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Castañeda-Casasola CC, Nieto-Jacobo MF, Soares A, Padilla-Padilla EA, Anducho-Reyes MA, Brown C, Soth S, Esquivel-Naranjo EU, Hampton J, Mendoza-Mendoza A. Unveiling a Microexon Switch: Novel Regulation of the Activities of Sugar Assimilation and Plant-Cell-Wall-Degrading Xylanases and Cellulases by Xlr2 in Trichoderma virens. Int J Mol Sci 2024; 25:5172. [PMID: 38791210 PMCID: PMC11121469 DOI: 10.3390/ijms25105172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 05/02/2024] [Accepted: 05/06/2024] [Indexed: 05/26/2024] Open
Abstract
Functional microexons have not previously been described in filamentous fungi. Here, we describe a novel mechanism of transcriptional regulation in Trichoderma requiring the inclusion of a microexon from the Xlr2 gene. In low-glucose environments, a long mRNA including the microexon encodes a protein with a GAL4-like DNA-binding domain (Xlr2-α), whereas in high-glucose environments, a short mRNA that is produced encodes a protein lacking this DNA-binding domain (Xlr2-β). Interestingly, the protein isoforms differ in their impact on cellulase and xylanase activity. Deleting the Xlr2 gene reduced both xylanase and cellulase activity and growth on different carbon sources, such as carboxymethylcellulose, xylan, glucose, and arabinose. The overexpression of either Xlr2-α or Xlr2-β in T. virens showed that the short isoform (Xlr2-β) caused higher xylanase activity than the wild types or the long isoform (Xlr2-α). Conversely, cellulase activity did not increase when overexpressing Xlr2-β but was increased with the overexpression of Xlr2-α. This is the first report of a novel transcriptional regulation mechanism of plant-cell-wall-degrading enzyme activity in T. virens. This involves the differential expression of a microexon from a gene encoding a transcriptional regulator.
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Affiliation(s)
- Cynthia Coccet Castañeda-Casasola
- Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln 7647, New Zealand; (C.C.C.-C.); (A.S.); (E.A.P.-P.); (S.S.); (E.U.E.-N.); (J.H.)
- Laboratorio de AgroBiotecnología, Universidad Politécnica de Pachuca, Carretera Pachuca-Cd. Sahagún, km 20, ExHacienda de Santa Bárbara, Zempoala 43830, Mexico;
- Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria, Centro Nacional de Referencia Fitosanitaria, Tecamac 55740, Mexico
| | | | - Amanda Soares
- Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln 7647, New Zealand; (C.C.C.-C.); (A.S.); (E.A.P.-P.); (S.S.); (E.U.E.-N.); (J.H.)
| | - Emir Alejandro Padilla-Padilla
- Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln 7647, New Zealand; (C.C.C.-C.); (A.S.); (E.A.P.-P.); (S.S.); (E.U.E.-N.); (J.H.)
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand;
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca 04510, Mexico
| | - Miguel Angel Anducho-Reyes
- Laboratorio de AgroBiotecnología, Universidad Politécnica de Pachuca, Carretera Pachuca-Cd. Sahagún, km 20, ExHacienda de Santa Bárbara, Zempoala 43830, Mexico;
| | - Chris Brown
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand;
| | - Sereyboth Soth
- Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln 7647, New Zealand; (C.C.C.-C.); (A.S.); (E.A.P.-P.); (S.S.); (E.U.E.-N.); (J.H.)
| | - Edgardo Ulises Esquivel-Naranjo
- Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln 7647, New Zealand; (C.C.C.-C.); (A.S.); (E.A.P.-P.); (S.S.); (E.U.E.-N.); (J.H.)
- Unit for Basic and Applied Microbiology, Faculty of Natural Sciences, Autonomous University of Queretaro, Queretaro 76230, Mexico
| | - John Hampton
- Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln 7647, New Zealand; (C.C.C.-C.); (A.S.); (E.A.P.-P.); (S.S.); (E.U.E.-N.); (J.H.)
| | - Artemio Mendoza-Mendoza
- Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln 7647, New Zealand; (C.C.C.-C.); (A.S.); (E.A.P.-P.); (S.S.); (E.U.E.-N.); (J.H.)
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Wang L, Zhao Y, Chen S, Wen X, Anjago WM, Tian T, Chen Y, Zhang J, Deng S, Jiu M, Fu P, Zhou D, Druzhinina IS, Wei L, Daly P. Growth, Enzymatic, and Transcriptomic Analysis of xyr1 Deletion Reveals a Major Regulator of Plant Biomass-Degrading Enzymes in Trichoderma harzianum. Biomolecules 2024; 14:148. [PMID: 38397385 PMCID: PMC10887015 DOI: 10.3390/biom14020148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 12/24/2023] [Accepted: 01/09/2024] [Indexed: 02/25/2024] Open
Abstract
The regulation of plant biomass degradation by fungi is critical to the carbon cycle, and applications in bioproducts and biocontrol. Trichoderma harzianum is an important plant biomass degrader, enzyme producer, and biocontrol agent, but few putative major transcriptional regulators have been deleted in this species. The T. harzianum ortholog of the transcriptional activator XYR1/XlnR/XLR-1 was deleted, and the mutant strains were analyzed through growth profiling, enzymatic activities, and transcriptomics on cellulose. From plate cultures, the Δxyr1 mutant had reduced growth on D-xylose, xylan, and cellulose, and from shake-flask cultures with cellulose, the Δxyr1 mutant had ~90% lower β-glucosidase activity, and no detectable β-xylosidase or cellulase activity. The comparison of the transcriptomes from 18 h shake-flask cultures on D-fructose, without a carbon source, and cellulose, showed major effects of XYR1 deletion whereby the Δxyr1 mutant on cellulose was transcriptionally most similar to the cultures without a carbon source. The cellulose induced 43 plant biomass-degrading CAZymes including xylanases as well as cellulases, and most of these had massively lower expression in the Δxyr1 mutant. The expression of a subset of carbon catabolic enzymes, other transcription factors, and sugar transporters was also lower in the Δxyr1 mutant on cellulose. In summary, T. harzianum XYR1 is the master regulator of cellulases and xylanases, as well as regulating carbon catabolic enzymes.
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Affiliation(s)
- Lunji Wang
- College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471023, China; (L.W.); (Y.Z.); (X.W.); (M.J.)
| | - Yishen Zhao
- College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471023, China; (L.W.); (Y.Z.); (X.W.); (M.J.)
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (S.C.); (W.M.A.); (T.T.); (Y.C.); (J.Z.); (S.D.); (D.Z.)
| | - Siqiao Chen
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (S.C.); (W.M.A.); (T.T.); (Y.C.); (J.Z.); (S.D.); (D.Z.)
- Fungal Genomics Laboratory (FungiG), Nanjing Agricultural University, Nanjing 210095, China
| | - Xian Wen
- College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471023, China; (L.W.); (Y.Z.); (X.W.); (M.J.)
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (S.C.); (W.M.A.); (T.T.); (Y.C.); (J.Z.); (S.D.); (D.Z.)
| | - Wilfred Mabeche Anjago
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (S.C.); (W.M.A.); (T.T.); (Y.C.); (J.Z.); (S.D.); (D.Z.)
| | - Tianchi Tian
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (S.C.); (W.M.A.); (T.T.); (Y.C.); (J.Z.); (S.D.); (D.Z.)
| | - Yajuan Chen
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (S.C.); (W.M.A.); (T.T.); (Y.C.); (J.Z.); (S.D.); (D.Z.)
- Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining and Technology, Xuzhou 221116, China
| | - Jinfeng Zhang
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (S.C.); (W.M.A.); (T.T.); (Y.C.); (J.Z.); (S.D.); (D.Z.)
| | - Sheng Deng
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (S.C.); (W.M.A.); (T.T.); (Y.C.); (J.Z.); (S.D.); (D.Z.)
| | - Min Jiu
- College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471023, China; (L.W.); (Y.Z.); (X.W.); (M.J.)
| | - Pengxiao Fu
- Jiangsu Coastal Ecological Science and Technology Development Co., Ltd., Nanjing 210036, China;
| | - Dongmei Zhou
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (S.C.); (W.M.A.); (T.T.); (Y.C.); (J.Z.); (S.D.); (D.Z.)
| | - Irina S. Druzhinina
- Department of Accelerated Taxonomy, The Royal Botanic Gardens Kew, London TW9 3AE, UK;
| | - Lihui Wei
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (S.C.); (W.M.A.); (T.T.); (Y.C.); (J.Z.); (S.D.); (D.Z.)
| | - Paul Daly
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (S.C.); (W.M.A.); (T.T.); (Y.C.); (J.Z.); (S.D.); (D.Z.)
