, Shandong University, Shandong 266237, P. R. China
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Shandong 266101, P. R. China
| | - Wan Sun
- State Key Laboratory of Microbial Technology, Shandong University, Shandong 266237, P. R. China
- National Glycoengineering Research Center, Shandong University, Shandong 266237, P. R. China
| | - Yuqi Qin
- State Key Laboratory of Microbial Technology, Shandong University, Shandong 266237, P. R. China
- National Glycoengineering Research Center, Shandong University, Shandong 266237, P. R. China
| | - Guodong Liu
- State Key Laboratory of Microbial Technology, Shandong University, Shandong 266237, P. R. China
- National Glycoengineering Research Center, Shandong University, Shandong 266237, P. R. China
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, Shandong University, Shandong 266237, P. R. China
- National Glycoengineering Research Center, Shandong University, Shandong 266237, P. R. China
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14
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Abstract
Trichoderma reesei has 11 putative β-glucosidases in its genome, playing key parts in the induction and production of cellulase. Nevertheless, the reason why the T. reesei genome encodes so many β-glucosidases and the distinct role each β-glucosidase plays in cellulase production remain unknown. In the present study, the cellular function and distribution of 10 known β-glucosidases (CEL3B, CEL3E, CEL3F, CEL3H, CEL3J, CEL1A, CEL3C, CEL1B, CEL3G, and CEL3D) were explored in T. reesei, leaving out BGL1 (CEL3A), which has been well investigated. We found that the overexpression of cel3b or cel3g significantly enhanced extracellular β-glucosidase production, whereas the overexpression of cel1b severely inhibited cellulase production by cellulose, resulting in nearly no growth of T. reesei. Four types of cellular distribution patterns were observed for β-glucosidases in T. reesei: (i) CEL3B, CEL3E, CEL3F, and CEL3G forming clearly separated protein secretion vesicles in the cytoplasm; (ii) CEL3H and CEL3J diffusing the whole endomembrane as well as the cell membrane with protein aggregation, like a reticular network; (iii) CEL1A and CEL3D in vacuoles; (iv) and CEL3C in the nucleus. β-glucosidases CEL1A, CEL3B, CEL3E, CEL3F, CEL3G, CEL3H, and CEL3J were identified as extracellular, CEL3C and CEL3D as intracellular, and CEL1B as unknown. The extracellular β-glucosidases CEL3B, CEL3E, CEL3F, CEL3H, and CEL3G were secreted through a tip-directed conventional secretion pathway, and CEL1A, via a vacuole-mediated pathway that was achieved without any signal peptide, while CEL3J was secreted via an unconventional protein pathway bypassing the endoplasmic reticulum (ER) and Golgi.
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15
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Unconventional β-Glucosidases: A Promising Biocatalyst for Industrial Biotechnology. Appl Biochem Biotechnol 2021; 193:2993-3016. [PMID: 33871765 DOI: 10.1007/s12010-021-03568-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 04/08/2021] [Indexed: 10/21/2022]
Abstract
β-Glucosidases primarily catalyze removal of terminal glucosyl residues from a variety of glucoconjugates and also perform transglycosylation and reverse hydrolysis. These catalytic properties can be readily exploited for degradation of lignocellulosic biomass as well as for pharmaceutical, food and flavor industries. β-Glucosidases have been either isolated in the native form from the producer organism or recombinantly expressed and gaged for their biochemical properties and substrate specificities. Although almond and Aspergillus niger have been instantly recognizable sources of β-glucosidases utilized for various applications, an intricate pool of novel β-glucosidases from different sources can provide their potent replacements. Moreover, one can envisage the better efficacy of these novel candidates in biofuel and biorefinery industries facilitating efficient degradation of biomass. This article reviews properties of the novel β-glucosidases such as glucose tolerance and activation, substrate specificity, and thermostability which can be useful for their applications in lignocellulose degradation, food industry, and pharmaceutical industry in comparison with the β-glucosidases from the conventional sources. Such β-glucosidases have potential for encouraging white biotechnology.
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16
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Pang AP, Wang H, Zhang F, Hu X, Wu FG, Zhou Z, Wang W, Lu Z, Lin F. High-dose rapamycin exerts a temporary impact on T. reesei RUT-C30 through gene trFKBP12. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:77. [PMID: 33771193 PMCID: PMC8004424 DOI: 10.1186/s13068-021-01926-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 03/11/2021] [Indexed: 05/15/2023]
Abstract
BACKGROUND Knowledge with respect to regulatory systems for cellulase production is prerequisite for exploitation of such regulatory networks to increase cellulase production, improve fermentation efficiency and reduce the relevant production cost. The target of rapamycin (TOR) signaling pathway is considered as a central signaling hub coordinating eukaryotic cell growth and metabolism with environmental inputs. However, how and to what extent the TOR signaling pathway and rapamycin are involved in cellulase production remain elusive. RESULT At the early fermentation stage, high-dose rapamycin (100 μM) caused a temporary inhibition effect on cellulase production, cell growth and sporulation of Trichoderma reesei RUT-C30 independently of the carbon sources, and specifically caused a tentative morphology defect in RUT-C30 grown on cellulose. On the contrary, the lipid content of T. reesei RUT-C30 was not affected by rapamycin. Accordingly, the transcriptional levels of genes involved in the cellulase production were downregulated notably with the addition of rapamycin. Although the mRNA levels of the putative rapamycin receptor trFKBP12 was upregulated significantly by rapamycin, gene trTOR (the downstream effector of the rapamycin-FKBP12 complex) and genes associated with the TOR signaling pathways were not changed markedly. With the deletion of gene trFKBP12, there is no impact of rapamycin on cellulase production, indicating that trFKBP12 mediates the observed temporary inhibition effect of rapamycin. CONCLUSION Our study shows for the first time that only high-concentration rapamycin induced a transient impact on T. reesei RUT-C30 at its early cultivation stage, demonstrating T. reesei RUT-C30 is highly resistant to rapamycin, probably due to that trTOR and its related signaling pathways were not that sensitive to rapamycin. This temporary influence of rapamycin was facilitated by gene trFKBP12. These findings add to our knowledge on the roles of rapamycin and the TOR signaling pathways play in T. reesei.
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Affiliation(s)
- Ai-Ping Pang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Haiyan Wang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Funing Zhang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Xin Hu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Fu-Gen Wu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Zhihua Zhou
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Wei Wang
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Zuhong Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Fengming Lin
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
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17
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Tingley JP, Low KE, Xing X, Abbott DW. Combined whole cell wall analysis and streamlined in silico carbohydrate-active enzyme discovery to improve biocatalytic conversion of agricultural crop residues. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:16. [PMID: 33422151 PMCID: PMC7797155 DOI: 10.1186/s13068-020-01869-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 12/24/2020] [Indexed: 05/08/2023]
Abstract
The production of biofuels as an efficient source of renewable energy has received considerable attention due to increasing energy demands and regulatory incentives to reduce greenhouse gas emissions. Second-generation biofuel feedstocks, including agricultural crop residues generated on-farm during annual harvests, are abundant, inexpensive, and sustainable. Unlike first-generation feedstocks, which are enriched in easily fermentable carbohydrates, crop residue cell walls are highly resistant to saccharification, fermentation, and valorization. Crop residues contain recalcitrant polysaccharides, including cellulose, hemicelluloses, pectins, and lignin and lignin-carbohydrate complexes. In addition, their cell walls can vary in linkage structure and monosaccharide composition between plant sources. Characterization of total cell wall structure, including high-resolution analyses of saccharide composition, linkage, and complex structures using chromatography-based methods, nuclear magnetic resonance, -omics, and antibody glycome profiling, provides critical insight into the fine chemistry of feedstock cell walls. Furthermore, improving both the catalytic potential of microbial communities that populate biodigester reactors and the efficiency of pre-treatments used in bioethanol production may improve bioconversion rates and yields. Toward this end, knowledge and characterization of carbohydrate-active enzymes (CAZymes) involved in dynamic biomass deconstruction is pivotal. Here we overview the use of common "-omics"-based methods for the study of lignocellulose-metabolizing communities and microorganisms, as well as methods for annotation and discovery of CAZymes, and accurate prediction of CAZyme function. Emerging approaches for analysis of large datasets, including metagenome-assembled genomes, are also discussed. Using complementary glycomic and meta-omic methods to characterize agricultural residues and the microbial communities that digest them provides promising streams of research to maximize value and energy extraction from crop waste streams.
