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Randhawa A, A Ogunyewo O, Jawed K, Yazdani SS. Calcium signaling positively regulates cellulase translation and secretion in a Clr-2-overexpressing, catabolically derepressed strain of Penicillium funiculosum. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:21. [PMID: 38336687 PMCID: PMC10858516 DOI: 10.1186/s13068-023-02448-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Accepted: 12/13/2023] [Indexed: 02/12/2024]
Abstract
BACKGROUND Low-cost cellulase production is vital to sustainable second-generation biorefineries. The catabolically derepressed strain of Penicillium funiculosum NCIM1228 (PfMig188 or ∆Mig1) secretes a superior set of cellulolytic enzymes, that are most suitable for 2G biorefineries. At a 3% (w/w) load, the ∆Mig1 secretome can release > 80% of fermentable sugars from lignocellulose at a 15% (w/v) biomass load, irrespective of the type of biomass and pretreatment. The robustness of the secretome can be further increased by improving the cellulase production capacity of the fungal strain. RESULTS We began by identifying the transcription factor responsible for cellulase production in NCIM1228. An advanced RNA-seq screen identified three genes, clr-2, ctf1a and ctf1b; the genes were cloned under their native promoters and transformed into NCIM1228. Of the three, clr-2 overexpression led to twofold higher cellulase production than the parent strain and was thus identified as the transcriptional activator of cellulase in NCIM1228. Next, we overexpressed clr-2 in ∆Mig1 and expected an exponential increase in cellulolytic attributes accredited to the reinforced activation mechanisms, conjoint with diminished negative regulation. Although clr-2 overexpression increased the transcript levels of cellulase genes in ∆Mig1, there was no increase in cellulase yield. Even a further increase in the transcript levels of clr-2 via a stronger promoter was ineffective. However, when the CaCO3 concentration was increased to 5 g/l in the growth medium, we achieved a 1.5-fold higher activity of 6.4 FPU/ml in the ∆Mig1 strain with clr-2 overexpression. Enthused by the calcium effect, a transcriptomic screen for genes encoding Ca2+-activated kinase identified ssp1, whose overexpression could further increase cellulase yield to ~ 7.5 FPU/ml. Investigation of the mechanism revealed that calcium signaling exclusively enhances the translation and secretion of cellulase in Penicillium funiculosum. CONCLUSIONS Our study identifies for the first time that cellulose activates two discrete signaling events to govern cellulase transcription and posttranscriptional processes (translation, processing and secretion) in P. funiculosum NCIM1228. Whereas Clr-2, the transcriptional activator of cellulase, governs transcription, calcium signaling specifically activates cellulase translation and secretion.
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Affiliation(s)
- Anmoldeep Randhawa
- Microbial Engineering Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, 110067, India.
- DBT-ICGEB Centre for Advanced Bioenergy Research, International Centre for Genetic Engineering and Biotechnology, New Delhi, 110067, India.
- AMITY University, Mohali, Punjab, 140306, India.
| | - Olusola A Ogunyewo
- Microbial Engineering Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, 110067, India
| | - Kamran Jawed
- Microbial Engineering Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, 110067, India
| | - Syed Shams Yazdani
- Microbial Engineering Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, 110067, India.
- DBT-ICGEB Centre for Advanced Bioenergy Research, International Centre for Genetic Engineering and Biotechnology, New Delhi, 110067, India.
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Xia C, Qi X, Song X. Cumulative expression of heterologous XlnR regulatory modules and AraR A731V in Penicillium oxalicum enhances saccharification efficiency of corn stover and corn fiber. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:18. [PMID: 38303075 PMCID: PMC10835966 DOI: 10.1186/s13068-024-02464-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 01/18/2024] [Indexed: 02/03/2024]
Abstract
Penicillium oxalicum engineered strain DB2 and its mutant strains with multiple regulatory modules were constructed. Mutant strain RE-4-2 with two regulatory modules showed a significant increase in the reducing sugar released from corn stover and corn fiber as well as in the conversion of cellulose than DB2. RE-5-2 with three regulatory modules showed a further increase in reducing sugar released from corn stover and the conversion of cellulose on the basis of RE-4-2. RE-4-2-AraRA731V constructed by overexpressing AraRA731V in RE-4-2 showed an increase of 7.2 times and 1.2 times in arabinofuranosidase and xylosidase activities, respectively. Reducing sugar yield and cellulose conversion of corn stover and corn fiber by RE-4-2-AraRA731V were further increased.
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Affiliation(s)
- Chengqiang Xia
- College of Animal Science, Shanxi Agriculture University, Minxiannan Road 1, Jinzhong, 030801, Shanxi, China
| | - Xiaoyu Qi
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, 250100, Shandong, China
| | - Xin Song
- State Key Laboratory of Microbial Technology, Shandong University, Binhai Road 72, Qingdao, 266237, Shandong, People's Republic of China.
- National Glycoengineering Research Center, Shandong University, Binhai Road 72, Qingdao, 266237, Shandong, People's Republic of China.
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3
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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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Chen M, Liu Y, Liu Z, Su L, Yan L, Huang Y, Huang Y, Zhang W, Xu X, Zheng F. Histone acetyltransferase Gcn5-mediated histone H3 acetylation facilitates cryptococcal morphogenesis and sexual reproduction. mSphere 2023; 8:e0029923. [PMID: 37850793 PMCID: PMC10732044 DOI: 10.1128/msphere.00299-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 09/08/2023] [Indexed: 10/19/2023] Open
Abstract
IMPORTANCE Eukaryotic gene transcription is typically regulated by a series of histone modifications, which play a crucial role in adapting to complex environmental stresses. In the ubiquitous human fungal pathogen Cryptococcus neoformans, sexual life cycle is a continuous intracellular differentiation process that strictly occurs in response to mating stimulation. Despite the comprehensive identification of the regulatory factors and genetic pathways involved in its sexual cycle, understanding of the epigenetic modifications involved in this process remains quite limited. In this research, we found that histone acetyltransferase Gcn5-mediated histone H3 acetylation plays a crucial role in completing the cryptococcal sexual cycle, including yeast-hyphae morphogenesis and the subsequent sexual reproduction. Furthermore, we demonstrated that Gcn5 participates in this process primarily through regulating the key morphogenesis regulator Znf2 and its targets. This study thus provided a comprehensive understanding of how histone acetylation modification impacts sexual life cycle in a high-risk human pathogenic fungus.