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Xu W, Ren Y, Xia Y, Liu L, Meng X, Chen G, Zhang W, Liu W. A novel transcriptional repressor specifically regulates xylanase gene 1 in Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:161. [PMID: 37891680 PMCID: PMC10612264 DOI: 10.1186/s13068-023-02417-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Accepted: 10/20/2023] [Indexed: 10/29/2023]
Abstract
BACKGROUND The well-known industrial fungus Trichoderma reesei has an excellent capability of secreting a large amount of cellulases and xylanases. The induced expression of cellulase and xylanase genes is tightly controlled at the transcriptional level. However, compared to the intensive studies on the intricate regulatory mechanism of cellulase genes, efforts to understand how xylanase genes are regulated are relatively limited, which impedes the further improvement of xylanase production by T. reesei via rational strain engineering. RESULTS To identify transcription factors involved in regulating xylanase gene expression in T. reesei, yeast one-hybrid screen was performed based on the promoters of two major extracellular xylanase genes xyn1 and xyn2. A putative transcription factor named XTR1 showing significant binding capability to the xyn1 promoter but not that of xyn2, was successfully isolated. Deletion of xtr1 significantly increased the transcriptional level of xyn1, but only exerted a minor promoting effect on that of xyn2. The xylanase activity was increased by ~ 50% with XTR1 elimination but the cellulase activity was hardly affected. Subcellular localization analysis of XTR1 fused to a green fluorescence protein demonstrated that XTR1 is a nuclear protein. Further analyses revealed the precise binding site of XTR1 and nucleotides critical for the binding within the xyn1 promoter. Moreover, competitive EMSAs indicated that XTR1 competes with the essential transactivator XYR1 for binding to the xyn1 promoter. CONCLUSIONS XTR1 represents a new transcriptional repressor specific for controlling xylanase gene expression. Isolation and functional characterization of this new factor not only contribute to further understanding the stringent regulatory network of xylanase genes, but also provide important clues for boosting xylanase biosynthesis in T. reesei.
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Affiliation(s)
- Wenqiang Xu
- State Key Laboratory of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, 266237, People's Republic of China
- Shandong Lishan Biotechnology Co., LTD, Jinan, China
| | - Yajing Ren
- State Key Laboratory of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, 266237, People's Republic of China
| | - Yuxiao Xia
- State Key Laboratory of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, 266237, People's Republic of China
| | - Lin Liu
- State Key Laboratory of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, 266237, People's Republic of China
| | - Xiangfeng Meng
- State Key Laboratory of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, 266237, People's Republic of China
| | - Guanjun Chen
- State Key Laboratory of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, 266237, People's Republic of China
| | - Weixin Zhang
- State Key Laboratory of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, 266237, People's Republic of China.
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, 266237, People's Republic of China
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Exploring the multi-level regulation of lignocellulases in the filamentous fungus Trichoderma guizhouense NJAU4742 from an omics perspective. Microb Cell Fact 2022; 21:144. [PMID: 35842666 PMCID: PMC9288086 DOI: 10.1186/s12934-022-01869-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 07/07/2022] [Indexed: 11/18/2022] Open
Abstract
Background Filamentous fungi are highly efficient at deconstructing plant biomass by secreting a variety of enzymes, but the complex enzymatic regulation underlying this process is not conserved and remains unclear. Results In this study, cellulases and xylanases could specifically respond to Avicel- and xylan-induction, respectively, in lignocellulose-degrading strain Trichoderma guizhouense NJAU4742, however, the differentially regulated cellulases and xylanases were both under the absolute control of the same TgXyr1-mediated pathway. Further analysis showed that Avicel could specifically induce cellulase expression, which supported the existence of an unknown specific regulator of cellulases in strain NJAU4742. The xylanase secretion is very complex, GH10 endoxylanases could only be induced by Avicel, while, other major xylanases were significantly induced by both Avicel and xylan. For GH10 xylanases, an unknown specific regulator was also deduced to exist. Meanwhile, the post-transcriptional inhibition was subsequently suggested to stop the Avicel-induced xylanases secretion, which explained the specifically high xylanase activities when induced by xylan in strain NJAU4742. Additionally, an economical strategy used by strain NJAU4742 was proposed to sense the environmental lignocellulose under the carbon starvation condition, that only slightly activating 4 lignocellulose-degrading genes before largely secreting all 33 TgXyr1-controlled lignocellulases if confirming the existence of lignocellulose components. Conclusions This study, aiming to explore the unknown mechanisms of plant biomass-degrading enzymes regulation through the combined omics analysis, will open directions for in-depth understanding the complex carbon utilization in filamentous fungi. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-022-01869-3.
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Mattam AJ, Chaudhari YB, Velankar HR. Factors regulating cellulolytic gene expression in filamentous fungi: an overview. Microb Cell Fact 2022; 21:44. [PMID: 35317826 PMCID: PMC8939176 DOI: 10.1186/s12934-022-01764-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 02/27/2022] [Indexed: 12/19/2022] Open
Abstract
The growing demand for biofuels such as bioethanol has led to the need for identifying alternative feedstock instead of conventional substrates like molasses, etc. Lignocellulosic biomass is a relatively inexpensive feedstock that is available in abundance, however, its conversion to bioethanol involves a multistep process with different unit operations such as size reduction, pretreatment, saccharification, fermentation, distillation, etc. The saccharification or enzymatic hydrolysis of cellulose to glucose involves a complex family of enzymes called cellulases that are usually fungal in origin. Cellulose hydrolysis requires the synergistic action of several classes of enzymes, and achieving the optimum secretion of these simultaneously remains a challenge. The expression of fungal cellulases is controlled by an intricate network of transcription factors and sugar transporters. Several genetic engineering efforts have been undertaken to modulate the expression of cellulolytic genes, as well as their regulators. This review, therefore, focuses on the molecular mechanism of action of these transcription factors and their effect on the expression of cellulases and hemicellulases.
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Affiliation(s)
- Anu Jose Mattam
- Hindustan Petroleum Green R and D Centre (HPGRDC), KIADB Industrial Area, Tarabanahalli, Devanagundi, Hoskote, Bangalore, 560067, India
| | - Yogesh Babasaheb Chaudhari
- Hindustan Petroleum Green R and D Centre (HPGRDC), KIADB Industrial Area, Tarabanahalli, Devanagundi, Hoskote, Bangalore, 560067, India
| | - Harshad Ravindra Velankar
- Hindustan Petroleum Green R and D Centre (HPGRDC), KIADB Industrial Area, Tarabanahalli, Devanagundi, Hoskote, Bangalore, 560067, India.
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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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Xu W, Fang Y, Ding M, Ren Y, Meng X, Chen G, Zhang W, Liu W. Elimination of the Sugar Transporter GAT1 Increased Xylanase I Production in Trichoderma reesei. Front Microbiol 2022; 13:810066. [PMID: 35154055 PMCID: PMC8825865 DOI: 10.3389/fmicb.2022.810066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 01/04/2022] [Indexed: 11/17/2022] Open
Abstract
The filamentous fungus Trichoderma reesei secretes large quantities of cellulases and hemicellulases that have found wide applications in industry. Compared with extensive studies on the mechanism controlling cellulase gene expression, less is known about the regulatory mechanism behind xylanase gene expression. Herein, several putative sugar transporter encoding genes that showed significant upregulation on xylan were identified in T. reesei. Deletion of one such gene, gat1, resulted in increased xylanase production but hardly affected cellulase induction. Further analyses demonstrated that deletion of gat1 markedly increased XYNI production at the transcriptional level and only exerted a minor effect on XYNII synthesis. In contrast, overexpressing gat1 caused a continuous decrease in xyn1 expression. Deletion of gat1 also affected the expression of xyn1 and pectinase genes when T. reesei was cultivated with galacturonic acid as the sole carbon source. Transcriptome analyses of Δgat1 and its parental strain identified 255 differentially expressed genes that are enriched in categories of glycoside hydrolases, lipid metabolism, transporters, and transcriptional factors. The results thus implicate a repressive role of the sugar transporter GAT1 in xyn1 expression and reveal that distinct regulatory mechanisms may exist in controlling the expression of different xylanase genes in T. reesei.
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Affiliation(s)
- Wenqiang Xu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yu Fang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Mingyang Ding
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yajing Ren
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Xiangfeng Meng
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Guanjun Chen
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Weixin Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
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Zhang W, Guo J, Wu X, Ren Y, Li C, Meng X, Liu W. Reformulating the Hydrolytic Enzyme Cocktail of Trichoderma reesei by Combining XYR1 Overexpression and Elimination of Four Major Cellulases to Improve Saccharification of Corn Fiber. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:211-222. [PMID: 34935374 DOI: 10.1021/acs.jafc.1c05946] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The industrial fungus Trichoderma reesei has an outstanding capability of secreting an enzyme cocktail comprising multiple plant biomass-degrading enzymes. Herein, the overexpression of XYR1, the master transactivator controlling (hemi)cellulase gene expression, was performed in T. reesei lacking four main cellulase-encoding genes. The resultant strain Δ4celOExyr1 was able to produce a dramatically different profile of secretory proteins on soluble glucose or lactose compared with that of the wild-type T. reesei. The Δ4celOExyr1 secretome included cellulases EGIII and BGLI as well as several hemicellulases and nonhydrolytic cellulose degradation-associated proteins that are not preferentially induced in the wild-type T. reesei strain. Δ4celOExyr1 produced a significant amount of α-arabinofuranosidase I on lactose, and the crude enzyme cocktail of Δ4celOExyr1 not only released a considerable quantity of glucose but also exhibited remarkable performance in the hydrolytic release of xylose, arabinose, and mannose from un-pretreated corn fiber. These results showed that the engineered T. reesei strain holds great potential for improving the saccharification efficiency of the hemicellulosic constituents within corn fiber.