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Affiliation(s)
- Jeffrey P Tingley
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, 5403-1st Avenue South, Lethbridge, AB, T1J 4B1, Canada
- Department of Biochemistry, University of Lethbridge, Lethbridge, AB, T1K 6T5, Canada
| | - Kristin E Low
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, 5403-1st Avenue South, Lethbridge, AB, T1J 4B1, Canada
| | - Xiaohui Xing
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, 5403-1st Avenue South, Lethbridge, AB, T1J 4B1, Canada
| | - D Wade Abbott
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, 5403-1st Avenue South, Lethbridge, AB, T1J 4B1, Canada.
- Department of Biochemistry, University of Lethbridge, Lethbridge, AB, T1K 6T5, Canada.
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18
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Zou G, Bao D, Wang Y, Zhou S, Xiao M, Yang Z, Wang Y, Zhou Z. Alleviating product inhibition of Trichoderma reesei cellulase complex with a product-activated mushroom endoglucanase. BIORESOURCE TECHNOLOGY 2021; 319:124119. [PMID: 32957048 DOI: 10.1016/j.biortech.2020.124119] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/08/2020] [Accepted: 09/09/2020] [Indexed: 06/11/2023]
Abstract
Product inhibition of cellulase is a challenging issue in industrial processes. Here, we introduced a product-activated mushroom cellulase, PaCel3A from Polyporus arcularius, into Trichoderma reesei. The filter paper activity, carboxymethyl cellulase activity, and saccharification efficiency (substrate: pretreated rice straw, PRS) of transformants increased significantly with this enzyme (by 18.4-26.8%, 13.8-22.8%, and 17.0%, respectively). A mutant of PaCel3A, PaCel3AM, obtained based on B-factor analysis, saturated mutagenesis, and residual activity assay, showed improved thermostability. The PRS saccharification efficiency using the cellulase complex from T. reesei transformants overexpressing pacel3am increased by 56.4%-63.0%. In addition, the T. reesei cellulase complex obtained by adding the purified recombinant PaCel3AM from T. reesei (rCel3aM-tr) to hydrolyze PRS resulted in increased reducing sugar yields at all sampling points, outperforming the cellulase complexes without rCel3aM-tr. These results suggest that introducing product-activated cellulase genes is a simple and feasible method to alleviate the product inhibition of cellulase.
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Affiliation(s)
- Gen Zou
- Shanghai Key Laboratory of Agricultural Genetics and Breeding; Institute of Edible Fungi, Shanghai Academy of Agriculture Science, 1000 Jinqi Rd, Fengxian 201403, Shanghai, China; CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Science, Fenglin Rd 300, Shanghai 200032, China.
| | - Dapeng Bao
- Shanghai Key Laboratory of Agricultural Genetics and Breeding; Institute of Edible Fungi, Shanghai Academy of Agriculture Science, 1000 Jinqi Rd, Fengxian 201403, Shanghai, China.
| | - Ying Wang
- Shanghai Key Laboratory of Agricultural Genetics and Breeding; Institute of Edible Fungi, Shanghai Academy of Agriculture Science, 1000 Jinqi Rd, Fengxian 201403, Shanghai, China
| | - Sichi Zhou
- Shanghai Key Laboratory of Agricultural Genetics and Breeding; Institute of Edible Fungi, Shanghai Academy of Agriculture Science, 1000 Jinqi Rd, Fengxian 201403, Shanghai, China
| | - Meili Xiao
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Science, Fenglin Rd 300, Shanghai 200032, China.
| | - Zhanshan Yang
- Shanghai Key Laboratory of Agricultural Genetics and Breeding; Institute of Edible Fungi, Shanghai Academy of Agriculture Science, 1000 Jinqi Rd, Fengxian 201403, Shanghai, China
| | - Yinmei Wang
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Science, Fenglin Rd 300, Shanghai 200032, China.
| | - Zhihua Zhou
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Science, Fenglin Rd 300, Shanghai 200032, China.
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19
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Cai L, Xu S, Lu T, Lin D, Yao S. Salt-tolerant mechanism of marine Aspergillus niger cellulase cocktail and improvement of its activity. Chin J Chem Eng 2020. [DOI: 10.1016/j.cjche.2019.11.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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20
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Carreras-Villaseñor N, Rico-Ruiz JG, Chávez Montes RA, Yong-Villalobos L, López-Hernández JF, Martínez-Hernández P, Herrera-Estrella L, Herrera-Estrella A, López-Arredondo D. Assessment of the ptxD gene as a growth and selective marker in Trichoderma atroviride using Pccg6, a novel constitutive promoter. Microb Cell Fact 2020; 19:69. [PMID: 32188455 PMCID: PMC7081547 DOI: 10.1186/s12934-020-01326-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 03/08/2020] [Indexed: 01/08/2023] Open
Abstract
Background Trichoderma species are among the most effective cell factories to produce recombinant proteins, whose productivity relies on the molecular toolkit and promoters available for the expression of the target protein. Although inducible promoter systems have been developed for producing recombinant proteins in Trichoderma, constitutive promoters are often a desirable alternative. Constitutive promoters are simple to use, do not require external stimuli or chemical inducers to be activated, and lead to purer enzyme preparations. Moreover, most of the promoters for homologous and heterologous expression reported in Trichoderma have been commonly evaluated by directly assessing production of industrial enzymes, requiring optimization of laborious protocols. Results Here we report the identification of Pccg6, a novel Trichoderma atroviride constitutive promoter, that has similar transcriptional strength as that of the commonly used pki1 promoter. Pccg6 displayed conserved arrangements of transcription factor binding sites between promoter sequences of Trichoderma ccg6 orthologues genes, potentially involved in their regulatory properties. The predicted ccg6-encoded protein potentially belongs to the SPE1/SPI1 protein family and shares high identity with CCG6 orthologue sequences from other fungal species including Trichoderma reesei, Trichoderma virens, Trichoderma asperellum, and to a lesser extent to that of Neurospora crassa. We also report the use of the Pccg6 promoter to drive the expression of PTXD, a phosphite oxidoreductase of bacterial origin, which allowed T. atroviride to utilize phosphite as a sole source of phosphorus. We propose ptxD as a growth reporter gene that allows real-time comparison of the functionality of different promoters by monitoring growth of Trichoderma transgenic lines and enzymatic activity of PTXD. Finally, we show that constitutive expression of ptxD provided T. atroviride a competitive advantage to outgrow bacterial contaminants when supplied with phosphite as a sole source of phosphorus. Conclusions A new constitutive promoter, ccg6, for expression of homologous and heterologous proteins has been identified and tested in T. atroviride to express PTXD, which resulted in an effective and visible phenotype to evaluate transcriptional activity of sequence promoters. Use of PTXD as a growth marker holds great potential for assessing activity of other promoters and for biotechnological applications as a contamination control system.