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Affiliation(s)
- Man Chen
- Department of Respiratory Medicine, Jiangxi Institute of Respiratory Diseases, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Yuanli Liu
- Department of Critical Care Medicine, The First Affiliated Hospital of Gannan Medical College, Ganzhou, Jiangxi, China
| | - Zhuozhuo Liu
- Department of Respiratory Medicine, Jiangxi Institute of Respiratory Diseases, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Lin Su
- Department of Geriatric Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Lili Yan
- Department of Respiratory Medicine, Jiangxi Institute of Respiratory Diseases, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
- Jiangxi Clinical Research Center for Respiratory Diseases, Nanchang, Jiangxi, China
- Jiangxi Hospital of China-Japan Friendship Hospital, Nanchang, Jiangxi, China
| | - Yuan Huang
- Department of Geriatric Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Ye Huang
- Department of Respiratory Medicine, Jiangxi Institute of Respiratory Diseases, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
- Jiangxi Clinical Research Center for Respiratory Diseases, Nanchang, Jiangxi, China
- Jiangxi Hospital of China-Japan Friendship Hospital, Nanchang, Jiangxi, China
| | - Wei Zhang
- Department of Respiratory Medicine, Jiangxi Institute of Respiratory Diseases, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
- Jiangxi Clinical Research Center for Respiratory Diseases, Nanchang, Jiangxi, China
| | - Xinping Xu
- Department of Respiratory Medicine, Jiangxi Institute of Respiratory Diseases, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
- Jiangxi Clinical Research Center for Respiratory Diseases, Nanchang, Jiangxi, China
- Jiangxi Hospital of China-Japan Friendship Hospital, Nanchang, Jiangxi, China
| | - Fanglin Zheng
- Department of Respiratory Medicine, Jiangxi Institute of Respiratory Diseases, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
- Jiangxi Clinical Research Center for Respiratory Diseases, Nanchang, Jiangxi, China
- Jiangxi Hospital of China-Japan Friendship Hospital, Nanchang, Jiangxi, China
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Maués DB, Maraschin JC, Duarte DÂ, Antoniêto ACC, Silva RN. Overexpression of the Transcription Factor Azf1 Reveals Novel Regulatory Functions and Impacts β-Glucosidase Production in Trichoderma reesei. J Fungi (Basel) 2023; 9:1173. [PMID: 38132774 PMCID: PMC10744372 DOI: 10.3390/jof9121173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/02/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023] Open
Abstract
The fungus Trichoderma reesei is an essential producer of enzymes that degrade lignocellulosic biomass to produce value-added bioproducts. The cellulolytic system of T. reesei is controlled by several transcription factors (TFs) that efficiently regulate the production of these enzymes. Recently, a new TF named Azf1 was identified as a positive regulator of cellulase expression. Here, we investigated novel regulatory functions of Azf1 by its overexpression. In the mutant strain OEazf1, overexpression of azf1 was achieved under both repression and induction conditions. Although azf1 was more abundant in transcript and protein, overexpression of this TF did not activate transcription of the cellulase gene in the presence of the repressor glucose, suggesting that Azf1 may be subject to posttranslational regulation. In cellulose, the expression of swo, encoding the accessory protein swollenin, and the β-glucosidases cel1a, cel1b, cel3b, and cel3g increases in the early stages of cultivation. The increased production of these β-glucosidases increases the hydrolysis rate of cellobiose and sophorose, which activates carbon catabolite repression (CCR) and causes repression of cellulase genes and the regulator Xyr1 in the later stages of cultivation. Moreover, overexpression of azf1 led to increased cellulase activity in T. reesei during long-term cultivation in cellulose and sugarcane bagasse. Our results provide new insights into the mechanisms regulating Azf1 and novel genes that are important targets of this TF. This work contributes to a better understanding of the complex mechanisms regulating cellulase expression in T. reesei. It will contribute to the development of strains with higher production of these essential enzymes.
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Affiliation(s)
| | | | | | | | - Roberto N. Silva
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14049-900, SP, Brazil; (D.B.M.); (J.C.M.); (D.Â.D.); (A.C.C.A.)
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6
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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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Lv D, Zhang W, Meng X, Liu W. Single Mutation in Transcriptional Activator Xyr1 Enhances Cellulase and Xylanase Production in Trichoderma reesei on Glucose. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:11993-12003. [PMID: 37523749 DOI: 10.1021/acs.jafc.3c03466] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
To achieve cost-effective production of lignocellulolytic enzymes for biorefinery processes, engineering transcription factors represents a powerful strategy to boost cellulase and xylanase in Trichoderma reesei. In this study, a novel mutation (R434L) in xylanase regulator 1 (Xyr1) was identified based on the yeast one-hybrid screening system. The point mutation was located in the middle homology region of Xyr1 with unclear functions, indicating a significant role for this domain in tuning Xyr1 transactivation. When constitutively expressed in T. reesei Δxyr1 (OEXR434L), Xyr1R434L led to highly improved production of both cellulases and xylanases on glucose compared with a strain similarly expressing Xyr1 (OEX). The respective 0.8- and 0.7-fold increases in extracellular pNPCase and xylanolytic activity were further verified to result from the greatly elevated transcription of major cellulase and xylanase genes in OEXR434L. Moreover, the saccharification efficiency of corn stover with OEXR434L enzyme cocktails was enhanced by 21% compared with that of OEX.
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Affiliation(s)
- Dongmei Lv
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
| | - Weixin Zhang
- 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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Ma C, Liu J, Tang J, Sun Y, Jiang X, Zhang T, Feng Y, Liu Q, Wang L. Current genetic strategies to investigate gene functions in Trichoderma reesei. Microb Cell Fact 2023; 22:97. [PMID: 37161391 PMCID: PMC10170752 DOI: 10.1186/s12934-023-02104-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 04/21/2023] [Indexed: 05/11/2023] Open
Abstract
The filamentous fungus Trichoderma reesei (teleomorph Hypocrea jecorina, Ascomycota) is a well-known lignocellulolytic enzymes-producing strain in industry. To increase the fermentation titer of lignocellulolytic enzymes, random mutagenesis and rational genetic engineering in T. reesei were carried out since it was initially found in the Solomon Islands during the Second World War. Especially the continuous exploration of the underlying regulatory network during (hemi)cellulase gene expression in the post-genome era provided various strategies to develop an efficient fungal cell factory for these enzymes' production. Meanwhile, T. reesei emerges competitiveness potential as a filamentous fungal chassis to produce proteins from other species (e.g., human albumin and interferon α-2b, SARS-CoV-2 N antigen) in virtue of the excellent expression and secretion system acquired during the studies about (hemi)cellulase production. However, all the achievements in high yield of (hemi)cellulases are impossible to finish without high-efficiency genetic strategies to analyze the proper functions of those genes involved in (hemi)cellulase gene expression or secretion. Here, we in detail summarize the current strategies employed to investigate gene functions in T. reesei. These strategies are supposed to be beneficial for extending the potential of T. reesei in prospective strain engineering.
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Affiliation(s)
- Chixiang Ma
- China Medical University-The Queen's University of Belfast Joint College, Shenyang, Liaoning, 110122, China
| | - Jialong Liu
- College of Basic Medical Sciences, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
| | - Jiaxin Tang
- College of Basic Medical Sciences, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
| | - Yuanlu Sun
- China Medical University-The Queen's University of Belfast Joint College, Shenyang, Liaoning, 110122, China
| | - Xiaojie Jiang
- China Medical University-The Queen's University of Belfast Joint College, Shenyang, Liaoning, 110122, China
| | - Tongtong Zhang
- China Medical University-The Queen's University of Belfast Joint College, Shenyang, Liaoning, 110122, China
| | - Yan Feng
- College of Life Sciences, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
| | - Qinghua Liu
- College of Basic Medical Sciences, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
| | - Lei Wang
- College of Basic Medical Sciences, Shanxi Medical University, Taiyuan, 030001, Shanxi, China.