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Affiliation(s)
- Weixin Zhang
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
| | - Junqi Guo
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
| | - Xiaoxiao Wu
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
| | - Yajing Ren
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
| | - Chunyan Li
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
| | - Xiangfeng Meng
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
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9
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Madhavan A, Arun KB, Sindhu R, Alphonsa Jose A, Pugazhendhi A, Binod P, Sirohi R, Reshmy R, Kumar Awasthi M. Engineering interventions in industrial filamentous fungal cell factories for biomass valorization. BIORESOURCE TECHNOLOGY 2022; 344:126209. [PMID: 34715339 DOI: 10.1016/j.biortech.2021.126209] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/18/2021] [Accepted: 10/20/2021] [Indexed: 05/15/2023]
Abstract
Filamentous fungi possess versatile capabilities for synthesizing a variety of valuable bio compounds, including enzymes, organic acids and small molecule secondary metabolites. The advancements of genetic and metabolic engineering techniques and the availability of sequenced genomes discovered their potential as expression hosts for recombinant protein production. Remarkably, plant-biomass degrading filamentous fungi show the unique capability to decompose lignocellulose, an extremely recalcitrant biopolymer. The basic biochemical approaches have motivated several industrial processes for lignocellulose biomass valorisation into fermentable sugars and other biochemical for biofuels, biomolecules, and biomaterials. The review gives insight into current trends in engineering filamentous fungi for enzymes, fuels, and chemicals from lignocellulose biomass. This review describes the variety of enzymes and compounds that filamentous fungi produce, engineering of filamentous fungi for biomass valorisation with a special focus on lignocellulolytic enzymes and other bulk chemicals.
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Affiliation(s)
- Aravind Madhavan
- Rajiv Gandhi Centre for Biotechnology, Jagathy, Trivandrum 695 014, India.
| | - K B Arun
- Rajiv Gandhi Centre for Biotechnology, Jagathy, Trivandrum 695 014, India
| | - Raveendran Sindhu
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum 695 019, India
| | - Anju Alphonsa Jose
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum 695 019, India
| | | | - Parameswaran Binod
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum 695 019, India
| | - Ranjna Sirohi
- Department of Chemical & Biological Engineering, Korea University, Seoul 136713, Republic of Korea; Centre for Energy & Environmental Sustainability, Lucknow 226001. Uttar Pradesh, India
| | - R Reshmy
- Post Graduate and Research Department of Chemistry, Bishop Moore College, Mavelikara 690 110, Kerala, India
| | - Mukesh Kumar Awasthi
- College of Natural Resources and Environment, Northwest A & F University, Yangling, Shaanxi 712 100, PR China
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10
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Filho JAF, Rosolen RR, Almeida DA, de Azevedo PHC, Motta MLL, Aono AH, dos Santos CA, Horta MAC, de Souza AP. Trends in biological data integration for the selection of enzymes and transcription factors related to cellulose and hemicellulose degradation in fungi. 3 Biotech 2021; 11:475. [PMID: 34777932 PMCID: PMC8548487 DOI: 10.1007/s13205-021-03032-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 10/15/2021] [Indexed: 12/13/2022] Open
Abstract
Fungi are key players in biotechnological applications. Although several studies focusing on fungal diversity and genetics have been performed, many details of fungal biology remain unknown, including how cellulolytic enzymes are modulated within these organisms to allow changes in main plant cell wall compounds, cellulose and hemicellulose, and subsequent biomass conversion. With the advent and consolidation of DNA/RNA sequencing technology, different types of information can be generated at the genomic, structural and functional levels, including the gene expression profiles and regulatory mechanisms of these organisms, during degradation-induced conditions. This increase in data generation made rapid computational development necessary to deal with the large amounts of data generated. In this context, the origination of bioinformatics, a hybrid science integrating biological data with various techniques for information storage, distribution and analysis, was a fundamental step toward the current state-of-the-art in the postgenomic era. The possibility of integrating biological big data has facilitated exciting discoveries, including identifying novel mechanisms and more efficient enzymes, increasing yields, reducing costs and expanding opportunities in the bioprocess field. In this review, we summarize the current status and trends of the integration of different types of biological data through bioinformatics approaches for biological data analysis and enzyme selection.
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Affiliation(s)
- Jaire A. Ferreira Filho
- Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, SP Brazil
| | - Rafaela R. Rosolen
- Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, SP Brazil
| | - Deborah A. Almeida
- Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, SP Brazil
| | - Paulo Henrique C. de Azevedo
- Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, SP Brazil
| | - Maria Lorenza L. Motta
- Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, SP Brazil
| | - Alexandre H. Aono
- Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, SP Brazil
| | - Clelton A. dos Santos
- Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, SP Brazil
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP Brazil
| | - Maria Augusta C. Horta
- Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, SP Brazil
- Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP Brazil
| | - Anete P. de Souza
- Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, SP Brazil
- Department of Plant Biology, Institute of Biology, UNICAMP, Universidade Estadual de Campinas, Campinas, SP 13083-875 Brazil
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Yan S, Xu Y, Yu XW. Rational engineering of xylanase hyper-producing system in Trichoderma reesei for efficient biomass degradation. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:90. [PMID: 33832521 PMCID: PMC8033665 DOI: 10.1186/s13068-021-01943-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/27/2021] [Indexed: 05/27/2023]
Abstract
BACKGROUND Filamentous fungus Trichoderma reesei has been widely used as a workhorse for cellulase and xylanase productions. Xylanase has been reported as the crucial accessory enzyme in the degradation of lignocellulose for higher accessibility of cellulase. In addition, the efficient hydrolysis of xylan needs the co-work of multiple xylanolytic enzymes, which rise an increasing demand for the high yield of xylanase for efficient biomass degradation. RESULTS In this study, a xylanase hyper-producing system in T. reesei was established by tailoring two transcription factors, XYR1 and ACE1, and homologous overexpression of the major endo-xylanase XYNII. The expressed xylanase cocktail contained 5256 U/mL xylanase activity and 9.25 U/mL β-xylosidase (pNPXase) activity. Meanwhile, the transcription level of the xylanolytic genes in the strain with XYR1 overexpressed was upregulated, which was well correlated with the amount of XYR1-binding sites. In addition, the higher expression of associated xylanolytic enzymes would result in more efficient xylan hydrolysis. Besides, 2310-3085 U/mL of xylanase activities were achieved using soluble carbon source, which was more efficient and economical than the traditional strategy of xylan induction. Unexpectedly, deletion of ace1 in C30OExyr1 did not give any improvement, which might be the result of the disturbed function of the complex formed between ACE1 and XYR1. The enzymatic hydrolysis of alkali pretreated corn stover using the crude xylanase cocktails as accessory enzymes resulted in a 36.64% increase in saccharification efficiency with the ratio of xylanase activity vs FPase activity at 500, compared to that using cellulase alone. CONCLUSIONS An efficient and economical xylanase hyper-producing platform was developed in T. reesei RUT-C30. The novel platform with outstanding ability for crude xylanase cocktail production would greatly fit in biomass degradation and give a new perspective of further engineering in T. reesei for industrial purposes.
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Affiliation(s)
- Su Yan
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China
| | - Yan Xu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China
| | - Xiao-Wei Yu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China.
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12
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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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Pirayre A, Duval L, Blugeon C, Firmo C, Perrin S, Jourdier E, Margeot A, Bidard F. Glucose-lactose mixture feeds in industry-like conditions: a gene regulatory network analysis on the hyperproducing Trichoderma reesei strain Rut-C30. BMC Genomics 2020; 21:885. [PMID: 33302864 PMCID: PMC7731781 DOI: 10.1186/s12864-020-07281-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 11/25/2020] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The degradation of cellulose and hemicellulose molecules into simpler sugars such as glucose is part of the second generation biofuel production process. Hydrolysis of lignocellulosic substrates is usually performed by enzymes produced and secreted by the fungus Trichoderma reesei. Studies identifying transcription factors involved in the regulation of cellulase production have been conducted but no overview of the whole regulation network is available. A transcriptomic approach with mixtures of glucose and lactose, used as a substrate for cellulase induction, was used to help us decipher missing parts in the network of T. reesei Rut-C30. RESULTS Experimental results on the Rut-C30 hyperproducing strain confirmed the impact of sugar mixtures on the enzymatic cocktail composition. The transcriptomic study shows a temporal regulation of the main transcription factors and a lactose concentration impact on the transcriptional profile. A gene regulatory network built using BRANE Cut software reveals three sub-networks related to i) a positive correlation between lactose concentration and cellulase production, ii) a particular dependence of the lactose onto the β-glucosidase regulation and iii) a negative regulation of the development process and growth. CONCLUSIONS This work is the first investigating a transcriptomic study regarding the effects of pure and mixed carbon sources in a fed-batch mode. Our study expose a co-orchestration of xyr1, clr2 and ace3 for cellulase and hemicellulase induction and production, a fine regulation of the β-glucosidase and a decrease of growth in favor of cellulase production. These conclusions provide us with potential targets for further genetic engineering leading to better cellulase-producing strains in industry-like conditions.