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Affiliation(s)
- Nohemí Carreras-Villaseñor
- StelaGenomics México, S de RL de CV, Av. Camino Real de Guanajuato s/n, 36821, Irapuato, Guanajuato, Mexico.,Red de Estudios Moleculares Avanzados, Instituto de Ecología A.C, Xalapa, 91070, Mexico
| | - José Guillermo Rico-Ruiz
- StelaGenomics México, S de RL de CV, Av. Camino Real de Guanajuato s/n, 36821, Irapuato, Guanajuato, Mexico.,Laboratorio Nacional de Genómica para la Biodiversidad, Unidad de Genómica Avanzada del Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Km 9.6 carretera Irapuato León, 36500, Irapuato, Guanajuato, Mexico
| | - Ricardo A Chávez Montes
- Institute of Genomics for Crop Abiotic Stress Tolerance, Texas Tech University, Lubbock, TX, 79409, USA
| | - Lenin Yong-Villalobos
- Institute of Genomics for Crop Abiotic Stress Tolerance, Texas Tech University, Lubbock, TX, 79409, USA
| | - José Fabricio López-Hernández
- Laboratorio Nacional de Genómica para la Biodiversidad, Unidad de Genómica Avanzada del Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Km 9.6 carretera Irapuato León, 36500, Irapuato, Guanajuato, Mexico.,Stowers Institute for Medical Research, Kansas City, MO, 64110, USA
| | - Pedro Martínez-Hernández
- Laboratorio Nacional de Genómica para la Biodiversidad, Unidad de Genómica Avanzada del Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Km 9.6 carretera Irapuato León, 36500, Irapuato, Guanajuato, Mexico
| | - Luis Herrera-Estrella
- Laboratorio Nacional de Genómica para la Biodiversidad, Unidad de Genómica Avanzada del Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Km 9.6 carretera Irapuato León, 36500, Irapuato, Guanajuato, Mexico.,Institute of Genomics for Crop Abiotic Stress Tolerance, Texas Tech University, Lubbock, TX, 79409, USA
| | - Alfredo Herrera-Estrella
- Laboratorio Nacional de Genómica para la Biodiversidad, Unidad de Genómica Avanzada del Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Km 9.6 carretera Irapuato León, 36500, Irapuato, Guanajuato, Mexico
| | - Damar López-Arredondo
- StelaGenomics México, S de RL de CV, Av. Camino Real de Guanajuato s/n, 36821, Irapuato, Guanajuato, Mexico. .,Institute of Genomics for Crop Abiotic Stress Tolerance, Texas Tech University, Lubbock, TX, 79409, USA.
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21
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Sun X, Zhang X, Huang H, Wang Y, Tu T, Bai Y, Wang Y, Zhang J, Luo H, Yao B, Su X. Engineering the cbh1 Promoter of Trichoderma reesei for Enhanced Protein Production by Replacing the Binding Sites of a Transcription Repressor ACE1 to Those of the Activators. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:1337-1346. [PMID: 31933359 DOI: 10.1021/acs.jafc.9b05452] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The strong and inducible cbh1 promoter is most widely used to express heterologous proteins, useful in food and feed industries, in Trichoderma reesei. Enhancing its ability to direct transcription provides a general strategy to improve protein production in T. reesei. The cbh1 promoter was engineered by replacing eight binding sites of the transcription repressor ACE1 to those of the activators ACE2, Hap2/3/5, and Xyr1. While changing ACE1 to Hap2/3/5-binding sites completely abolished the transcription ability, replacements with ACE2- and Xyr1-binding sites (designated cbh1pA and cbh1pX promoters, respectively) largely improved the promoter transcription efficiency, as reflected by expression of a reporter gene DsRed. The cbh1pA and cbh1pX promoters were applied to improve secretory expression of a codon-optimized mannanase from Aspergillus niger to 3.6- and 5.0-fold higher, respectively, which has high application potential in feed industry.
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Affiliation(s)
- Xianhua Sun
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Xuhuan Zhang
- Biotechnology Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , People's Republic of China
| | - Huoqing Huang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Yuan Wang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Tao Tu
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Yingguo Bai
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Yaru Wang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Jie Zhang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Huiying Luo
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Bin Yao
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Xiaoyun Su
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
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Gopalakrishnan RM, Manavalan T, Ramesh J, Thangavelu KP, Heese K. Improvement of Saccharification and Delignification Efficiency of Trichoderma reesei Rut-C30 by Genetic Bioengineering. Microorganisms 2020; 8:microorganisms8020159. [PMID: 31979278 PMCID: PMC7074786 DOI: 10.3390/microorganisms8020159] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 01/20/2020] [Accepted: 01/22/2020] [Indexed: 11/16/2022] Open
Abstract
Trichoderma reesei produces various saccharification enzymes required for biomass degradation. However, the lack of an effective lignin-degrading enzyme system reduces the species’ efficiency in producing fermentable sugars and increases the pre-treatment costs for biofuel production. In this study, we heterologously expressed the Ganoderma lucidum RMK1 versatile peroxidase gene (vp1) in the Rut-C30 strain of T. reesei. The expression of purified 6×His-tag–containing recombinant G. lucidum-derived protein (rVP1) was confirmed through western blot, which exhibited a single band with a relative molecular weight of 39 kDa. In saccharification and delignification studies using rice straw, the transformant (tVP7, T. reesei Rut-C30 expressing G. lucidum-derived rVP1) showed significant improvement in the yield of total reducing sugar and delignification, compared with that of the parent T. reesei Rut-C30 strain. Scanning electron microscopy (SEM) of tVP7-treated paddy straw showed extensive degradation of several layers of its surface compared with the parent strain due to the presence of G. lucidum-derived rVP1. Our results suggest that the expression of ligninolytic enzymes in cellulase hyperproducing systems helps to integrate the pre-treatment and saccharification steps that may ultimately reduce the costs of bioethanol production.
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Affiliation(s)
- Raja Mohan Gopalakrishnan
- Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai, Tamil Nadu 600 025, India; (R.M.G.); (T.M.)
| | - Tamilvendan Manavalan
- Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai, Tamil Nadu 600 025, India; (R.M.G.); (T.M.)
| | - Janani Ramesh
- Department of Medical Biochemistry, Dr ALM Postgraduate Institute of Biomedical Sciences, University of Madras, Chennai, Tamil Nadu 600 113, India;
| | - Kalaichelvan Puthupalayam Thangavelu
- Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai, Tamil Nadu 600 025, India; (R.M.G.); (T.M.)
- Correspondence: (K.P.T.); (K.H.)
| | - Klaus Heese
- Graduate School of Biomedical Science and Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133-791, Korea
- Correspondence: (K.P.T.); (K.H.)
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Emerging technologies for the pretreatment of lignocellulosic materials for bio-based products. Appl Microbiol Biotechnol 2019; 104:455-473. [DOI: 10.1007/s00253-019-10158-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/19/2019] [Accepted: 09/24/2019] [Indexed: 10/25/2022]
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24
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Identification of a thermostable fungal lytic polysaccharide monooxygenase and evaluation of its effect on lignocellulosic degradation. Appl Microbiol Biotechnol 2019; 103:5739-5750. [DOI: 10.1007/s00253-019-09928-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 05/22/2019] [Indexed: 11/27/2022]
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25
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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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Zhang F, Bunterngsook B, Li JX, Zhao XQ, Champreda V, Liu CG, Bai FW. Regulation and production of lignocellulolytic enzymes from Trichoderma reesei for biofuels production. ADVANCES IN BIOENERGY 2019. [DOI: 10.1016/bs.aibe.2019.03.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Liu G, Qu Y. Engineering of filamentous fungi for efficient conversion of lignocellulose: Tools, recent advances and prospects. Biotechnol Adv 2018; 37:519-529. [PMID: 30576717 DOI: 10.1016/j.biotechadv.2018.12.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 12/13/2018] [Accepted: 12/14/2018] [Indexed: 01/17/2023]
Abstract
Filamentous fungi, as the main producers of lignocellulolytic enzymes in industry, need to be engineered to improve the economy of large-scale lignocellulose conversion. Investigation of the cellular processes involved in lignocellulolytic enzyme production, as well as optimization of enzyme mixtures for higher hydrolysis efficiency, have provided effective targets for the engineering of lignocellulolytic fungi. Recently, the development of efficient genetic manipulation systems in several lignocellulolytic fungi opens up the possibility of systems engineering of these strains. Here, we review the recent progresses made in the engineering of lignocellulolytic fungi and highlight the research gaps in this area.