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9
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Li N, Li J, Chen Y, Shen Y, Wei D, Wang W. Mechanism of Zn 2+ regulation of cellulase production in Trichoderma reesei Rut-C30. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:73. [PMID: 37118821 PMCID: PMC10148476 DOI: 10.1186/s13068-023-02323-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 04/18/2023] [Indexed: 04/30/2023]
Abstract
BACKGROUND Trichoderma reesei Rut-C30 is a hypercellulolytic mutant strain that degrades abundant sources of lignocellulosic plant biomass, yielding renewable biofuels. Although Zn2+ is an activator of enzymes in almost all organisms, its effects on cellulase activity in T. reesei have yet to be reported. RESULTS Although high concentrations of Zn2+ severely suppressed the extension of T. reesei mycelia, the application of 1-4 mM Zn2+ enhanced cellulase and xylanase production in the high-yielding cellulase-producing Rut-C30 strain of T. reesei. Expression of the major cellulase, xylanase, and two essential transcription activator genes (xyr1 and ace3) increased in response to Zn2+ stimulation. Transcriptome analysis revealed that the mRNA levels of plc-e encoding phospholipase C, which is involved in the calcium signaling pathway, were enhanced by Zn2+ application. The disruption of plc-e abolished the cellulase-positive influence of Zn2+ in the early phase of induction, indicating that plc-e is involved in Zn2+-induced cellulase production. Furthermore, treatment with LaCl3 (a plasma membrane Ca2+ channel blocker) and deletion of crz1 (calcineurin-responsive zinc finger transcription factor 1) indicated that calcium signaling is partially involved in this process. Moreover, we identified the zinc-responsive transcription factor zafA, the transcriptional levels of which declined in response to Zn2+ stress. Deletion of zafA indicates that this factor plays a prominent role in mediating the Zn2+-induced excessive production of cellulase. CONCLUSIONS For the first time, we have demonstrated that Zn2+ is toxic to T. reesei, although promotes a marked increase in cellulase production. This positive influence of Zn2+ is facilitated by the plc-e gene and zafA transcription factor. These findings provide insights into the role of Zn2+ in T. reesei and the mechanisms underlying signal transduction in cellulase synthesis.
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Affiliation(s)
- Ni Li
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P. O. Box 311, Shanghai, 200237, China
| | - Jing Li
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P. O. Box 311, Shanghai, 200237, China
| | - Yumeng Chen
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P. O. Box 311, Shanghai, 200237, China
| | - Yaling Shen
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P. O. Box 311, Shanghai, 200237, China
| | - Dongzhi Wei
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P. O. Box 311, Shanghai, 200237, China
| | - Wei Wang
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P. O. Box 311, Shanghai, 200237, China.
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10
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Ghosh S, Rusyn I, Dmytruk OV, Dmytruk KV, Onyeaka H, Gryzenhout M, Gafforov Y. Filamentous fungi for sustainable remediation of pharmaceutical compounds, heavy metal and oil hydrocarbons. Front Bioeng Biotechnol 2023; 11:1106973. [PMID: 36865030 PMCID: PMC9971017 DOI: 10.3389/fbioe.2023.1106973] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 01/31/2023] [Indexed: 02/16/2023] Open
Abstract
This review presents a comprehensive summary of the latest research in the field of bioremediation with filamentous fungi. The main focus is on the issue of recent progress in remediation of pharmaceutical compounds, heavy metal treatment and oil hydrocarbons mycoremediation that are usually insufficiently represented in other reviews. It encompasses a variety of cellular mechanisms involved in bioremediation used by filamentous fungi, including bio-adsorption, bio-surfactant production, bio-mineralization, bio-precipitation, as well as extracellular and intracellular enzymatic processes. Processes for wastewater treatment accomplished through physical, biological, and chemical processes are briefly described. The species diversity of filamentous fungi used in pollutant removal, including widely studied species of Aspergillus, Penicillium, Fusarium, Verticillium, Phanerochaete and other species of Basidiomycota and Zygomycota are summarized. The removal efficiency of filamentous fungi and time of elimination of a wide variety of pollutant compounds and their easy handling make them excellent tools for the bioremediation of emerging contaminants. Various types of beneficial byproducts made by filamentous fungi, such as raw material for feed and food production, chitosan, ethanol, lignocellulolytic enzymes, organic acids, as well as nanoparticles, are discussed. Finally, challenges faced, future prospects, and how innovative technologies can be used to further exploit and enhance the abilities of fungi in wastewater remediation, are mentioned.
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Affiliation(s)
- Soumya Ghosh
- Department of Genetics, Faculty of Natural and Agricultural Sciences, University of the Free State, Bloemfontein, South Africa,*Correspondence: Soumya Ghosh, ,
| | - Iryna Rusyn
- Department of Ecology and Sustainaible Environmental Management, Viacheslav Chornovil Institute of Sustainable Development, Lviv Polytechnic National University, Lviv, Ukraine
| | - Olena V. Dmytruk
- Institute of Cell Biology NAS of Ukraine, Lviv, Ukraine,Institute of Biology and Biotechnology, University of Rzeszow, Rzeszow, Poland
| | - Kostyantyn V. Dmytruk
- Institute of Cell Biology NAS of Ukraine, Lviv, Ukraine,Institute of Biology and Biotechnology, University of Rzeszow, Rzeszow, Poland
| | - Helen Onyeaka
- School of Chemical Engineering, University of Birmingham, Birmingham, United Kingdom
| | - Marieka Gryzenhout
- Department of Genetics, Faculty of Natural and Agricultural Sciences, University of the Free State, Bloemfontein, South Africa
| | - Yusufjon Gafforov
- Mycology Laboratory, Institute of Botany, Academy of Sciences of Republic of Uzbekistan, Tashkent, Uzbekistan,AKFA University, Tashkent, Uzbekistan
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11
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Role of the Nitrogen Metabolism Regulator TAM1 in Regulation of Cellulase Gene Expression in Trichoderma reesei. Appl Environ Microbiol 2023; 89:e0142122. [PMID: 36602369 PMCID: PMC9888229 DOI: 10.1128/aem.01421-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The filamentous fungus Trichoderma reesei is one of the most prolific cellulase producers and has been established as a model microorganism for investigating mechanisms modulating eukaryotic gene expression. Identification and functional characterization of transcriptional regulators involved in complex and stringent regulation of cellulase genes are, however, not yet complete. Here, a Zn(II)2Cys6-type transcriptional factor TAM1 that is homologous to Aspergillus nidulans TamA involved in nitrogen metabolism, was found not only to regulate ammonium utilization but also to control cellulase gene expression in T. reesei. Whereas Δtam1 cultivated with peptone as a nitrogen source did not exhibit a growth defect that was observed on ammonium, it was still significantly compromised in cellulase biosynthesis. The absence of TAM1 almost fully abrogated the rapid cellulase gene induction in a resting-cell-inducing system. Overexpression of gdh1 encoding the key ammonium assimilatory enzyme in Δtam1 rescued the growth defect on ammonium but not the defect in cellulase gene expression. Of note, mutation of the Zn(II)2Cys6 DNA-binding motif of TAM1 hardly affected cellulase gene expression, while a truncated ARE1 mutant lacking the C-terminal 12 amino acids that are required for the interaction with TAM1 interfered with cellulase biosynthesis. The defect in cellulase induction of Δtam1 was rescued by overexpression of the key transactivator for cellulase gene, XYR1. Our results thus identify a nitrogen metabolism regulator as a new modulator participating in the regulation of induced cellulase gene expression. IMPORTANCE Transcriptional regulators are able to integrate extracellular nutrient signals and exert a combinatorial control over various metabolic genes. A plethora of such factors therefore constitute a complex regulatory network ensuring rapid and accurate cellular response to acquire and utilize nutrients. Despite the in-depth mechanistic studies of functions of the Zn(II)2Cys6-type transcriptional regulator TamA and its orthologues in nitrogen utilization, their involvement in additional physiological processes remains unknown. In this study, we demonstrated that TAM1 exerts a dual regulatory role in mediating ammonium utilization and induced cellulase production in the well known cellulolytic fungus Trichoderma reesei, suggesting a potentially converged regulatory node between nitrogen utilization and cellulase biosynthesis. This study not only contributes to unveiling the intricate regulatory network underlying cellulase gene expression in cellulolytic fungus but also helps expand our knowledge of fungal strategies to achieve efficient and coordinated nutrient acquisition for rapid propagation.