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Affiliation(s)
- Aurélie Pirayre
- IFP Energies nouvelles, 1 et 4 avenue de Bois-Préau, Rueil-Malmaison, 92852, France.
| | - Laurent Duval
- IFP Energies nouvelles, 1 et 4 avenue de Bois-Préau, Rueil-Malmaison, 92852, France
- Laboratoire d'Informatique Gaspard-Monge (LIGM), ESIEE Paris, Université-Gustave Eiffel, Marne-la-Vallée, F-77454, France
| | - Corinne Blugeon
- Genomic facility, Institut de Biologie de l'ENS (IBENS), Département de biologie, École normale supérieure, CNRS, INSERM, Université PSL, Paris, 75005, France
| | - Cyril Firmo
- Genomic facility, Institut de Biologie de l'ENS (IBENS), Département de biologie, École normale supérieure, CNRS, INSERM, Université PSL, Paris, 75005, France
| | - Sandrine Perrin
- Genomic facility, Institut de Biologie de l'ENS (IBENS), Département de biologie, École normale supérieure, CNRS, INSERM, Université PSL, Paris, 75005, France
| | - Etienne Jourdier
- IFP Energies nouvelles, 1 et 4 avenue de Bois-Préau, Rueil-Malmaison, 92852, France
| | - Antoine Margeot
- IFP Energies nouvelles, 1 et 4 avenue de Bois-Préau, Rueil-Malmaison, 92852, France
| | - Frédérique Bidard
- IFP Energies nouvelles, 1 et 4 avenue de Bois-Préau, Rueil-Malmaison, 92852, France
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Molecular engineering to improve lignocellulosic biomass based applications using filamentous fungi. ADVANCES IN APPLIED MICROBIOLOGY 2020; 114:73-109. [PMID: 33934853 DOI: 10.1016/bs.aambs.2020.09.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Lignocellulosic biomass is an abundant and renewable resource, and its utilization has become the focus of research and biotechnology applications as a very promising raw material for the production of value-added compounds. Filamentous fungi play an important role in the production of various lignocellulolytic enzymes, while some of them have also been used for the production of important metabolites. However, wild type strains have limited efficiency in enzyme production or metabolic conversion, and therefore many efforts have been made to engineer improved strains. Examples of this are the manipulation of transcriptional regulators and/or promoters of enzyme-encoding genes to increase gene expression, and protein engineering to improve the biochemical characteristics of specific enzymes. This review provides and overview of the applications of filamentous fungi in lignocellulosic biomass based processes and the development and current status of various molecular engineering strategies to improve these processes.
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15
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Derntl C, Mach R, Mach-Aigner A. Application of the human estrogen receptor within a synthetic transcription factor in Trichoderma reesei. Fungal Biol Biotechnol 2020; 7:12. [PMID: 32765896 PMCID: PMC7396459 DOI: 10.1186/s40694-020-00102-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 07/17/2020] [Indexed: 12/28/2022] Open
Abstract
Background Synthetic gene expression systems offer a possibility for controllable and targeted induction of the expression of genes of interest, which is a fundamental technique necessary for basic research and industrial applications. The human estrogen receptor α contains a ligand binding domain that enforces dimerization and nuclear import upon binding of the inducer 17β-estradiol. In this study, we tested the potential of this ligand binding domain to be used in filamentous fungi as an auto-regulatory domain in a synthetic transcription factor. Results We constructed the synthetic transcription factor SynX by fusing the DNA-binding domain of Xyr1 (Xylanase Regulator 1), the transactivation domain of Ypr1 (Yellow Pigment Regulator 1), and the ligand binding domain of the human estrogen receptor α. SynX is able to strongly induce the gene expression of xylanases and an aldose reductase by addition of 17β-estradiol, but SynX does not induce gene expression of cellulases. Importantly, the induction of xylanase activities is mostly carbon source independent and can be fine-tuned by controlling the concentration of 17β-estradiol. Conclusion The ability of SynX to induce gene expression of xylanase encoding genes by addition of 17β-estradiol demonstrates that the ligand binding domain of the human estrogen receptor α works in filamentous fungi, and that it can be combined with a transactivation domain other than the commonly used transactivation domain of herpes simplex virion protein VP16.
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Affiliation(s)
- Christian Derntl
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Strasse 1a, 1060 Vienna, Austria
| | - Robert Mach
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Strasse 1a, 1060 Vienna, Austria
| | - Astrid Mach-Aigner
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Strasse 1a, 1060 Vienna, Austria
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16
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Daranagama ND, Suzuki Y, Shida Y, Ogasawara W. Involvement of Xyr1 and Are1 for Trichodermapepsin Gene Expression in Response to Cellulose and Galactose in Trichoderma reesei. Curr Microbiol 2020; 77:1506-1517. [DOI: 10.1007/s00284-020-01955-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 03/18/2020] [Indexed: 10/24/2022]
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17
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Zhang F, Li JX, Champreda V, Liu CG, Bai FW, Zhao XQ. Global Reprogramming of Gene Transcription in Trichoderma reesei by Overexpressing an Artificial Transcription Factor for Improved Cellulase Production and Identification of Ypr1 as an Associated Regulator. Front Bioeng Biotechnol 2020; 8:649. [PMID: 32719779 PMCID: PMC7351519 DOI: 10.3389/fbioe.2020.00649] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 05/27/2020] [Indexed: 12/29/2022] Open
Abstract
Synthetic biology studies on filamentous fungi are providing unprecedented opportunities for optimizing this important category of microbial cell factory. Artificial transcription factor can be designed and used to offer novel modes of regulation on gene transcription network. Trichoderma reesei is commonly used for cellulase production. In our previous studies, a plasmid library harboring genes encoding artificial zinc finger proteins (AZFPs) was constructed for engineering T. reesei, and the mutant strains with improved cellulase production were selected. However, the underlying mechanism by which AZFP function remain unclear. In this study, a T. reesei Rut-C30 mutant strain T. reesei U5 bearing an AZFP named as AZFP-U5 was focused, which secretes high level protein and shows significantly improved cellulase and xylanase production comparing with its parental strain. In addition, enhanced sugar release was achieved from lignocellulosic biomass using the crude cellulase from T. reesei U5. Comparative transcriptome analysis was further performed, which showed reprogramming of global gene transcription and elevated transcription of genes encoding glycoside hydrolases by overexpressing AZFP-U5. Furthermore, 15 candidate regulatory genes which showed remarkable higher transcription levels by AZFP-U5 insertion were overexpressed in T. reesei Rut-C30 to examine their effects on cellulase biosynthesis. Among these genes, TrC30_93861 (ypr1) and TrC30_74374 showed stimulating effects on filter paper activity (FPase), but deletion of these two genes did not affect cellulase activity. In addition, increased yellow pigment production in T. reesei Rut-C30 by overexpression of gene ypr1 was observed, and changes of cellulase gene transcription were revealed in the ypr1 deletion mutant, suggesting possible interaction between pigment production and cellulase gene transcription. The results in this study revealed novel aspects in regulation of cellulase gene expression by the artificial regulators. In addition, the candidate genes and processes identified in the transcriptome data can be further explored for synthetic biology design and metabolic engineering of T. reesei to enhance cellulase production.
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Affiliation(s)
- Fei Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Jia-Xiang Li
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Verawat Champreda
- Biorefinery and Bioproduct Research Group, Enzyme Technology Laboratory, National Center for Genetic Engineering and Biotechnology, Pathum Thani, Thailand
| | - Chen-Guang Liu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Feng-Wu Bai
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xin-Qing Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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Zhang T, Liu H, Lv B, Li C. Regulating Strategies for Producing Carbohydrate Active Enzymes by Filamentous Fungal Cell Factories. Front Bioeng Biotechnol 2020; 8:691. [PMID: 32733865 PMCID: PMC7360787 DOI: 10.3389/fbioe.2020.00691] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 06/03/2020] [Indexed: 12/17/2022] Open
Abstract
Filamentous fungi are important eukaryotic organisms crucial in substrate degradation and carbon cycle on the earth and have been harnessed as cell factories for the production of proteins and other high value-added products in recent decades. As cell factories, filamentous fungi play a crucial role in industrial protein production as both native hosts and heterologous hosts. In this review, the regulation strategies of carbohydrate active enzyme expression at both transcription level and protein level are introduced, and the transcription regulations are highlighted with induction mechanism, signaling pathway, and promoter and transcription factor regulation. Afterward, the regulation strategies in protein level including suitable posttranslational modification, protein secretion enhancement, and protease reduction are also presented. Finally, the challenges and perspectives in this field are discussed. In this way, a comprehensive knowledge regarding carbohydrate active enzyme production regulation at both transcriptional and protein levels is provided with the particular goal of aiding in the practical application of filamentous fungi for industrial protein production.