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Affiliation(s)
- Guodong Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China; Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China; National Glycoengineering Research Center, Shandong University, Qingdao 266237, China.
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Zou G, Jiang Y, Liu R, Zhu Z, Zhou Z. The putative β-glucosidase BGL3I regulates cellulase induction in Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:314. [PMID: 30473732 PMCID: PMC6240962 DOI: 10.1186/s13068-018-1314-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 11/08/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND The filamentous fungus Trichoderma reesei (anamorph of Hypocrea jecorina) displays increased cellulase expression while growing on inducers such as lactose or cellulose. However, the mechanism of cellulase induction in T. reesei is not yet completely characterized. Here, a protein annotated as β-glucosidase (BGL3I) was found to be involved in cellulase induction in T. reesei. The effects of BGL3I on cellulase production have not yet been fully understood. RESULTS Deletion of the bgl3i gene had no influence on the growth of T. reesei, but significantly increased its cellulase activities. Deletion of bgl3i also resulted in decreased extracellular galactosidase activity, but significantly increased transcription of lactose permeases, which might be involved in lactose transport. Furthermore, deletion of bgl3i enhanced the transcription levels of intracellular β-glucosidases cel1a, cel1b and the regulator xyr1, which are all essential for lactose induction in T. reesei. BGL3I was found to have a relatively high ability to hydrolyze sophorose, which is proposed to be the strongest natural inducer of cellulase synthesis in T. reesei. CONCLUSIONS BGL3I may take part in the complex regulating system of cellulase induction. The deletion of bgl3i offers a new strategy to improve T. reesei strain performance.
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Affiliation(s)
- Gen Zou
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Rd, Shanghai, 200032 China
- Shanghai Key Laboratory of Agricultural Genetics and Breeding; Institute of Edible Fungi, Shanghai Academy of Agriculture Science, 1000 Jinqi Rd, Fengxian, 201403 Shanghai China
| | - Yanping Jiang
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Rd, Shanghai, 200032 China
- Southwest Jiaotong University, Chengdu, 611756 Sichuan China
| | - Rui Liu
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Rd, Shanghai, 200032 China
| | - Zhihua Zhu
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Rd, Shanghai, 200032 China
| | - Zhihua Zhou
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Rd, Shanghai, 200032 China
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29
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Meng QS, Liu CG, Zhao XQ, Bai FW. Engineering Trichoderma reesei Rut-C30 with the overexpression of egl1 at the ace1 locus to relieve repression on cellulase production and to adjust the ratio of cellulolytic enzymes for more efficient hydrolysis of lignocellulosic biomass. J Biotechnol 2018; 285:56-63. [DOI: 10.1016/j.jbiotec.2018.09.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/06/2018] [Accepted: 09/03/2018] [Indexed: 01/25/2023]
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30
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Li C, Lin F, Sun W, Yuan S, Zhou Z, Wu FG, Chen Z. Constitutive hyperproduction of sorbicillinoids in Trichoderma reesei ZC121. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:291. [PMID: 30386428 PMCID: PMC6202828 DOI: 10.1186/s13068-018-1296-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 10/16/2018] [Indexed: 05/28/2023]
Abstract
BACKGROUND In addition to its outstanding cellulase production ability, Trichoderma reesei produces a wide variety of valuable secondary metabolites, the production of which has not received much attention to date. Among them, sorbicillinoids, a large group of hexaketide secondary metabolites derived from polyketides, are drawing a growing interest from researchers because they exhibit a variety of important biological functions, including anticancer, antioxidant, antiviral, and antimicrobial properties. The development of fungi strains with constitutive, hyperproduction of sorbicillinoids is thus desired for future industry application but is not well-studied. Moreover, although T. reesei has been demonstrated to produce sorbicillinoids with the corresponding gene cluster and biosynthesis pathway proposed, the underlying molecular mechanism governing sorbicillinoid biosynthesis remains unknown. RESULTS Recombinant T. reesei ZC121 was constructed from strain RUT-C30 by the insertion of the gene 12121-knockout cassette at the telomere of T. reesei chromosome IV in consideration of the off-target mutagenesis encountered during the unsuccessful deletion of gene 121121. Strain ZC121, when grown on cellulose, showed a sharp reduction of cellulase production, but yet a remarkable enhancement of sorbicillinoids production as compared to strain RUT-C30. The hyperproduction of sorbicillinoids is a constitutive process, independent of culture conditions such as carbon source, light, pH, and temperature. To the best of our knowledge, strain ZC121 displays record sorbicillinoid production levels when grown on both glucose and cellulose. Sorbicillinol and bisvertinolone are the two major sorbicillinoid compounds produced. ZC121 displayed a different morphology and markedly reduced sporulation compared to RUT-C30 but had a similar growth rate and biomass. Transcriptome analysis showed that most genes involved in cellulase production were downregulated significantly in ZC121 grown on cellulose, whereas remarkably all genes in the sorbicillinoid gene cluster were upregulated on both cellulose and glucose. CONCLUSION A constitutive sorbicillinoid-hyperproduction strain T. reesei ZC121 was obtained by off-target mutagenesis, displaying an overwhelming shift from cellulase production to sorbicillinoid production on cellulose, leading to a record for sorbicillinoid production. For the first time, T. reesei degraded cellulose to produce platform chemical compounds other than protein in high yield. We propose that the off-target mutagenesis occurring at the telomere region might cause chromosome remodeling and subsequently alter the cell structure and the global gene expression pattern of strain ZC121, as shown by phenotype profiling and comparative transcriptome analysis of ZC121. Overall, T. reesei ZC121 holds great promise for the industrial production of sorbicillinoids and serves as a good model to explore the regulation mechanism of sorbicillinoids' biosynthesis.
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Affiliation(s)
- Chengcheng Li
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096 China
| | - Fengming Lin
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096 China
- Nanjing, China
| | - Wei Sun
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096 China
| | - Shaoxun Yuan
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096 China
| | - Zhihua Zhou
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032 China
| | - Fu-Gen Wu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096 China
| | - Zhan Chen
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI 48109 USA
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Fang X, Qu Y. Metabolic Engineering of Fungal Strains for Efficient Production of Cellulolytic Enzymes. FUNGAL CELLULOLYTIC ENZYMES 2018:27-41. [PMCID: PMC7120360 DOI: 10.1007/978-981-13-0749-2_2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Filamentous fungi are widely used for production of cellulase and other cellulolytic enzymes. Metabolic engineering of filamentous fungal strains has been applied to improve enzyme production, and rapid progress has been made in the recent years. In this chapter, genetic tools and methods to develop superior enzyme producers are summarized, which includes establishment of genetic modification systems, selection and redesign of promoters, and metabolic engineering using either native transcription factors or artificial ones. In addition, enhancement of cellulase production through morphology engineering was also discussed. Emerging tools including CRISPR-Cas9-based genome editing and synthetic biology are highlighted, which are speeding up mechanisms elucidation and strain development, and will further facilitate economic cellulolytic enzyme production.