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Shen L, Yan A, Wang Y, Wang Y, Liu H, Zhong Y. Tailoring the expression of Xyr1 leads to efficient production of lignocellulolytic enzymes in Trichoderma reesei for improved saccharification of corncob residues. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:142. [PMID: 36528622 PMCID: PMC9759857 DOI: 10.1186/s13068-022-02240-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022]
Abstract
BACKGROUND The filamentous fungus Trichoderma reesei is extensively used for the industrial-scale cellulase production. It has been well known that the transcription factor Xyr1 plays an important role in the regulatory network controlling cellulase gene expression. However, the role of Xyr1 in the regulation of cellulase expression has not been comprehensively elucidated, which hinders further improvement of lignocellulolytic enzyme production. RESULTS Here, the expression dosage of xyr1 was tailored in T. reesei by differentially overexpressing the xyr1 gene under the control of three strong promoters (Pegl2, Pcbh1, and Pcdna1), and the transcript abundance of xyr1 was elevated 5.8-, 12.6-, and 47.2-fold, respectively. We found expression of cellulase genes was significantly increased in the Pegl2-driven xyr1 overexpression strain QE2X, whereas relatively low in the Pcbh1- and Pcdna1-driven overexpression strains. We also found that the Pegl2-driven overexpression of xyr1 caused a more significant opening of chromatin in the core promoter region of the prominent cellulase genes. Furthermore, the cellulase activity showed a 3.2-fold increase in the strain QE2X, while insignificant improvement in the Pcbh1- and Pcdna1-driven strains. Finally, the saccharification efficiency toward acid-pretreated corncob residues containing high-content lignin by the crude enzyme from QE2X was increased by 57.2% compared to that from the parental strain. Moreover, LC-MS/MS and RT-qPCR analysis revealed that expression of accessory proteins (Cip1, Cip2, Swo1, and LPMOs) was greatly improved in QE2X, which partly explained the promoting effect of the Pegl2-driven overexpression on enzymatic hydrolysis of lignocellulose biomass. CONCLUSIONS Our results underpin that the precise tailoring expression of xyr1 is essential for highly efficient cellulase synthesis, which provide new insights into the role of Xyr1 in regulating cellulase expression in T. reesei. Moreover, these results also provides a prospective strategy for strain improvement to enhance the lignocellulolytic enzyme production for use in biorefinery applications.
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Affiliation(s)
- Linjing Shen
- grid.27255.370000 0004 1761 1174State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237 People’s Republic of China
| | - Aiqin Yan
- grid.27255.370000 0004 1761 1174State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237 People’s Republic of China
| | - Yifan Wang
- grid.27255.370000 0004 1761 1174State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237 People’s Republic of China
| | - Yubo Wang
- grid.27255.370000 0004 1761 1174State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237 People’s Republic of China
| | - Hong Liu
- grid.27255.370000 0004 1761 1174State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237 People’s Republic of China
| | - Yaohua Zhong
- grid.27255.370000 0004 1761 1174State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237 People’s Republic of China
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13
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Sun X, Liang Y, Wang Y, Zhang H, Zhao T, Yao B, Luo H, Huang H, Su X. Simultaneous manipulation of multiple genes within a same regulatory stage for iterative evolution of Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:26. [PMID: 35248141 PMCID: PMC8898424 DOI: 10.1186/s13068-022-02122-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 02/19/2022] [Indexed: 11/12/2022]
Abstract
Background While there is growing interest in developing non-canonical filamentous fungi as hosts for producing secretory proteins, genetic engineering of filamentous fungi for improved expression often relies heavily on the understanding of regulatory mechanisms. Results In this study, using the cellulase-producing filamentous fungus Trichoderma reesei as a model system, we designed a semi-rational strategy by arbitrarily dividing the regulation of cellulase production into three main stages-transcription, secretion, and cell metabolism. Selected regulatory or functional genes that had been experimentally verified or predicted to enhance cellulase production were overexpressed using strong inducible or constitutive promoters, while those that would inhibit cellulase production were repressed via RNAi-mediated gene silencing. A T. reesei strain expressing the surface-displayed DsRed fluorescent protein was used as the recipient strain. After three consecutive rounds of engineering, the cellulase activity increased to up to 4.35-fold and the protein concentration increased to up to 2.97-fold in the genetically modified strain. Conclusions We demonstrated that, as a proof-of-concept, selected regulatory or functional genes within an arbitrarily defined stage could be pooled to stimulate secretory cellulase production, and moreover, this method could be iteratively used for further improvement. This method is semi-rational and can essentially be used in filamentous fungi with little regulatory information. Supplementary Information The online version contains supplementary material available at 10.1186/s13068-022-02122-0.
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Arai T, Ichinose S, Shibata N, Kakeshita H, Kodama H, Igarashi K, Takimura Y. Inducer-free cellulase production system based on the constitutive expression of mutated XYR1 and ACE3 in the industrial fungus Trichoderma reesei. Sci Rep 2022; 12:19445. [PMID: 36376415 PMCID: PMC9663580 DOI: 10.1038/s41598-022-23815-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 11/07/2022] [Indexed: 11/16/2022] Open
Abstract
Trichoderma reesei is a widely used host for producing cellulase and hemicellulase cocktails for lignocellulosic biomass degradation. Here, we report a genetic modification strategy for industrial T. reesei that enables enzyme production using simple glucose without inducers, such as cellulose, lactose and sophorose. Previously, the mutated XYR1V821F or XYR1A824V was known to induce xylanase and cellulase using only glucose as a carbon source, but its enzyme composition was biased toward xylanases, and its performance was insufficient to degrade lignocellulose efficiently. Therefore, we examined combinations of mutated XYR1V821F and constitutively expressed CRT1, BGLR, VIB1, ACE2, or ACE3, known as cellulase regulators and essential factors for cellulase expression to the T. reesei E1AB1 strain that has been highly mutagenized for improving enzyme productivity and expressing a ß-glucosidase for high enzyme performance. The results showed that expression of ACE3 to the mutated XYR1V821F expressing strain promoted cellulase expression. Furthermore, co-expression of these two transcription factors also resulted in increased productivity, with enzyme productivity 1.5-fold higher than with the conventional single expression of mutated XYR1V821F. Additionally, that productivity was 5.5-fold higher compared to productivity with an enhanced single expression of ACE3. Moreover, although the DNA-binding domain of ACE3 had been considered essential for inducer-free cellulase production, we found that ACE3 with a partially truncated DNA-binding domain was more effective in cellulase production when co-expressed with a mutated XYR1V821F. This study demonstrates that co-expression of the two transcription factors, the mutated XYR1V821F or XYR1A824V and ACE3, resulted in optimized enzyme composition and increased productivity.