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Affiliation(s)
- Teng Zhang
- Institute for Synthetic Biosystem/Department of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Hu Liu
- Institute for Synthetic Biosystem/Department of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Bo Lv
- Institute for Synthetic Biosystem/Department of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Chun Li
- Institute for Synthetic Biosystem/Department of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Key Lab for Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, China
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Martins-Santana L, Paula RGD, Silva AG, Lopes DCB, Silva RDN, Silva-Rocha R. CRZ1 regulator and calcium cooperatively modulate holocellulases gene expression in Trichoderma reesei QM6a. Genet Mol Biol 2020; 43:e20190244. [PMID: 32384133 PMCID: PMC7212764 DOI: 10.1590/1678-4685-gmb-2019-0244] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 12/22/2019] [Indexed: 02/06/2023] Open
Abstract
Trichoderma reesei is the main filamentous fungus used in industry to produce cellulases. Here we investigated the role of CRZ1 and Ca2+signaling in the fungus T. reesei QM6a concerning holocellulases production. For this, we first searched for potential CRZ1 binding sites in promoter regions of key genes coding holocellulases, as well as transcriptional regulators and sugar and calcium transporters. Using a nearly constructed T. reeseiAcrz1 strain, we demonstrated that most of the genes expected to be regulated by CRZ1 were affected in the mutant strain induced with sugarcane bagasse (SCB) and cellulose. In particular, our data demonstrate that Ca2+ acts synergistically with CRZ1 to modulate gene expression, but also exerts CRZ1-independent regulatory role in gene expression in T. reesei, highlighting the role of the major regulator Ca2+ on the signaling for holocellulases transcriptional control in the most part of cellulases genes here investigated. This work presents new evidence on the regulatory role of CRZ1 and Ca2+ sensing in the regulation of cellulolytic enzymes in T. reesei, evidencing significant and previously unknown function of this Ca2+sensing system in the control key transcriptional regulators (XYR1 and CRE1) and on the expression of genes related to sugar and Ca2+ transport.
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Affiliation(s)
- Leonardo Martins-Santana
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Laboratório de Biologia Sistêmica e Sintética, Ribeirão Preto, SP, Brazil.,Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Bioquímica e Imunologia, Ribeirão Preto, SP, Brazil
| | - Renato Graciano de Paula
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Bioquímica e Imunologia, Ribeirão Preto, SP, Brazil.,Universidade Federal do Espírito Santo, Centro de Ciências da Saúde, Departamento de Ciências Fisiológicas, Vitória, ES, Brazil
| | - Adriano Gomes Silva
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Laboratório de Biologia Sistêmica e Sintética, Ribeirão Preto, SP, Brazil
| | - Douglas Christian Borges Lopes
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Bioquímica e Imunologia, Ribeirão Preto, SP, Brazil
| | - Roberto do Nascimento Silva
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Bioquímica e Imunologia, Ribeirão Preto, SP, Brazil
| | - Rafael Silva-Rocha
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Laboratório de Biologia Sistêmica e Sintética, Ribeirão Preto, SP, Brazil
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Xylanases from marine microorganisms: A brief overview on scope, sources, features and potential applications. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2020; 1868:140312. [DOI: 10.1016/j.bbapap.2019.140312] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 10/31/2019] [Accepted: 11/05/2019] [Indexed: 01/10/2023]
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21
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Beier S, Hinterdobler W, Bazafkan H, Schillinger L, Schmoll M. CLR1 and CLR2 are light dependent regulators of xylanase and pectinase genes in Trichoderma reesei. Fungal Genet Biol 2019; 136:103315. [PMID: 31816399 DOI: 10.1016/j.fgb.2019.103315] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 11/22/2019] [Accepted: 12/01/2019] [Indexed: 11/28/2022]
Abstract
Regulation of plant cell wall degradation is of utmost importance for understanding the carbon cycle in nature, but also to improve industrial processes aimed at enzyme production for next generation biofuels. Thereby, the transcription factor networks in different fungi show conservation as well as striking differences, particularly between Trichoderma reesei and Neurospora crassa. Here, we aimed to gain insight into the function of the transcription factors CLR1 and CLR2 in T. reesei, which are crucial for cellulase gene expression in N. crassa. We studied impacts on gene regulation with cellulose, xylan, pectin and chitin, growth on 95 different carbon sources as well as an involvement in regulation of secondary metabolism or development. We found that CLR1 is present in the genome of T. reesei and other Trichoderma spp., albeit with considerably lower homology compared to other ascomycetes. CLR1 and CLR2 regulate pectinase transcript levels upon growth on pectin, no major function was detected on chitin. CLR1 and CLR2 form a positive feedback cycle on xylan and were found to be responsible for balancing co-regulation of xylanase genes in light and darkness with distinct and in part opposite regulatory effects of up to 8fold difference. Our data suggest that CLR1 and CLR2 have evolved differently in T. reesei compared to other fungi. We propose a model in which their main function is in adjustment of regulation of xylanase gene expression to different light conditions and to balance transcript levels of genes involved in plant cell wall degradation according to their individual relevance for this process.
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Affiliation(s)
- Sabrina Beier
- AIT Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad Lorenz Strasse 24, 3430 Tulln, Austria.
| | - Wolfgang Hinterdobler
- AIT Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad Lorenz Strasse 24, 3430 Tulln, Austria.
| | - Hoda Bazafkan
- AIT Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad Lorenz Strasse 24, 3430 Tulln, Austria.
| | - Lukas Schillinger
- AIT Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad Lorenz Strasse 24, 3430 Tulln, Austria.
| | - Monika Schmoll
- AIT Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad Lorenz Strasse 24, 3430 Tulln, Austria.
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Derntl C, Mach RL, Mach-Aigner AR. Fusion transcription factors for strong, constitutive expression of cellulases and xylanases in Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:231. [PMID: 31583017 PMCID: PMC6767844 DOI: 10.1186/s13068-019-1575-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 09/22/2019] [Indexed: 05/07/2023]
Abstract
BACKGROUND The filamentous ascomycete T. reesei is industrially used to produce cellulases and xylanases. Cost-effective production of cellulases is a bottleneck for biofuel production. Previously, different strain and process optimizations were deployed to enhance enzyme production rates. One approach is the overexpression of the main activator Xyr1 and a second is the construction of synthetic transcription factors. Notably, these genetic manipulations were introduced into strains bearing the wild-type xyr1 gene and locus. RESULTS Here, we constructed a Xyr1-deficient strain expressing a non-functional truncated version of Xyr1. This strain was successfully used as platform strain for overexpression of Xyr1, which enhanced the cellulase and xylanase production rates under inducing conditions, with the exception of lactose-there the cellulase production was severely reduced. Further, we introduced fusion transcription factors consisting of the DNA-binding domain of Xyr1 and the transactivation domain of either Ypr1 or Ypr2 (regulators of the sorbicillinoid biosynthesis gene cluster). The fusion of Xyr1 and Ypr2 yielded a moderately transactivating transcription factor, whereas the fusion of Xyr1 and Ypr1 yielded a highly transactivating transcription factor that induced xylanases and cellulases nearly carbon source independently. Especially, high production levels of xylanases were achieved on glycerol. CONCLUSION During this study, we constructed a Xyr1-deficient strain that can be fully reconstituted, which makes it an ideal platform strain for Xyr1-related studies. The mere overexpression of Xyr1 turned out not to be a successful strategy for overall enhancement of the enzyme production rates. We gained new insights into the regulatory properties of transcription factors by constructing respective fusion proteins. The Xyr1-Ypr1-fusion transcription factor could induce xylanase production rates on glycerol to outstanding extents, and hence could be deployed in the future to utilize crude glycerol, the main co-product of the biodiesel production process.
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Affiliation(s)
- Christian Derntl
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Strasse 1a, 1060 Vienna, Austria
| | - Robert L. Mach
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Strasse 1a, 1060 Vienna, Austria
| | - Astrid R. Mach-Aigner
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Strasse 1a, 1060 Vienna, Austria
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Protein phosphatases regulate growth, development, cellulases and secondary metabolism in Trichoderma reesei. Sci Rep 2019; 9:10995. [PMID: 31358805 PMCID: PMC6662751 DOI: 10.1038/s41598-019-47421-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 07/03/2019] [Indexed: 12/15/2022] Open
Abstract
Trichoderma reesei represents one of the most prolific producers of plant cell wall degrading enzymes. Recent research showed broad regulation by phosphorylation in T. reesei, including important transcription factors involved in cellulase regulation. To evaluate factors crucial for changes in these phosphorylation events, we studied non-essential protein phosphatases (PPs) of T. reesei. Viable deletion strains were tested for growth on different carbon sources, osmotic and oxidative stress response, asexual and sexual development, cellulase and protease production as well as secondary metabolism. Six PPs were found to be positive or negative regulators for cellulase production. A correlation of the effects of PPs on protease activities and cellulase activities was not detected. Hierarchical clustering of regulation patterns and phenotypes of deletion indicated functional specialization within PP classes and common as well as variable effects. Our results confirmed the central role of catalytic and regulatory subunits of PP2A which regulates several aspects of cell growth and metabolism. Moreover we show that the additional homologue of PPH5 in Trichoderma spp., PPH5-2 assumes distinct functions in metabolism, development and stress response, different from PPH5. The influence of PPs on both cellulase gene expression and secondary metabolite production support an interrelationship in the underlying regulation mechanisms.