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Affiliation(s)
- Xu Fang
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, Shandong China
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, Shandong China
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32
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Xia Y, Yang L, Xia L. High-level production of a fungal β-glucosidase with application potentials in the cost-effective production of Trichoderma reesei cellulase. Process Biochem 2018. [DOI: 10.1016/j.procbio.2018.03.031] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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33
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Evaluation and Optimization of Organic Acid Pretreatment of Cotton Gin Waste for Enzymatic Hydrolysis and Bioethanol Production. Appl Biochem Biotechnol 2018; 186:1047-1060. [DOI: 10.1007/s12010-018-2790-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 05/15/2018] [Indexed: 10/14/2022]
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34
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Li YH, Zhang XY, Zhang F, Peng LC, Zhang DB, Kondo A, Bai FW, Zhao XQ. Optimization of cellulolytic enzyme components through engineering Trichoderma reesei and on-site fermentation using the soluble inducer for cellulosic ethanol production from corn stover. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:49. [PMID: 29483942 PMCID: PMC5824536 DOI: 10.1186/s13068-018-1048-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 02/12/2018] [Indexed: 05/05/2023]
Abstract
BACKGROUND Cellulolytic enzymes produced by Trichoderma reesei are widely studied for biomass bioconversion, and enzymatic components vary depending on different inducers. In our previous studies, a mixture of glucose and disaccharide (MGD) was developed and used to induce cellulase production. However, the enzymatic profile induced by MGD is still not defined, and further optimization of the enzyme cocktail is also required for efficient ethanol production from lignocellulosic biomass. RESULTS In this study, cellulolytic enzymes produced by T. reesei Rut C30 using MGD and alkali-pretreated corn stover (APCS) as inducer were compared. Cellular secretome in response to each inducer was analyzed, which revealed a similar enzyme profile. However, significant difference in the content of cellulases and xylanase was detected. Although MGD induction enhanced β-glucosidase production, its activity was still not sufficient for biomass hydrolysis. To overcome such a disadvantage, aabgl1 encoding β-glucosidase in Aspergillus aculeatus was heterologously expressed in T. reesei Rut C30 under the control of the pdc1 promoter. The recombinant T. reesei PB-3 strain showed an improved β-glucosidase activity of 310 CBU/mL in the fed-batch fermentation, 71-folds higher than that produced by the parent strain. Meanwhile, cellulase activity of 50 FPU/mL was detected. Subsequently, the crude enzyme was applied for hydrolyzing corn stover with a solid loading of 20% through separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation, respectively, for ethanol production. Better performance was observed in the SHF process, through which a total of 119.9 g/L glucose was released within 12 h for concomitant ethanol production of 54.2 g/L. CONCLUSIONS The similar profile of cellulolytic enzymes was detected under the induction of MGD and APCS, but higher amount of cellulases was present in the crude enzyme induced by MGD. However, β-glucosidase activity induced by MGD was not sufficient for hydrolyzing lignocellulosic biomass. High titers of cellulases and β-glucosidase were achieved simultaneously by heterologous expression of aabgl1 in T. reesei and fed-batch fermentation through feeding MGD. We demonstrated that on-site cellulase production by T. reesei PB-3 has a potential for efficient biomass saccharification and ethanol production from lignocellulosic biomass.
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Affiliation(s)
- Yong-Hao Li
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
- Present Address: School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology, Chongqing, 401331 China
| | - Xiao-Yue Zhang
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116023 China
| | - Fei Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Liang-Cai Peng
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Da-Bing Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Akihiko Kondo
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Kobe, 657-8501 Japan
| | - Feng-Wu Bai
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Xin-Qing Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
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Singhania RR, Patel AK, Pandey A, Ganansounou E. Genetic modification: A tool for enhancing beta-glucosidase production for biofuel application. BIORESOURCE TECHNOLOGY 2017; 245:1352-1361. [PMID: 28596076 DOI: 10.1016/j.biortech.2017.05.126] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/17/2017] [Accepted: 05/19/2017] [Indexed: 05/25/2023]
Abstract
Beta-glucosidase (BGL) is a rate-limiting enzyme for cellulose hydrolysis as it acts in the final step of lignocellulosic biomass conversion to convert cellobiose into glucose, the final end product. Most of the fungal strains used for cellulase production are deficient in BGL hence BGL is supplemented into cellulases to have an efficient biomass conversion. Genetic engineering has enabled strain modification to produce BGL optimally with desired properties to be employed for biofuel applications. It has been cloned either directly into the host strains lacking BGL or into another expression system, to be overexpressed so as to be blended into BGL deficient cellulases. In this article, role of genetic engineering to overcome BGL limitations in the cellulase cocktail and its significance for biofuel applications has been critically reviewed.
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Affiliation(s)
- Reeta Rani Singhania
- DBT-IOC Advanced Bio-Energy Research Centre, Indian Oil Corporation; R&D Centre, Sector-13, Faridabad 121007, India
| | - Anil Kumar Patel
- Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu 96822, HI, United States.
| | - Ashok Pandey
- Center of Innovative and Applied Bioprocessing, Sector 81, Knowledge City PO Manauli, SAS Nagar, Mohali 140306, Punjab, India
| | - Edgard Ganansounou
- Bioenergy and Energy Planning Research Group, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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Qian Y, Zhong L, Gao J, Sun N, Wang Y, Sun G, Qu Y, Zhong Y. Production of highly efficient cellulase mixtures by genetically exploiting the potentials of Trichoderma reesei endogenous cellulases for hydrolysis of corncob residues. Microb Cell Fact 2017; 16:207. [PMID: 29162107 PMCID: PMC5696804 DOI: 10.1186/s12934-017-0825-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Accepted: 11/14/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Trichoderma reesei is one of the most important fungi utilized for cellulase production. However, its cellulase system has been proven to be present in suboptimal ratio for deconstruction of lignocellulosic substrates. Although previous enzymatic optimization studies have acquired different types of in vitro synthetic mixtures for efficient lignocellulose hydrolysis, production of in vivo optimized cellulase mixtures by industrial strains remains one of the obstacles to reduce enzyme cost in the biofuels production from lignocellulosic biomass. RESULTS In this study, we used a systematic genetic strategy based on the pyrG marker to overexpress the major cellulase components in a hypercellulolytic T. reesei strain and produce the highly efficient cellulase mixture for saccharification of corncob residues. We found that overexpression of CBH2 exhibited a 32-fold increase in the transcription level and a comparable protein level to CBH1, the most abundant secreted protein in T. reesei, but did not contribute much to the cellulolytic ability. However, when EG2 was overexpressed with a 46-fold increase in the transcription level and a comparable protein level to CBH2, the engineered strain QPE36 showed a 1.5-fold enhancement in the total cellulase activity (up to 5.8 U/mL FPA) and a significant promotion of saccharification efficiency towards differently pretreated corncob residues. To assist the following genetic manipulations, the marker pyrG was successfully excised by homologous recombination based on resistance to 5-FOA. Furthermore, BGL1 was overexpressed in the EG2 overexpression strain QE51 (pyrG-excised) and a 11.6-fold increase in BGL activity was obtained. The EG2-BGL1 double overexpression strain QEB4 displayed a remarkable enhancement of cellulolytic ability on pretreated corncob residues. Especially, a nearly complete cellulose conversion (94.2%) was found for the delignified corncob residues after 48 h enzymatic saccharification. CONCLUSIONS These results demonstrate that genetically exploiting the potentials of T. reesei endogenous cellulases to produce highly efficient cellulase mixtures is a powerful strategy to promote the saccharification efficiency, which will eventually facilitate cost reduction for lignocellulose-based biofuels.
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Affiliation(s)
- Yuanchao Qian
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China
| | - Lixia Zhong
- Shandong Institute for Food and Drug Control, Jinan, 250101, People's Republic of China
| | - Jia Gao
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China
| | - Ningning Sun
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China
| | - Yifan Wang
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China
| | - Guoyong Sun
- Anaesthesiology Department of the Second Hospital of Shandong University, Jinan, 250100, People's Republic of China
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China
| | - Yaohua Zhong
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China.