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Affiliation(s)
- Toshiharu Arai
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640‑8580, Japan
| | - Sakurako Ichinose
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640‑8580, Japan
| | - Nozomu Shibata
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640‑8580, Japan
| | - Hiroshi Kakeshita
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640‑8580, Japan.
| | - Hiroshi Kodama
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640‑8580, Japan
| | - Kazuaki Igarashi
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640‑8580, Japan
| | - Yasushi Takimura
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640‑8580, Japan
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MtTRC-1, a Novel Transcription Factor, Regulates Cellulase Production via Directly Modulating the Genes Expression of the Mthac-1 and Mtcbh-1 in Myceliophthora thermophila. Appl Environ Microbiol 2022; 88:e0126322. [PMID: 36165620 PMCID: PMC9552611 DOI: 10.1128/aem.01263-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
The thermophilic fungus Myceliophthora thermophila has been used to produce industrial enzymes and biobased chemicals. In saprotrophic fungi, the mechanisms regulating cellulase production have been studied, which revealed the involvement of multiple transcription factors. However, in M. thermophila, the transcription factors influencing cellulase gene expression and secretion remain largely unknown. In this study, we identified and characterized a novel cellulase regulator (MtTRC-1) in M. thermophila through a combination of functional genomics and genetic analyses. Deletion of Mttrc-1 resulted in significantly decreased cellulase production and activities. Transcriptome analysis revealed downregulation of not only the encoding genes of main cellulases but also the transcriptional regulator MtHAC-1 of UPR pathway after disruption of MtTRC-1 under cellulolytic induction conditions. Herein, we also characterized the ortholog of the yeast HAC1p in M. thermophila. We show that Mthac-1 mRNA undergoes an endoplasmic reticulum (ER) stress-induced splicing by removing a 23-nucleotide (nt) intron. Notably, the protein secretion on cellulose was dramatically impaired by the deletion of MtHAC-1. Moreover, the colonial growth on various carbon sources was defective in the absence of MtHAC-1. Electrophoretic mobility shift assays and chromatin immunoprecipitation assays verified MtTRC-1 regulates the transcription of Mthac-1 and the major cellulase gene Mtcbh-1 by binding directly to the promoters in vitro and in vivo. Furthermore, DNase I footprinting assays identified the putative consensus binding site (5′-GNG/C-3′). These results revealed the importance of MtTRC-1 for positively regulating cellulase production. This finding has clarified the complex regulatory pathways involved in cellulolytic enzyme production. IMPORTANCE In the present study, we characterized a novel regulator MtTRC-1 in M. thermophila, which regulated cellulase production through direct transcriptional regulation of the Mthac-1 and Mtcbh-1 genes. Our data demonstrated that MtHAC-1 is a key factor for the cellulase secretion capacity of M. thermophila. Our data indicate that this thermophilic fungus regulates cellulase production through a multilevels network, in which the protein secretory pathway is modulated by MtHAC-1-dependent UPR pathway and the cellulase gene expression is directly regulated in parallel by transcription factors. The conservation of Mttrc1 in filamentous fungi suggests this mechanism may be exploited to engineer filamentous fungal cell factories capable of producing proteins on an industrial scale.
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Liu P, Chang H, Xu Q, Wang D, Tang Y, Hu X, Lin M, Liu Z. Peptide Aptamer PA3 Attenuates the Viability of Aeromonas veronii by Hindering of Small Protein B-Outer Membrane Protein A Signal Pathway. Front Microbiol 2022; 13:900234. [PMID: 35663889 PMCID: PMC9159911 DOI: 10.3389/fmicb.2022.900234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 04/12/2022] [Indexed: 11/15/2022] Open
Abstract
The small protein B (SmpB), previously acting as a ribosome rescue factor for translation quality control, is required for cell viability in bacteria. Here, our study reveals that SmpB possesses new function which regulates the expression of outer membrane protein A (ompA) gene as a transcription factor in Aeromonas veronii. The deletion of SmpB caused the lower transcription expression of ompA by Quantitative Real-Time PCR (qPCR). Electrophoretic mobility shift assay (EMSA) and DNase I Footprinting verified that the SmpB bound at the regions of −46 to −28 bp, −18 to +4 bp, +21 to +31 bp, and +48 to +59 bp of the predicted ompA promoter (PompA). The key sites C52AT was further identified to interact with SmpB when PompA was fused with enhanced green fluorescent protein (EGFP) and co-transformed with SmpB expression vector for the fluorescence detection, and the result was further confirmed in microscale thermophoresis (MST) assays. Besides, the amino acid sites G11S, F26I, and K152 in SmpB were the key sites for binding to PompA. In order to further develop peptide antimicrobial agents, the peptide aptamer PA3 was screened from the peptide aptamer (PA) library by bacterial two-hybrid method. The drug sensitivity test showed that PA3 effectively inhibited the growth of A. veronii. In summary, these results demonstrated that OmpA was a good drug target for A. veronii, which was regulated by the SmpB protein and the selected peptide aptamer PA3 interacted with OmpA protein to disable SmpB-OmpA signal pathway and inhibited A. veronii, suggesting that it could be used as an antimicrobial agent for the prevention and treatment of pathogens.