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A Novel Cys2His2 Zinc Finger Homolog of AZF1 Modulates Holocellulase Expression in Trichoderma reesei. mSystems 2019; 4:4/4/e00161-19. [PMID: 31213522 PMCID: PMC6581689 DOI: 10.1128/msystems.00161-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this work, we used a systems biology approach to map new regulatory interactions in Trichoderma reesei controlling the expression of genes encoding cellulase and hemicellulase. By integrating transcriptomics related to complex biomass degradation, we were able to identify a novel transcriptional regulator which is able to activate the expression of these genes in response to two different cellulose sources. In vivo experimental validation confirmed the role of this new regulator in several other processes related to carbon source utilization and nutrient transport. Therefore, this work revealed novel forms of regulatory interaction in this model system for plant biomass deconstruction and also represented a new approach that could be easy applied to other organisms. Filamentous fungi are remarkable producers of enzymes dedicated to the degradation of sugar polymers found in the plant cell wall. Here, we integrated transcriptomic data to identify novel transcription factors (TFs) related to the control of gene expression of lignocellulosic hydrolases in Trichoderma reesei and Aspergillus nidulans. Using various sets of differentially expressed genes, we identified some putative cis-regulatory elements that were related to known binding sites for Saccharomyces cerevisiae TFs. Comparative genomics allowed the identification of six transcriptional factors in filamentous fungi that have corresponding S. cerevisiae homologs. Additionally, a knockout strain of T. reesei lacking one of these TFs (S. cerevisiaeAZF1 homolog) displayed strong reductions in the levels of expression of several cellulase-encoding genes in response to both Avicel and sugarcane bagasse, revealing a new player in the complex regulatory network operating in filamentous fungi during plant biomass degradation. Finally, RNA sequencing (RNA-seq) analysis showed the scope of the AZF1 homologue in regulating a number of processes in T. reesei, and chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR) provided evidence for the direct interaction of this TF in the promoter regions of cel7a, cel45a, and swo. Therefore, we identified here a novel TF which plays a positive effect in the expression of cellulase-encoding genes in T. reesei. IMPORTANCE In this work, we used a systems biology approach to map new regulatory interactions in Trichoderma reesei controlling the expression of genes encoding cellulase and hemicellulase. By integrating transcriptomics related to complex biomass degradation, we were able to identify a novel transcriptional regulator which is able to activate the expression of these genes in response to two different cellulose sources. In vivo experimental validation confirmed the role of this new regulator in several other processes related to carbon source utilization and nutrient transport. Therefore, this work revealed novel forms of regulatory interaction in this model system for plant biomass deconstruction and also represented a new approach that could be easy applied to other organisms.
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Hitzenhammer E, Büschl C, Sulyok M, Schuhmacher R, Kluger B, Wischnitzki E, Schmoll M. YPR2 is a regulator of light modulated carbon and secondary metabolism in Trichoderma reesei. BMC Genomics 2019; 20:211. [PMID: 30866811 PMCID: PMC6417087 DOI: 10.1186/s12864-019-5574-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 02/28/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Filamentous fungi have evolved to succeed in nature by efficient growth and degradation of substrates, but also due to the production of secondary metabolites including mycotoxins. For Trichoderma reesei, as a biotechnological workhorse for homologous and heterologous protein production, secondary metabolite secretion is of particular importance for industrial application. Recent studies revealed an interconnected regulation of enzyme gene expression and carbon metabolism with secondary metabolism. RESULTS Here, we investigated gene regulation by YPR2, one out of two transcription factors located within the SOR cluster of T. reesei, which is involved in biosynthesis of sorbicillinoids. Transcriptome analysis showed that YPR2 exerts its major function in constant darkness upon growth on cellulose. Targets (direct and indirect) of YPR2 overlap with induction specific genes as well as with targets of the carbon catabolite repressor CRE1 and a considerable proportion is regulated by photoreceptors as well. Functional category analysis revealed both effects on carbon metabolism and secondary metabolism. Further, we found indications for an involvement of YPR2 in regulation of siderophores. In agreement with transcriptome data, mass spectrometric analyses revealed a broad alteration in metabolite patterns in ∆ypr2. Additionally, YPR2 positively influenced alamethicin levels along with transcript levels of the alamethicin synthase tex1 and is essential for production of orsellinic acid in darkness. CONCLUSIONS YPR2 is an important regulator balancing secondary metabolism with carbon metabolism in darkness and depending on the carbon source. The function of YPR2 reaches beyond the SOR cluster in which ypr2 is located and happens downstream of carbon catabolite repression mediated by CRE1.
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Affiliation(s)
- Eva Hitzenhammer
- AIT - Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad-Lorenz-Strasse 24, 3430 Tulln, Austria
| | - Christoph Büschl
- Department of Agrobiotechnology (IFA-Tulln), Center for Analytical Chemistry, University of Natural Resources and Life Sciences Vienna, (BOKU), Konrad-Lorenz-Straße 20, 3430 Tulln, Austria
| | - Michael Sulyok
- Department of Agrobiotechnology (IFA-Tulln), Center for Analytical Chemistry, University of Natural Resources and Life Sciences Vienna, (BOKU), Konrad-Lorenz-Straße 20, 3430 Tulln, Austria
| | - Rainer Schuhmacher
- Department of Agrobiotechnology (IFA-Tulln), Center for Analytical Chemistry, University of Natural Resources and Life Sciences Vienna, (BOKU), Konrad-Lorenz-Straße 20, 3430 Tulln, Austria
| | - Bernhard Kluger
- Department of Agrobiotechnology (IFA-Tulln), Center for Analytical Chemistry, University of Natural Resources and Life Sciences Vienna, (BOKU), Konrad-Lorenz-Straße 20, 3430 Tulln, Austria
| | - Elisabeth Wischnitzki
- AIT - Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad-Lorenz-Strasse 24, 3430 Tulln, Austria
| | - Monika Schmoll
- AIT - Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad-Lorenz-Strasse 24, 3430 Tulln, Austria
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26
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Alazi E, Ram AFJ. Modulating Transcriptional Regulation of Plant Biomass Degrading Enzyme Networks for Rational Design of Industrial Fungal Strains. Front Bioeng Biotechnol 2018; 6:133. [PMID: 30320082 PMCID: PMC6167437 DOI: 10.3389/fbioe.2018.00133] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 09/05/2018] [Indexed: 01/08/2023] Open
Abstract
Filamentous fungi are the most important microorganisms for the industrial production of plant polysaccharide degrading enzymes due to their unique ability to secrete these proteins efficiently. These carbohydrate active enzymes (CAZymes) are utilized industrially for the hydrolysis of plant biomass for the subsequent production of biofuels and high-value biochemicals. The expression of the genes encoding plant biomass degrading enzymes is tightly controlled. Naturally, large amounts of CAZymes are produced and secreted only in the presence of the plant polysaccharide they specifically act on. The signal to produce is conveyed via so-called inducer molecules which are di- or mono-saccharides (or derivatives thereof) released from the specific plant polysaccharides. The presence of the inducer results in the activation of a substrate-specific transcription factor (TF), which is required not only for the controlled expression of the genes encoding the CAZymes, but often also for the regulation of the expression of the genes encoding sugar transporters and catabolic pathway enzymes needed to utilize the released monosaccharide. Over the years, several substrate-specific TFs involved in the degradation of cellulose, hemicellulose, pectin, starch and inulin have been identified in several fungal species and systems biology approaches have made it possible to uncover the enzyme networks controlled by these TFs. The requirement for specific inducers for TF activation and subsequently the expression of particular enzyme networks determines the choice of feedstock to produce enzyme cocktails for industrial use. It also results in batch-to-batch variation in the composition and amounts of enzymes due to variations in sugar composition and polysaccharide decorations of the feedstock which hampers the use of cheap feedstocks for constant quality of enzyme cocktails. It is therefore of industrial interest to produce specific enzyme cocktails constitutively and independently of inducers. In this review, we focus on the methods to modulate TF activities for inducer-independent production of CAZymes and highlight various approaches that are used to construct strains displaying constitutive expression of plant biomass degrading enzyme networks. These approaches and combinations thereof are also used to construct strains displaying increased expression of CAZymes under inducing conditions, and make it possible to design strains in which different enzyme mixtures are simultaneously produced independently of the carbon source.
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Affiliation(s)
| | - Arthur F. J. Ram
- Molecular Microbiology and Biotechnology, Institute of Biology Leiden, Leiden University, Leiden, Netherlands
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27
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Hirasawa H, Shioya K, Furukawa T, Tani S, Sumitani JI, Kawaguchi T, Morikawa Y, Shida Y, Ogasawara W. Engineering of the Trichoderma reesei xylanase3 promoter for efficient enzyme expression. Appl Microbiol Biotechnol 2018; 102:2737-2752. [DOI: 10.1007/s00253-018-8763-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Revised: 12/21/2017] [Accepted: 01/09/2018] [Indexed: 12/15/2022]
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28
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Adnan M, Zheng W, Islam W, Arif M, Abubakar YS, Wang Z, Lu G. Carbon Catabolite Repression in Filamentous Fungi. Int J Mol Sci 2017; 19:ijms19010048. [PMID: 29295552 PMCID: PMC5795998 DOI: 10.3390/ijms19010048] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 12/13/2017] [Accepted: 12/20/2017] [Indexed: 12/18/2022] Open
Abstract
Carbon Catabolite Repression (CCR) has fascinated scientists and researchers around the globe for the past few decades. This important mechanism allows preferential utilization of an energy-efficient and readily available carbon source over relatively less easily accessible carbon sources. This mechanism helps microorganisms to obtain maximum amount of glucose in order to keep pace with their metabolism. Microorganisms assimilate glucose and highly favorable sugars before switching to less-favored sources of carbon such as organic acids and alcohols. In CCR of filamentous fungi, CreA acts as a transcription factor, which is regulated to some extent by ubiquitination. CreD-HulA ubiquitination ligase complex helps in CreA ubiquitination, while CreB-CreC deubiquitination (DUB) complex removes ubiquitin from CreA, which causes its activation. CCR of fungi also involves some very crucial elements such as Hexokinases, cAMP, Protein Kinase (PKA), Ras proteins, G protein-coupled receptor (GPCR), Adenylate cyclase, RcoA and SnfA. Thorough study of molecular mechanism of CCR is important for understanding growth, conidiation, virulence and survival of filamentous fungi. This review is a comprehensive revision of the regulation of CCR in filamentous fungi as well as an updated summary of key regulators, regulation of different CCR-dependent mechanisms and its impact on various physical characteristics of filamentous fungi.