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Gao J, Qian Y, Wang Y, Qu Y, Zhong Y. Production of the versatile cellulase for cellulose bioconversion and cellulase inducer synthesis by genetic improvement of Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:272. [PMID: 29167702 PMCID: PMC5688634 DOI: 10.1186/s13068-017-0963-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 11/07/2017] [Indexed: 05/05/2023]
Abstract
BACKGROUND The enzymes for efficient hydrolysis of lignocellulosic biomass are a major factor in the development of an economically feasible cellulose bioconversion process. Up to now, low hydrolysis efficiency and high production cost of cellulases remain the significant hurdles in this process. The aim of the present study was to develop a versatile cellulase system with the enhanced hydrolytic efficiency and the ability to synthesize powerful inducers by genetically engineering Trichoderma reesei. RESULTS In our study, we employed a systematic genetic strategy to construct the carbon catabolite-derepressed strain T. reesei SCB18 to produce the cellulase complex that exhibited a strong cellulolytic capacity for biomass saccharification and an extraordinary high β-glucosidase (BGL) activity for cellulase-inducing disaccharides synthesis. We first identified the hypercellulolytic and uracil auxotrophic strain T. reesei SP4 as carbon catabolite repressed, and then deleted the carbon catabolite repressor gene cre1 in the genome. We found that the deletion of cre1 with the selectable marker pyrG led to a 72.6% increase in total cellulase activity, but a slight reduction in saccharification efficiency. To facilitate the following genetic modification, the marker pyrG was successfully removed by homologous recombination based on resistance to 5-FOA. Furthermore, the Aspergillus niger BGLA-encoding gene bglA was overexpressed, and the generated strain T. reesei SCB18 exhibited a 29.8% increase in total cellulase activity and a 51.3-fold enhancement in BGL activity (up to 103.9 IU/mL). We observed that the cellulase system of SCB18 showed significantly higher saccharification efficiency toward differently pretreated corncob residues than the control strains SDC11 and SP4. Moreover, the crude enzyme preparation from SCB18 with high BGL activity possessed strong transglycosylation ability to synthesize β-disaccharides from glucose. The transglycosylation product was finally utilized as the inducer for cellulase production, which provided a 63.0% increase in total cellulase activity compared to the frequently used soluble inducer, lactose. CONCLUSIONS In summary, we constructed a versatile cellulase system in T. reesei for efficient biomass saccharification and powerful cellulase inducer synthesis by combinational genetic manipulation of three distinct types of genes to achieve the customized cellulase production, thus providing a viable strategy for further strain improvement to reduce the cost of biomass-based biofuel production.
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Affiliation(s)
- Jia Gao
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100 People’s Republic of China
| | - Yuanchao Qian
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100 People’s Republic of China
| | - Yifan Wang
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100 People’s Republic of China
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100 People’s Republic of China
| | - Yaohua Zhong
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100 People’s Republic of China
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Druzhinina IS, Kubicek CP. Genetic engineering of Trichoderma reesei cellulases and their production. Microb Biotechnol 2017; 10:1485-1499. [PMID: 28557371 PMCID: PMC5658622 DOI: 10.1111/1751-7915.12726] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 04/11/2017] [Accepted: 04/11/2017] [Indexed: 11/26/2022] Open
Abstract
Lignocellulosic biomass, which mainly consists of cellulose, hemicellulose and lignin, is the most abundant renewable source for production of biofuel and biorefinery products. The industrial use of plant biomass involves mechanical milling or chipping, followed by chemical or physicochemical pretreatment steps to make the material more susceptible to enzymatic hydrolysis. Thereby the cost of enzyme production still presents the major bottleneck, mostly because some of the produced enzymes have low catalytic activity under industrial conditions and/or because the rate of hydrolysis of some enzymes in the secreted enzyme mixture is limiting. Almost all of the lignocellulolytic enzyme cocktails needed for the hydrolysis step are produced by fermentation of the ascomycete Trichoderma reesei (Hypocreales). For this reason, the structure and mechanism of the enzymes involved, the regulation of their expression and the pathways of their formation and secretion have been investigated in T. reesei in considerable details. Several of the findings thereby obtained have been used to improve the formation of the T. reesei cellulases and their properties. In this article, we will review the achievements that have already been made and also show promising fields for further progress.
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Affiliation(s)
- Irina S. Druzhinina
- Microbiology GroupResearch Area Biochemical TechnologyInstitute of Chemical, Environmental and Biological EngineeringTU WienViennaAustria
| | - Christian P. Kubicek
- Microbiology GroupResearch Area Biochemical TechnologyInstitute of Chemical, Environmental and Biological EngineeringTU WienViennaAustria
- Present address:
Steinschötelgasse 7Wien1100Austria
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Matthews CB, Wright C, Kuo A, Colant N, Westoby M, Love JC. Reexamining opportunities for therapeutic protein production in eukaryotic microorganisms. Biotechnol Bioeng 2017; 114:2432-2444. [DOI: 10.1002/bit.26378] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 05/19/2017] [Accepted: 07/03/2017] [Indexed: 12/24/2022]
Affiliation(s)
- Catherine B. Matthews
- Department of Chemical Engineering; Koch Institute for Integrative Cancer Research; Massachusetts Institute of Technology; Cambridge Massachusetts
| | | | - Angel Kuo
- Department of Chemical Engineering; Koch Institute for Integrative Cancer Research; Massachusetts Institute of Technology; Cambridge Massachusetts
| | - Noelle Colant
- Department of Chemical Engineering; Koch Institute for Integrative Cancer Research; Massachusetts Institute of Technology; Cambridge Massachusetts
| | | | - J. Christopher Love
- Department of Chemical Engineering; Koch Institute for Integrative Cancer Research; Massachusetts Institute of Technology; Cambridge Massachusetts
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Manavalan T, Liu R, Zhou Z, Zou G. Optimization of acetyl xylan esterase gene expression in Trichoderma reesei and its application to improve the saccharification efficiency on different biomasses. Process Biochem 2017. [DOI: 10.1016/j.procbio.2017.04.042] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Libardi N, Soccol CR, Góes-Neto A, Oliveira JD, Vandenberghe LPDS. Domestic wastewater as substrate for cellulase production by Trichoderma harzianum. Process Biochem 2017. [DOI: 10.1016/j.procbio.2017.03.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Zhang Z, Wang M, Gao R, Yu X, Chen G. Synergistic effect of thermostable β-glucosidase TN0602 and cellulase on cellulose hydrolysis. 3 Biotech 2017; 7:54. [PMID: 28444598 DOI: 10.1007/s13205-017-0672-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 02/27/2017] [Indexed: 01/22/2023] Open
Abstract
Thermophilic enzymes have many potential benefits in industrial production with increased flexibility related to process configurations. A thermostable β-glucosidase from Thermotoga naphthophila RUK-10 was found to possess catalytic activity for cellobiose hydrolysis with a high potential for application in biomass conversion. The aggregation of cellobiose often has an inhibitory effect on cellobiohydrolases and endoglucanases during cellulose hydrolysis. The presence of β-glucosidases has a significant effect on reducing inhibition from hydrolytic products by hydrolysing the intermedia cellobiose. In this study, β-glucosidase TN0602 exhibited a high tolerance to glucose and high thermostability even after a long incubation (>72 h). Additionally, supplementing β-glucosidase TN0602 with microcrystalline cellulose, untreated corn straw and steam-exploded corn straw hydrolysis reactions containing a commercial cellulase led to an increased conversion rate in released glucose compared to hydrolysis without the addition of β-glucosidase (15.82, 30.62 and 35.21%, respectively); the increase of conversion rates were 61.86, 93.50 and 94.55%. It was thus shown that an obvious synergistic effect exists between TN0602 and cellulases for cellulose hydrolysis, suggesting its potential as a component of enzymatic cocktails for the conversion of lignocellulosic biomass to other chemicals.