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Affiliation(s)
- Peng Liu
- School of Life Sciences, Hainan University, Haikou, China
- Center for Medical Innovation, School of Basic Medical Science, Guangxi University of Chinese Medicine, Nanning, China
| | - Huimin Chang
- School of Life Sciences, Hainan University, Haikou, China
| | - Qi Xu
- School of Life Sciences, Hainan University, Haikou, China
| | - Dan Wang
- School of Life Sciences, Hainan University, Haikou, China
| | - Yanqiong Tang
- School of Life Sciences, Hainan University, Haikou, China
- One Health Institute, Hainan University, Haikou, China
| | - Xinwen Hu
- School of Life Sciences, Hainan University, Haikou, China
| | - Min Lin
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhu Liu
- School of Life Sciences, Hainan University, Haikou, China
- One Health Institute, Hainan University, Haikou, China
- *Correspondence: Zhu Liu,
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Beier S, Stiegler M, Hitzenhammer E, Monika S. Screening for genes involved in cellulase regulation by expression under the control of a novel constitutive promoter in Trichoderma reesei. CURRENT RESEARCH IN BIOTECHNOLOGY 2022. [DOI: 10.1016/j.crbiot.2022.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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18
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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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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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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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21
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Fan C, Zhang W, Su X, Ji W, Luo H, Zhang Y, Liu B, Yao B, Huang H, Xu X. CRISPR/Cas9-mediated genome editing directed by a 5S rRNA-tRNA Gly hybrid promoter in the thermophilic filamentous fungus Humicola insolens. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:206. [PMID: 34688310 PMCID: PMC8542335 DOI: 10.1186/s13068-021-02057-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Humicola insolens is a filamentous fungus with high potential of producing neutral and heat- and alkali-resistant cellulase. However, the genetic engineering tools, particularly the genome-editing tool, are scarce, hindering the study of cellulase expression regulation in this organism. RESULTS Herein, a CRISPR/Cas9 genome-editing system was established in H. insolens based on a hybrid 5S rRNA-tRNAGly promoter. This system is superior to the HDV (hepatitis delta virus) system in genome editing, allowing highly efficient single gene destruction in H. insolens with rates of deletion up to 84.1% (37/44). With this system, a putative pigment synthesis gene pks and the transcription factor xyr1 gene were disrupted with high efficiency. Moreover, the extracellular protein concentration and cellulase activity largely decreased when xyr1 was deleted, demonstrating for the first time that Xyr1 plays an important role in cellulase expression regulation. CONCLUSIONS The established CRISPR/Cas9 system is a powerful genetic operation tool for H. insolens, which will accelerate studies on the regulation mechanism of cellulase expression and engineering of H. insolens for higher cellulase production.
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Affiliation(s)
- Chao Fan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Wei Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Xiaoyun Su
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China
| | - Wangli Ji
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Huiying Luo
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China
| | - Yuhong Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Bo Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Bin Yao
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China
| | - Huoqing Huang
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China.
| | - Xinxin Xu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China.
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22
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Yan S, Xu Y, Yu XW. From induction to secretion: a complicated route for cellulase production in Trichoderma reesei. BIORESOUR BIOPROCESS 2021; 8:107. [PMID: 38650205 PMCID: PMC10991602 DOI: 10.1186/s40643-021-00461-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 10/16/2021] [Indexed: 11/10/2022] Open
Abstract
The filamentous fungus Trichoderma reesei has been widely used for cellulase production that has extensive applications in green and sustainable development. Increasing costs and depletion of fossil fuels provoke the demand for hyper-cellulase production in this cellulolytic fungus. To better manipulate T. reesei for enhanced cellulase production and to lower the cost for large-scale fermentation, it is wise to have a comprehensive understanding of the crucial factors and complicated biological network of cellulase production that could provide new perspectives for further exploration and modification. In this review, we summarize recent progress and give an overview of the cellular process of cellulase production in T. reesei, including the carbon source-dependent cellulase induction, complicated transcriptional regulation network, and efficient protein assembly and trafficking. Among that, the key factors involved in cellulase production were emphasized, shedding light on potential perspectives for further engineering.
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Affiliation(s)
- Su Yan
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China
| | - Yan Xu
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China
| | - Xiao-Wei Yu
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China.
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China.
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23
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Chen Y, Wang W, Liu P, Lin A, Fan X, Wu C, Li N, Wei L, Wei D. The novel repressor Rce2 competes with Ace3 to regulate cellulase gene expression in the filamentous fungus Trichoderma reesei. Mol Microbiol 2021; 116:1298-1314. [PMID: 34608686 DOI: 10.1111/mmi.14825] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/22/2021] [Accepted: 09/27/2021] [Indexed: 11/29/2022]
Abstract
The filamentous fungus Trichoderma reesei is widely used for industrial cellulase production. In T. reesei, cellulase gene expression is tightly controlled by a regulatory network involving multiple transcription factors. Here, we isolated a novel protein, Rce2, using a pull-down assay and mass spectrometry analysis, from a partial carbon catabolite de-repression mutant, T. reesei Rut-C30, cultured under glucose-repressing conditions. Deletion and overexpression of Rce2 in T. reesei wild-type QM6a and mutant Rut-C30 revealed that Rce2 acts as a repressor of cellulase gene expression. DNase I footprinting assays, electrophoretic mobility shift assays, and chromatin immunoprecipitation assays revealed that Rce2 was located in the nucleus and bound to the consensus sequences 5'-(T/A)NNNNCCG-3' and 5'-CGGNNNN(T/A)-3' in the promoters of cellulase-related genes to repress their transcription. Additionally, Rce2 antagonized Ace3 binding to the cbh1 promoter to repress its transcription. However, Rce2 was not involved in Cre1-mediated carbon catabolite repression. These results demonstrate the mechanism through which Rce2 represses the expression of cellulase genes and provide novel insights into the regulatory system of cellulases and methods that can be used for the regulation of gene expression in T. reesei.
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Affiliation(s)
- Yumeng Chen
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Wei Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Pei Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Aibo Lin
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Xingjia Fan
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Chuan Wu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Ni Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Liujing Wei
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Dongzhi Wei
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
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24
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Mondal S, Halder SK, Mondal KC. Tailoring in fungi for next generation cellulase production with special reference to CRISPR/CAS system. SYSTEMS MICROBIOLOGY AND BIOMANUFACTURING 2021; 2:113-129. [PMID: 38624901 PMCID: PMC8319711 DOI: 10.1007/s43393-021-00045-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 12/14/2022]
Abstract
Cellulose is the utmost plenteous source of biopolymer in our earth, and fungi are the most efficient and ubiquitous organism in degrading the cellulosic biomass by synthesizing cellulases. Tailoring through genetic manipulation has played a substantial role in constructing novel fungal strains towards improved cellulase production of desired traits. However, the traditional methods of genetic manipulation of fungi are time-consuming and tedious. With the availability of the full-genome sequences of several industrially relevant filamentous fungi, CRISPR-CAS (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein) technology has come into the focus for the proficient development of manipulated strains of filamentous fungi. This review summarizes the mode of action of cellulases, transcription level regulation for cellulase expression, various traditional strategies of genetic manipulation with CRISPR-CAS technology to develop modified fungal strains for a preferred level of cellulase production, and the futuristic trend in this arena of research.