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Affiliation(s)
- Muhammad Adnan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Key Laboratory of Bio-Pesticides and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Wenhui Zheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Key Laboratory of Bio-Pesticides and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Waqar Islam
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Muhammad Arif
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Yakubu Saddeeq Abubakar
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Key Laboratory of Bio-Pesticides and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Zonghua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Key Laboratory of Bio-Pesticides and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Guodong Lu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Key Laboratory of Bio-Pesticides and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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Li Z, Liu G, Qu Y. Improvement of cellulolytic enzyme production and performance by rational designing expression regulatory network and enzyme system composition. BIORESOURCE TECHNOLOGY 2017; 245:1718-1726. [PMID: 28684177 DOI: 10.1016/j.biortech.2017.06.120] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/19/2017] [Accepted: 06/20/2017] [Indexed: 06/07/2023]
Abstract
Filamentous fungi are considered as the most efficient producers expressing lignocellulose-degrading enzymes. Penicillium oxalicum strains possess extraordinary fungal lignocellulolytic enzyme systems and can efficiently utilize plant biomass. In recent years, the regulatory aspects of production of hydrolytic enzymes by P. oxalicum have been well established. This review aims to discuss the recent developments for the production of lignocellulolytic enzymes by P. oxalicum. The main cellulolytic transcription factors mediating the complex transcriptional-regulatory network are highlighted. The genome-wide identification of cellulolytic transcription factors, the cascade regulation network for cellulolytic gene expression, and the synergistic and dose-controlled regulation by cellulolytic regulators are discussed. A cellulase regulatory network sensitive to inducers in intracellular environments, the cross-talk of regulation of lignocellulose-degrading enzyme and amylase, and accessory enzymes are also demonstrated. Finally, strategies for the metabolic engineering of P. oxalicum, which show promising applications in the enzymatic hydrolysis for biochemical production, are established.
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Affiliation(s)
- Zhonghai Li
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China; Shandong Provincial Key Laboratory of Microbial Engineering, Department of Bioengineering, Qi Lu University of Technology, Jinan 250353, China
| | - Guodong Liu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China.
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Light, stress, sex and carbon - The photoreceptor ENVOY as a central checkpoint in the physiology of Trichoderma reesei. Fungal Biol 2017; 122:479-486. [PMID: 29801792 DOI: 10.1016/j.funbio.2017.10.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/11/2017] [Accepted: 10/18/2017] [Indexed: 12/20/2022]
Abstract
Trichoderma reesei represents one of the most prolific producers of homologous and heterologous proteins. Discovery of the photoreceptor ENV1 as a regulator of cellulase gene expression initiated analysis of light response pathways and their physiological relevance for T. reesei. The function of ENV1 in regulation of plant cell wall degrading enzymes is conserved in Neurospora crassa. ENV1 emerged as a central checkpoint for integration of nutrient sensing, light response and development. This photoreceptor exerts its function by influencing transcript abundance and feedback cycles of the alpha subunits of the heterotrimeric G-protein pathway and impacts regulation of the beta and gamma subunits via mutual regulation with the phosducin PhLP1. The output of regulation by ENV1 is in part mediated by the cAMP pathway and likely aimed at cellulose recognition. Lack of ENV1 causes deregulation of the pheromone system and female sterility in light. A regulatory interconnection with VEL1 and influence on other regulators of secondary metabolism like YPR2 as well as polyketide synthase encoding genes indicates a function in secondary metabolism. The function of ENV1 in integrating light response with signaling of osmotic and oxidative stress is evolutionary conserved in Hypocreales and distinct from other sordariomycetes including N. crassa.
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Monroy AA, Stappler E, Schuster A, Sulyok M, Schmoll M. A CRE1- regulated cluster is responsible for light dependent production of dihydrotrichotetronin in Trichoderma reesei. PLoS One 2017; 12:e0182530. [PMID: 28809958 PMCID: PMC5557485 DOI: 10.1371/journal.pone.0182530] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 07/19/2017] [Indexed: 02/08/2023] Open
Abstract
Changing light conditions, caused by the rotation of earth resulting in day and night or growth on the surface or within a substrate, result in considerably altered physiological processes in fungi. For the biotechnological workhorse Trichoderma reesei, regulation of glycoside hydrolase gene expression, especially cellulase expression was shown to be a target of light dependent gene regulation. Analysis of regulatory targets of the carbon catabolite repressor CRE1 under cellulase inducing conditions revealed a secondary metabolite cluster to be differentially regulated in light and darkness and by photoreceptors. We found that this cluster is involved in production of trichodimerol and that the two polyketide synthases of the cluster are essential for biosynthesis of dihydrotrichotetronine (syn. bislongiquinolide or bisorbibutenolide). Additionally, an indirect influence on production of the peptaibol antibiotic paracelsin was observed. The two polyketide synthetase genes as well as the monooxygenase gene of the cluster were found to be connected at the level of transcription in a positive feedback cycle in darkness, but negative feedback in light, indicating a cellular sensing and response mechanism for the products of these enzymes. The transcription factor TR_102497/YPR2 residing within the cluster regulates the cluster genes in a light dependent manner. Additionally, an interrelationship of this cluster with regulation of cellulase gene expression was detected. Hence the regulatory connection between primary and secondary metabolism appears more widespread than previously assumed, indicating a sophisticated distribution of resources either to degradation of substrate (feed) or to antagonism of competitors (fight), which is influenced by light.
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Affiliation(s)
- Alberto Alonso Monroy
- AIT - Austrian Institute of Technology GmbH, Center for Health & Bioresources, Tulln, Austria
| | - Eva Stappler
- AIT - Austrian Institute of Technology GmbH, Center for Health & Bioresources, Tulln, Austria
| | - Andre Schuster
- TU Wien, Institute of Chemical Engineering, Research Area Molecular Biotechnology, Vienna, Austria
| | - Michael Sulyok
- University of Natural Resources and Life Sciences Vienna, Department for Agrobiotechnology (IFA-Tulln), Center for Analytical Chemistry, Tulln, Austria
| | - Monika Schmoll
- AIT - Austrian Institute of Technology GmbH, Center for Health & Bioresources, Tulln, Austria
- * E-mail:
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32
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Borin GP, Sanchez CC, de Santana ES, Zanini GK, Dos Santos RAC, de Oliveira Pontes A, de Souza AT, Dal'Mas RMMTS, Riaño-Pachón DM, Goldman GH, Oliveira JVDC. Comparative transcriptome analysis reveals different strategies for degradation of steam-exploded sugarcane bagasse by Aspergillus niger and Trichoderma reesei. BMC Genomics 2017; 18:501. [PMID: 28666414 PMCID: PMC5493111 DOI: 10.1186/s12864-017-3857-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 06/09/2017] [Indexed: 12/12/2022] Open
Abstract
Background Second generation (2G) ethanol is produced by breaking down lignocellulosic biomass into fermentable sugars. In Brazil, sugarcane bagasse has been proposed as the lignocellulosic residue for this biofuel production. The enzymatic cocktails for the degradation of biomass-derived polysaccharides are mostly produced by fungi, such as Aspergillus niger and Trichoderma reesei. However, it is not yet fully understood how these microorganisms degrade plant biomass. In order to identify transcriptomic changes during steam-exploded bagasse (SEB) breakdown, we conducted a RNA-seq comparative transcriptome profiling of both fungi growing on SEB as carbon source. Results Particular attention was focused on CAZymes, sugar transporters, transcription factors (TFs) and other proteins related to lignocellulose degradation. Although genes coding for the main enzymes involved in biomass deconstruction were expressed by both fungal strains since the beginning of the growth in SEB, significant differences were found in their expression profiles. The expression of these enzymes is mainly regulated at the transcription level, and A. niger and T. reesei also showed differences in TFs content and in their expression. Several sugar transporters that were induced in both fungal strains could be new players on biomass degradation besides their role in sugar uptake. Interestingly, our findings revealed that in both strains several genes that code for proteins of unknown function and pro-oxidant, antioxidant, and detoxification enzymes were induced during growth in SEB as carbon source, but their specific roles on lignocellulose degradation remain to be elucidated. Conclusions This is the first report of a time-course experiment monitoring the degradation of pretreated bagasse by two important fungi using the RNA-seq technology. It was possible to identify a set of genes that might be applied in several biotechnology fields. The data suggest that these two microorganisms employ different strategies for biomass breakdown. This knowledge can be exploited for the rational design of enzymatic cocktails and 2G ethanol production improvement. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3857-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gustavo Pagotto Borin
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Av Giuseppe Maximo Scolfaro 10000, Campinas, São Paulo, Caixa Postal 6170, 13083-970, Brazil
| | - Camila Cristina Sanchez
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Av Giuseppe Maximo Scolfaro 10000, Campinas, São Paulo, Caixa Postal 6170, 13083-970, Brazil
| | - Eliane Silva de Santana
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Av Giuseppe Maximo Scolfaro 10000, Campinas, São Paulo, Caixa Postal 6170, 13083-970, Brazil
| | - Guilherme Keppe Zanini
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Av Giuseppe Maximo Scolfaro 10000, Campinas, São Paulo, Caixa Postal 6170, 13083-970, Brazil
| | - Renato Augusto Corrêa Dos Santos
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Av Giuseppe Maximo Scolfaro 10000, Campinas, São Paulo, Caixa Postal 6170, 13083-970, Brazil
| | - Angélica de Oliveira Pontes
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Av Giuseppe Maximo Scolfaro 10000, Campinas, São Paulo, Caixa Postal 6170, 13083-970, Brazil
| | - Aline Tieppo de Souza
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Av Giuseppe Maximo Scolfaro 10000, Campinas, São Paulo, Caixa Postal 6170, 13083-970, Brazil
| | - Roberta Maria Menegaldo Tavares Soares Dal'Mas
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Av Giuseppe Maximo Scolfaro 10000, Campinas, São Paulo, Caixa Postal 6170, 13083-970, Brazil
| | - Diego Mauricio Riaño-Pachón
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Av Giuseppe Maximo Scolfaro 10000, Campinas, São Paulo, Caixa Postal 6170, 13083-970, Brazil.,Current address: Laboratório de Biologia de Sistemas Regulatórios, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes, 748 - Butantã - São Paulo - SP, São Paulo, CEP 05508-000, Brazil
| | - Gustavo Henrique Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av do Café S/N, Ribeirão Preto, CEP, São Paulo, 14040-903, Brazil
| | - Juliana Velasco de Castro Oliveira
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Av Giuseppe Maximo Scolfaro 10000, Campinas, São Paulo, Caixa Postal 6170, 13083-970, Brazil.