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Influence of Randomly Inserted Feruloyl Esterase A on β-Glucosidase Activity in Trichoderma reesei. Appl Biochem Biotechnol 2017; 183:254-264. [DOI: 10.1007/s12010-017-2442-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 02/17/2017] [Indexed: 10/20/2022]
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Omics for understanding synergistic action of validamycin A and Trichoderma asperellum GDFS1009 against maize sheath blight pathogen. Sci Rep 2017; 7:40140. [PMID: 28057927 PMCID: PMC5216365 DOI: 10.1038/srep40140] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 11/30/2016] [Indexed: 12/19/2022] Open
Abstract
Sheath blight, causes by Rhizoctonia spp., threaten maize yield every year throughout the world. Trichoderma could degrade Rhizoctonia solani on maize mainly via competition and hyperparasitism, whereas validamycin A could efficiently inhibit the growth of R. solani via disturbing the energy system. By contrast, validamycin A is efficient but it takes effect in a short period, while Trichoderma takes effect in a long period though time-consuming. To overcome the disadvantages, Trichoderma asperellum GDFS1009 was used together with validamycin A. In vitro tests proved that the combined pathogen-inhibiting efficiency was significantly improved. Furthermore, results based on transcriptome and metabolome showed that validamycin A had no significant effects on growth, basic metabolism and main bio-control mechanisms of T. asperellum GDFS1009. Such few impacts may be attributed to detoxification and tolerance mechanism of T. asperellum GDFS1009. In addition, T. asperellum GDFS1009 has an ability to relieve the stress caused by validaymicn A. Meanwhile, liquid chromatography-mass spectrometry (LC-MS) results showed that only minor degradation (20%) of validamycin A was caused by T. asperellum GDFS1009 during cofermentation. All results together provide solid bases for validamycin A synergy with T. asperellum GDFS1009 in their combined biocontrol application.
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Li C, Lin F, Zhou L, Qin L, Li B, Zhou Z, Jin M, Chen Z. Cellulase hyper-production by Trichoderma reesei mutant SEU-7 on lactose. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:228. [PMID: 29034003 PMCID: PMC5628480 DOI: 10.1186/s13068-017-0915-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 09/23/2017] [Indexed: 05/13/2023]
Abstract
BACKGROUND The induction of cellulase production by insoluble carbon source cellulose was a common and efficient strategy, but has some drawbacks, such as difficult fermentation operation, substantial cellulase loss, long fermentation time, and high energy-consumption, resulting in high cost of cellulase production in industry. These drawbacks can be overcome if soluble carbon sources are utilized as the inducers for cellulase production. However, until now the induction efficiency of most soluble carbon sources, especially lactose and glucose, is still inferior to cellulose despite extensive efforts have been made by either optimizing the fermentation process or constructing the recombinant strains. Therefore, strain improvement by metabolic engineering for high induction efficiency of soluble carbon sources is of great interest. RESULTS Trichoderma reesei mutant SEU-7 was constructed from T. reesei RUT-C30 with the overexpression of endogenous gene β-glucosidase (BGL1) by insertional mutagenesis via Agrobacterium tumefaciens-mediated transformation (AMT). Compared to RUT-C30, SEU-7 displays substantially enhanced activities of both cellulase and hemicellulase when grown on either lactose or cellulose. The induction efficiency with lactose was found to be higher than cellulose in strain SEU-7. To the best of our knowledge, we achieved the highest FPase activity in SEU-7 in both batch culture (13.0 IU/mL) and fed-batch culture (47.0 IU/mL) on lactose. Moreover, SEU-7 displayed unrivaled pNPGase activity on lactose in both batch culture (81.0 IU/mL) and fed-batch culture (144.0 IU/mL) as compared to the other reported T. reesei strains in the literature grown in batch or fed-batch experiments on cellulose or lactose. This superiority of SEU-7 over RUT-C30 improves markedly the saccharification ability of SEU-7 on pretreated corn stover. The overexpression of gene BGL1 was found either at the mRNA or at the protein level in the mutant strains with increased cellulase production in comparison with RUT-C30, but only SEU-7 displayed much higher expression of gene BGL1 on lactose than on cellulose. Two copies of gene BGL1 were inserted into the chromosome of T. reesei SEU-7 between KI911141.1:347357 and KI911141.1:347979, replacing the original 623-bp fragment that is not within any genes' coding region. The qRT-PCR analysis revealed that the mRNA levels of both cellulase and hemicellulase were upregulated significantly in SEU-7, together with the MFS transporter CRT1 and the XYR1 nuclear importer KAP8. CONCLUSIONS Recombinant T. reesei SEU-7 displays hyper-production of both cellulase and hemicellulase on lactose with the highest FPase activity and pNPGase activity for T. reesei, enabling highly efficient saccharification of pretreated biomass. For the first time, the induction efficiency for cellulase production by lactose in T. reesei was reported to be higher than that by cellulose. This outperformance of T. reesei SEU-7, which is strain-specific, is attributed to both the overexpression of gene BGL and the collateral mutation. Moreover, the increased transcription levels of cellulase genes, the related transcription factors, and the MFS transporter CRT1 contribute to the outstanding cellulase production of SEU-7. Our research advances strain improvement to enhance the induction efficiency of soluble carbon sources to produce cost-effective cellulase and hemicellulase in industry.
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Affiliation(s)
- Chengcheng Li
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096 China
| | - Fengming Lin
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096 China
- 35 Jinxianghe Road, Xuanwu District, Nanjing, 210008 Jiangsu Province China
| | - Le Zhou
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096 China
| | - Lei Qin
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Nankai District, Tianjin, 300072 People’s Republic of China
| | - Bingzhi Li
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Nankai District, Tianjin, 300072 People’s Republic of China
| | - Zhihua Zhou
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032 China
| | - Mingjie Jin
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094 China
| | - Zhan Chen
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI 48109 USA
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Liu R, Chen L, Jiang Y, Zou G, Zhou Z. A novel transcription factor specifically regulates GH11 xylanase genes in Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:194. [PMID: 28785310 PMCID: PMC5541735 DOI: 10.1186/s13068-017-0878-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 07/19/2017] [Indexed: 05/12/2023]
Abstract
BACKGROUND The filamentous fungus Trichoderma reesei is widely utilized in industry for cellulase production, but its xylanase activity must be improved to enhance the accessibility of lignocellulose to cellulases. Several transcription factors play important roles in this progress; however, nearly all the reported transcription factors typically target both cellulase and hemi-cellulase genes. Specific xylanase transcription factor would be useful to regulate xylanase activity directly. RESULTS In this study, a novel zinc binuclear cluster transcription factor (jgi|Trire2|123881) was found to repress xylanase activity, but not cellulase activity, and was designated as SxlR (specialized xylanase regulator). Further investigations using real-time PCR and an electrophoretic mobility shift assay demonstrated that SxlR might bind the promoters of GH11 xylanase genes (xyn1, xyn2, and xyn5), but not those of GH10 (xyn3) and GH30 (xyn4) xylanase genes, and thus regulate their transcription and expression directly. We also identified the binding consensus sequence of SxlR as 5'- CATCSGSWCWMSA-3'. The deletion of SxlR in T. reesei RUT-C30 to generate the mutant ∆sxlr strain resulted in higher xylanase activity as well as higher hydrolytic efficiency on pretreated rice straw. CONCLUSIONS Our study characterizes a novel specific transcriptional repressor of GH11 xylanase genes, which adds to our understanding of the regulatory system for the synthesis and secretion of cellulase and hemi-cellulase in T. reesei. The deletion of SxlR may also help to improve the hydrolytic efficiency of T. reesei for lignocellulose degradation by increasing the xylanase-to-cellulase ratio.