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Affiliation(s)
- Subhadeep Mondal
- Center for Life Sciences, Vidyasagar University, Midnapore, 721102 West Bengal India
| | - Suman Kumar Halder
- Department of Microbiology, Vidyasagar University, Midnapore, 721102 West Bengal India
| | - Keshab Chandra Mondal
- Department of Microbiology, Vidyasagar University, Midnapore, 721102 West Bengal India
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25
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Chen X, Song B, Liu M, Qin L, Dong Z. Understanding the Role of Trichoderma reesei Vib1 in Gene Expression during Cellulose Degradation. J Fungi (Basel) 2021; 7:jof7080613. [PMID: 34436152 PMCID: PMC8397228 DOI: 10.3390/jof7080613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/26/2021] [Accepted: 07/26/2021] [Indexed: 11/17/2022] Open
Abstract
Vib1, a member of the Ndt80/PhoG-like transcription factor family, has been shown to be essential for cellulase production of Trichoderma reesei. Here, we combined transcriptomic and genetic analyses to gain mechanistic insights into the roles of Vib1 during cellulose degradation. Our transcriptome analysis showed that the vib1 deletion caused 586 genes with decreased expression and 431 genes with increased expression on cellulose. The downregulated genes were enriched for Gene Ontology terms associated with carbohydrate metabolism, transmembrane transport, oxidoreductase activity, and transcription factor activity. Of the 258 genes induced by cellulose, 229 showed no or decreased expression in Δvib1 on cellulose, including almost all (hemi)cellulase genes, crucial sugar transporter genes (IDs:69957, 3405), and the genes encoding main transcriptional activators Xyr1 and Ace3. Additionally, Vib1 also regulated the expression of genes involved in secondary metabolism. Further comparison of the transcriptomes of Δvib1 and Δxyr1 in cellulose revealed that the genes regulated by Vib1 had much overlap with Xyr1 targets especially for the gene set induced by cellulose, presumably whose expression requires the cooperativity between Vib1 and Xyr1. Genetic evidence indicated that Vib1 regulates cellulase gene expression partially via Xyr1. Our results will provide new clues for strain improvement.
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Affiliation(s)
- Xiuzhen Chen
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (X.C.); (B.S.); (M.L.)
| | - Bingran Song
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (X.C.); (B.S.); (M.L.)
| | - Minglu Liu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (X.C.); (B.S.); (M.L.)
| | - Lina Qin
- National and Local Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou 350117, China;
| | - Zhiyang Dong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (X.C.); (B.S.); (M.L.)
- Correspondence:
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26
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Trichoderma reesei ACE4, a Novel Transcriptional Activator Involved in the Regulation of Cellulase Genes during Growth on Cellulose. Appl Environ Microbiol 2021; 87:e0059321. [PMID: 34047636 DOI: 10.1128/aem.00593-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The filamentous fungus Trichoderma reesei is a model strain for cellulase production. Cellulase gene expression in T. reesei is controlled by multiple transcription factors. Here, we identified by comparative genomic screening a novel transcriptional activator, ACE4 (activator of cellulase expression 4), that positively regulates cellulase gene expression on cellulose in T. reesei. Disruption of the ace4 gene significantly decreased expression of four main cellulase genes and the essential cellulase transcription factor-encoding gene ace3. Overexpression of ace4 increased cellulase production by approximately 22% compared to that in the parental strain. Further investigations using electrophoretic mobility shift assays, DNase I footprinting assays, and chromatin immunoprecipitation assays indicated that ACE4 directly binds to the promoter of cellulase genes by recognizing the two adjacent 5'-GGCC-3' sequences. Additionally, ACE4 directly binds to the promoter of ace3 and, in turn, regulates the expression of ACE3 to facilitate cellulase production. Collectively, these results demonstrate an important role for ACE4 in regulating cellulase gene expression, which will contribute to understanding the mechanism underlying cellulase expression in T. reesei. IMPORTANCE T. reesei is commonly utilized in industry to produce cellulases, enzymes that degrade lignocellulosic biomass for the production of bioethanol and bio-based products. T. reesei is capable of rapidly initiating the biosynthesis of cellulases in the presence of cellulose, which has made it useful as a model fungus for studying gene expression in eukaryotes. Cellulase gene expression is controlled through multiple transcription factors at the transcriptional level. However, the molecular mechanisms by which transcription is controlled remain unclear. In the present study, we identified a novel transcription factor, ACE4, which regulates cellulase expression on cellulose by binding to the promoters of cellulase genes and the cellulase activator gene ace3. Our study not only expands the general functional understanding of the novel transcription factor ACE4 but also provides evidence for the regulatory mechanism mediating gene expression in T. reesei.
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27
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28
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Sukumaran RK, Christopher M, Kooloth-Valappil P, Sreeja-Raju A, Mathew RM, Sankar M, Puthiyamadam A, Adarsh VP, Aswathi A, Rebinro V, Abraham A, Pandey A. Addressing challenges in production of cellulases for biomass hydrolysis: Targeted interventions into the genetics of cellulase producing fungi. BIORESOURCE TECHNOLOGY 2021; 329:124746. [PMID: 33610429 DOI: 10.1016/j.biortech.2021.124746] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 01/12/2021] [Accepted: 01/15/2021] [Indexed: 06/12/2023]
Abstract
Lignocellulosic materials are the favoured feedstock for biorefineries due to their abundant availability and non-completion with food. Biobased technologies for refining these materials are limited mainly by the cost of biomass hydrolyzing enzymes, typically sourced from filamentous fungi. Therefore, considerable efforts have been directed at improving the quantity and quality of secreted lignocellulose degrading enzymes from fungi in order to attain overall economic viability. Process improvements and media engineering probably have reached their thresholds and further production enhancements require modifying the fungal metabolism to improve production and secretion of these enzymes. This review focusses on the types and mechanisms of action of known fungal biomass degrading enzymes, our current understanding of the genetic control exerted on their expression, and possible routes for intervention, especially on modulating catabolite repression, transcriptional regulators, signal transduction, secretion pathways etc., in order to improve enzyme productivity, activity and stability.
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Affiliation(s)
- Rajeev K Sukumaran
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India.
| | - Meera Christopher
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Prajeesh Kooloth-Valappil
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - AthiraRaj Sreeja-Raju
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Reshma M Mathew
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Meena Sankar
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Anoop Puthiyamadam
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India
| | - Velayudhanpillai-Prasannakumari Adarsh
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India
| | - Aswathi Aswathi
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Valan Rebinro
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India
| | - Amith Abraham
- Department of Chemical Engineering, Hanyang University, Seoul, Republic of Korea
| | - Ashok Pandey
- Centre for Innovation and Translational Research, CSIR-Indian Institute of Toxicology Research, Lucknow, India
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29
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Abstract
Trichoderma reesei has 11 putative β-glucosidases in its genome, playing key parts in the induction and production of cellulase. Nevertheless, the reason why the T. reesei genome encodes so many β-glucosidases and the distinct role each β-glucosidase plays in cellulase production remain unknown. In the present study, the cellular function and distribution of 10 known β-glucosidases (CEL3B, CEL3E, CEL3F, CEL3H, CEL3J, CEL1A, CEL3C, CEL1B, CEL3G, and CEL3D) were explored in T. reesei, leaving out BGL1 (CEL3A), which has been well investigated. We found that the overexpression of cel3b or cel3g significantly enhanced extracellular β-glucosidase production, whereas the overexpression of cel1b severely inhibited cellulase production by cellulose, resulting in nearly no growth of T. reesei. Four types of cellular distribution patterns were observed for β-glucosidases in T. reesei: (i) CEL3B, CEL3E, CEL3F, and CEL3G forming clearly separated protein secretion vesicles in the cytoplasm; (ii) CEL3H and CEL3J diffusing the whole endomembrane as well as the cell membrane with protein aggregation, like a reticular network; (iii) CEL1A and CEL3D in vacuoles; (iv) and CEL3C in the nucleus. β-glucosidases CEL1A, CEL3B, CEL3E, CEL3F, CEL3G, CEL3H, and CEL3J were identified as extracellular, CEL3C and CEL3D as intracellular, and CEL1B as unknown. The extracellular β-glucosidases CEL3B, CEL3E, CEL3F, CEL3H, and CEL3G were secreted through a tip-directed conventional secretion pathway, and CEL1A, via a vacuole-mediated pathway that was achieved without any signal peptide, while CEL3J was secreted via an unconventional protein pathway bypassing the endoplasmic reticulum (ER) and Golgi.