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Transcription factor Xpp1 is a switch between primary and secondary fungal metabolism. Proc Natl Acad Sci U S A 2017; 114:E560-E569. [PMID: 28074041 DOI: 10.1073/pnas.1609348114] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Fungi can produce a wide range of chemical compounds via secondary metabolism. These compounds are of major interest because of their (potential) application in medicine and biotechnology and as a potential source for new therapeutic agents and drug leads. However, under laboratory conditions, most secondary metabolism genes remain silent. This circumstance is an obstacle for the production of known metabolites and the discovery of new secondary metabolites. In this study, we describe the dual role of the transcription factor Xylanase promoter binding protein 1 (Xpp1) in the regulation of both primary and secondary metabolism of Trichoderma reesei Xpp1 was previously described as a repressor of xylanases. Here, we provide data from an RNA-sequencing analysis suggesting that Xpp1 is an activator of primary metabolism. This finding is supported by our results from a Biolog assay determining the carbon source assimilation behavior of an xpp1 deletion strain. Furthermore, the role of Xpp1 as a repressor of secondary metabolism is shown by gene expression analyses of polyketide synthases and the determination of the secondary metabolites of xpp1 deletion and overexpression strains using an untargeted metabolomics approach. The deletion of Xpp1 resulted in the enhanced secretion of secondary metabolites in terms of diversity and quantity. Homologs of Xpp1 are found among a broad range of fungi, including the biocontrol agent Trichoderma atroviride, the plant pathogens Fusarium graminearum and Colletotrichum graminicola, the model organism Neurospora crassa, the human pathogen Sporothrix schenckii, and the ergot fungus Claviceps purpurea.
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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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Benocci T, Aguilar-Pontes MV, Zhou M, Seiboth B, de Vries RP. Regulators of plant biomass degradation in ascomycetous fungi. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:152. [PMID: 28616076 PMCID: PMC5468973 DOI: 10.1186/s13068-017-0841-x] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 06/06/2017] [Indexed: 05/05/2023]
Abstract
Fungi play a major role in the global carbon cycle because of their ability to utilize plant biomass (polysaccharides, proteins, and lignin) as carbon source. Due to the complexity and heterogenic composition of plant biomass, fungi need to produce a broad range of degrading enzymes, matching the composition of (part of) the prevalent substrate. This process is dependent on a network of regulators that not only control the extracellular enzymes that degrade the biomass, but also the metabolic pathways needed to metabolize the resulting monomers. This review will summarize the current knowledge on regulation of plant biomass utilization in fungi and compare the differences between fungal species, focusing in particular on the presence or absence of the regulators involved in this process.
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Affiliation(s)
- Tiziano Benocci
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Maria Victoria Aguilar-Pontes
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Miaomiao Zhou
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Bernhard Seiboth
- Research Area Biochemical Technology, Institute of Chemical and Biological Engineering, TU Wien, 1060 Vienna, Austria
| | - Ronald P. de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
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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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Shida Y, Furukawa T, Ogasawara W. Deciphering the molecular mechanisms behind cellulase production in Trichoderma reesei, the hyper-cellulolytic filamentous fungus. Biosci Biotechnol Biochem 2016; 80:1712-29. [DOI: 10.1080/09168451.2016.1171701] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Abstract
The filamentous fungus Trichoderma reesei is a potent cellulase producer and the best-studied cellulolytic fungus. A lot of investigations not only on glycoside hydrolases produced by T. reesei, but also on the machinery controlling gene expression of these enzyme have made this fungus a model organism for cellulolytic fungi. We have investigated the T. reesei strain including mutants developed in Japan in detail to understand the molecular mechanisms that control the cellulase gene expression, the biochemical and morphological aspects that could favor this phenotype, and have attempted to generate novel strains that may be appropriate for industrial use. Subsequently, we developed recombinant strains by combination of these insights and the heterologous-efficient saccharifing enzymes. Resulting enzyme preparations were highly effective for saccharification of various biomass. In this review, we present some of the salient findings from the recent biochemical, morphological, and molecular analyses of this remarkable cellulase hyper-producing fungus.
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Affiliation(s)
- Yosuke Shida
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Japan
| | - Takanori Furukawa
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Japan
| | - Wataru Ogasawara
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Japan
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The Post-genomic Era of Trichoderma reesei: What's Next? Trends Biotechnol 2016; 34:970-982. [PMID: 27394390 DOI: 10.1016/j.tibtech.2016.06.003] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 06/09/2016] [Accepted: 06/13/2016] [Indexed: 11/21/2022]
Abstract
The ascomycete Trichoderma reesei is one of the most well studied cellulolytic microorganisms. This fungus is widely used in the biotechnology industry, mainly in the production of biofuels. Due to its importance, its genome was sequenced in 2008, opening new avenues to study this microorganism. In this 'post-genomic' era, a transcriptomic and proteomic era has emerged. Here, we present an overview of new findings in the gene expression regulation network of T. reesei. We also discuss new rational strategies to obtain mutants that produce hydrolytic enzymes with a higher yield, using metabolic engineering. Finally, we present how synthetic biology strategies can be used to create engineered promoters to efficiently synthesize enzymes for biomass degradation to produce bioethanol.
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Druzhinina IS, Kubicek CP. Familiar Stranger: Ecological Genomics of the Model Saprotroph and Industrial Enzyme Producer Trichoderma reesei Breaks the Stereotypes. ADVANCES IN APPLIED MICROBIOLOGY 2016; 95:69-147. [PMID: 27261782 DOI: 10.1016/bs.aambs.2016.02.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The filamentous fungus Trichoderma reesei (Hypocreales, Ascomycota) has properties of an efficient cell factory for protein production that is exploited by the enzyme industry, particularly with respect to cellulase and hemicellulase formation. Under conditions of industrial fermentations it yields more than 100g secreted protein L(-1). Consequently, T. reesei has been intensively studied in the 20th century. Most of these investigations focused on the biochemical characteristics of its cellulases and hemicellulases, on the improvement of their properties by protein engineering, and on enhanced enzyme production by recombinant strategies. However, as the fungus is rare in nature, its ecology remained unknown. The breakthrough in the understanding of the fundamental biology of T. reesei only happened during 2000s-2010s. In this review, we compile the current knowledge on T. reesei ecology, physiology, and genomics to present a holistic view on the natural behavior of the organism. This is not only critical for science-driven further improvement of the biotechnological applications of this fungus, but also renders T. reesei as an attractive model of filamentous fungi with superior saprotrophic abilities.
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Affiliation(s)
- I S Druzhinina
- Institute of Chemical Engineering, TU Wien, Vienna, Austria
| | - C P Kubicek
- Institute of Chemical Engineering, TU Wien, Vienna, Austria
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