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Affiliation(s)
- Rui Liu
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Science, Fenglin Rd 300, Shanghai, 200032 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Ling Chen
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Science, Fenglin Rd 300, Shanghai, 200032 China
| | - Yanping Jiang
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Science, Fenglin Rd 300, Shanghai, 200032 China
| | - Gen Zou
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Science, Fenglin Rd 300, Shanghai, 200032 China
| | - Zhihua Zhou
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Science, Fenglin Rd 300, Shanghai, 200032 China
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Ellilä S, Fonseca L, Uchima C, Cota J, Goldman GH, Saloheimo M, Sacon V, Siika-aho M. Development of a low-cost cellulase production process using Trichoderma reesei for Brazilian biorefineries. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:30. [PMID: 28184245 PMCID: PMC5289010 DOI: 10.1186/s13068-017-0717-0] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 01/25/2017] [Indexed: 05/21/2023]
Abstract
BACKGROUND During the past few years, the first industrial-scale cellulosic ethanol plants have been inaugurated. Although the performance of the commercial cellulase enzymes used in this process has greatly improved over the past decade, cellulases still represent a very significant operational cost. Depending on the region, transport of cellulases from a central production facility to a biorefinery may significantly add to enzyme cost. The aim of the present study was to develop a simple, cost-efficient cellulase production process that could be employed locally at a Brazilian sugarcane biorefinery. RESULTS Our work focused on two main topics: growth medium formulation and strain improvement. We evaluated several Brazilian low-cost industrial residues for their potential in cellulase production. Among the solid residues evaluated, soybean hulls were found to display clearly the most desirable characteristics. We engineered a Trichoderma reesei strain to secrete cellulase in the presence of repressing sugars, enabling the use of sugarcane molasses as an additional carbon source. In addition, we added a heterologous β-glucosidase to improve the performance of the produced enzymes in hydrolysis. Finally, the addition of an invertase gene from Aspegillus niger into our strain allowed it to consume sucrose from sugarcane molasses directly. Preliminary cost analysis showed that the overall process can provide for very low-cost enzyme with good hydrolysis performance on industrially pre-treated sugarcane straw. CONCLUSIONS In this study, we showed that with relatively few genetic modifications and the right growth medium it is possible to produce considerable amounts of well-performing cellulase at very low cost in Brazil using T. reesei. With further enhancements and optimization, such a system could provide a viable alternative to delivered commercial cellulases.
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Affiliation(s)
- Simo Ellilä
- VTT Brasil Ltda., Barueri, Sao Paulo Brazil
- VTT Technical Research Centre of Finland, Tietotie 2, 02044 Espoo, Finland
| | | | | | - Junio Cota
- VTT Brasil Ltda., Barueri, Sao Paulo Brazil
- Instituto de Ciências Agrárias, Universidade Federal de Minas Gerais (UFMG), Montes Claros, MG Brazil
| | - Gustavo Henrique Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de Sao Paulo, Ribeirão Preto, SP Brazil
| | - Markku Saloheimo
- VTT Technical Research Centre of Finland, Tietotie 2, 02044 Espoo, Finland
| | - Vera Sacon
- VTT Brasil Ltda., Barueri, Sao Paulo Brazil
| | - Matti Siika-aho
- VTT Technical Research Centre of Finland, Tietotie 2, 02044 Espoo, Finland
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RNA Sequencing Reveals Xyr1 as a Transcription Factor Regulating Gene Expression beyond Carbohydrate Metabolism. BIOMED RESEARCH INTERNATIONAL 2016; 2016:4841756. [PMID: 28116297 PMCID: PMC5223008 DOI: 10.1155/2016/4841756] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/06/2016] [Indexed: 12/04/2022]
Abstract
Xyr1 has been demonstrated to be the main transcription activator of (hemi)cellulases in the well-known cellulase producer Trichoderma reesei. This study comprehensively investigates the genes regulated by Xyr1 through RNA sequencing to produce the transcription profiles of T. reesei Rut-C30 and its xyr1 deletion mutant (Δxyr1), cultured on lignocellulose or glucose. xyr1 deletion resulted in 467 differentially expressed genes on inducing medium. Almost all functional genes involved in (hemi)cellulose degradation and many transporters belonging to the sugar porter family in the major facilitator superfamily (MFS) were downregulated in Δxyr1. By contrast, all differentially expressed protease, lipase, chitinase, some ATP-binding cassette transporters, and heat shock protein-encoding genes were upregulated in Δxyr1. When cultured on glucose, a total of 281 genes were expressed differentially in Δxyr1, most of which were involved in energy, solute transport, lipid, amino acid, and monosaccharide as well as secondary metabolism. Electrophoretic mobility shift assays confirmed that the intracellular β-glucosidase bgl2, the putative nonenzymatic cellulose-attacking gene cip1, the MFS lactose transporter lp, the nmrA-like gene, endo T, the acid protease pepA, and the small heat shock protein hsp23 were probable Xyr1-targets. These results might help elucidate the regulation system for synthesis and secretion of (hemi)cellulases in T. reesei Rut-C30.
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Increased yield of β-glucosidase-catalyzed hydrolysis reactions in the presence of betaine-type metabolite analog. Bioprocess Biosyst Eng 2016; 40:153-159. [PMID: 27655352 DOI: 10.1007/s00449-016-1684-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Accepted: 09/14/2016] [Indexed: 10/21/2022]
Abstract
β-Glucosidases (EC 3.2.1.21), abundant enzymes distributed in animals, plants and microorganism, has been generating lots of attentions for bioethanol production from cellulosic biomass. In this study, using three different origins of β-glucosidases, glucose productivity of β-glucosidase-catalyzed hydrolysis reactions in the presence of synthetic betaine-type metabolite analog (2-N,N,N-tri-n-butylammonium) acetate, was investigated. By the addition of the analog, the hydrolysis yields for all β-glucosidases was highly improved from 4-13 to 64-100 %. To understand the factors affecting on the yield enhancements, the kinetic parameters, inhibition constants of end-product and temporal stability of β-glucosidases were compared. As a result, enhancement of the yields is mainly related to the increase in the temporal stability of β-glucosidases in the presence of the analog. The present findings lead to not only improve the glucose productivity of β-glucosidase-catalyzed hydrolysis reaction toward bioethanol production but also apply to a new stabilization method for various unstable enzymes.
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Zhang F, Bai F, Zhao X. Enhanced cellulase production from Trichoderma reesei Rut-C30 by engineering with an artificial zinc finger protein library. Biotechnol J 2016; 11:1282-1290. [PMID: 27578229 DOI: 10.1002/biot.201600227] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Revised: 08/25/2016] [Accepted: 08/29/2016] [Indexed: 01/03/2023]
Abstract
Trichoderma reesei Rut-C30 is a well-known cellulase producer, and improvement of its cellulase production is of great interest. An artificial zinc finger protein (AZFP) library is constructed for expression in T. reesei Rut-C30, and a mutant strain T. reesei U3 is selected based on its enhanced cellulase production. The U3 mutant shows a 55% rise in filter paper activity and 8.1-fold increased β-glucosidase activity, when compared to the native strain T. reesei Rut-C30. It is demonstrated that enhanced β-glucosidase activity was due to elevated transcription level of β-glucosidase gene in the U3 mutant. Moreover, significant elevation in transcription levels of several putative Azfp-U3 target genes is detected in the U3 mutant, including genes encoding hypothetical transcription factors and a putative glycoside hydrolase. Furthermore, U3 cellulase shows 115% higher glucose yield from pretreated corn stover, when compared to the cellulase of T. reesei Rut-C30. These results demonstrate that AZFP can be used to improve cellulase production in T. reesei Rut-C30. Our current work offers the establishment of an alternative strategy to develop fungal cell factories for improved production of high value industrial products.
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Affiliation(s)
- Fei Zhang
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, China
| | - Fengwu Bai
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, China.,State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xinqing Zhao
- State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
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