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30
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Zhao Q, Liu Q, Wang Q, Qin Y, Zhong Y, Gao L, Liu G, Qu Y. Disruption of the Trichoderma reesei gul1 gene stimulates hyphal branching and reduces broth viscosity in cellulase production. J Ind Microbiol Biotechnol 2021; 48:6132311. [PMID: 33693788 PMCID: PMC9113457 DOI: 10.1093/jimb/kuab012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 02/05/2021] [Indexed: 12/03/2022]
Abstract
Hyphal morphology is considered to have a close relationship with the production
level of secreted proteins by filamentous fungi. In this study, the
gul1 gene, which encodes a putative mRNA-binding protein,
was disrupted in cellulase-producing fungus Trichoderma reesei.
The hyphae of Δgul1 strain produced more lateral
branches than the parent strain. Under the condition for cellulase production,
disruption of gul1 resulted in smaller mycelial clumps and
significantly lower viscosity of fermentation broth. In addition, cellulase
production was improved by 22% relative to the parent strain.
Transcriptome analysis revealed that a set of genes encoding cell wall
remodeling enzymes as well as hydrophobins were differentially expressed in the
Δgul1 strain. The results suggest that the
regulatory role of gul1 in cell morphogenesis is likely
conserved in filamentous fungi. To our knowledge, this is the first report on
the engineering of gul1 in an industrially important
fungus.
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Affiliation(s)
- Qinqin Zhao
- State Key Laboratory of Microbial Technology, Shandong University, 72 Binhai Road, 266237 Qingdao, China
| | - Qin Liu
- State Key Laboratory of Microbial Technology, Shandong University, 72 Binhai Road, 266237 Qingdao, China
| | - Qi Wang
- National Glycoengineering Research Center, Shandong University, 27 Binhai Road, 266237 Qingdao, China
| | - Yuqi Qin
- National Glycoengineering Research Center, Shandong University, 27 Binhai Road, 266237 Qingdao, China
| | - Yaohua Zhong
- State Key Laboratory of Microbial Technology, Shandong University, 72 Binhai Road, 266237 Qingdao, China
| | - Liwei Gao
- State Key Laboratory of Microbial Technology, Shandong University, 72 Binhai Road, 266237 Qingdao, China.,Tobacco Research Institute of Chinese Academy of Agricultural Sciences, 11 Keyuanjingsi Road, 266101 Qingdao, China
| | - Guodong Liu
- State Key Laboratory of Microbial Technology, Shandong University, 72 Binhai Road, 266237 Qingdao, China.,National Glycoengineering Research Center, Shandong University, 27 Binhai Road, 266237 Qingdao, China
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, Shandong University, 72 Binhai Road, 266237 Qingdao, China.,National Glycoengineering Research Center, Shandong University, 27 Binhai Road, 266237 Qingdao, China
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31
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Karuppiah V, Zhixiang L, Liu H, Vallikkannu M, Chen J. Co-culture of Vel1-overexpressed Trichoderma asperellum and Bacillus amyloliquefaciens: An eco-friendly strategy to hydrolyze the lignocellulose biomass in soil to enrich the soil fertility, plant growth and disease resistance. Microb Cell Fact 2021; 20:57. [PMID: 33653343 PMCID: PMC7927390 DOI: 10.1186/s12934-021-01540-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 02/10/2021] [Indexed: 11/17/2022] Open
Abstract
Background Retention of agricultural bio-mass residues without proper treatment could affect the subsequent plant growth. In the present investigation, the co-cultivation of genetically engineered T. asperellum and B. amyloliquefaciens has been employed for multiple benefits including the enrichment of lignocellulose biodegradation, plant growth, defense potential and disease resistance. Results The Vel1 gene predominantly regulates the secondary metabolites, sexual and asexual development as well as cellulases and polysaccharide hydrolases productions. Overexpression mutant of the Trichoderma asperellum Vel1 locus (TA OE-Vel1) enhanced the activity of FPAase, CMCase, PNPCase, PNPGase, xylanase I, and xylanase II through the regulation of transcription regulating factors and the activation of cellulase and xylanase encoding genes. Further, these genes were induced upon co-cultivation with Bacillus amyloliquefaciens (BA). The co-culture of TA OE-Vel1 + BA produced the best composition of enzymes and the highest biomass hydrolysis yield of 89.56 ± 0.61%. The co-culture of TA OE-Vel1 + BA increased the corn stover degradation by the secretion of cellulolytic enzymes and maintained the C/N ratio of the corn stover amended soil. Moreover, the TA OE-Vel1 + BA increased the maize plant growth, expression of defense gene and disease resistance against Fusarium verticillioides and Cohilohorus herostrophus. Conclusion The co-cultivation of genetically engineered T. asperellum and B. amyloliquefaciens could be utilized as a profound and meaningful technique for the retention of agro residues and subsequent plant growth.
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Affiliation(s)
- Valliappan Karuppiah
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800, Dongchuan Road, Minhang, Shanghai, 200240, PR China.,The State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, PR China
| | - Lu Zhixiang
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800, Dongchuan Road, Minhang, Shanghai, 200240, PR China.,The State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, PR China
| | - Hongyi Liu
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800, Dongchuan Road, Minhang, Shanghai, 200240, PR China.,The State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, PR China
| | - Murugappan Vallikkannu
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800, Dongchuan Road, Minhang, Shanghai, 200240, PR China.,The State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, PR China
| | - Jie Chen
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800, Dongchuan Road, Minhang, Shanghai, 200240, PR China. .,The State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, PR China.
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Dual Regulatory Role of Chromatin Remodeler ISW1 in Coordinating Cellulase and Secondary Metabolite Biosynthesis in Trichoderma reesei. mBio 2021; 13:e0345621. [PMID: 35130719 PMCID: PMC8822348 DOI: 10.1128/mbio.03456-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The saprophytic filamentous fungus Trichoderma reesei represents one of the most prolific cellulase producers isolated from nature. T. reesei also produces a typical yellow pigment identified as sorbicillinoids during cultivation. Here, we identified an evolutionarily conserved histone remodeling factor, ISW1, in T. reesei that simultaneously participates in regulating cellulase and the yellow pigment biosynthesis. Trisw1 deletion almost abolished vegetable growth, asexual spore formation, and cellulase gene expression. However, its absence significantly enhanced the production of the yellow pigment. The observed dual regulatory role of TrISW1 was dependent on its ATPase activity. We demonstrated that Trisw1 disruption elevated the transcription of ypr1 coding for the transcriptional activator of sor genes encoding the polyketide synthases catalyzing the biosynthesis of sorbicillinoids but compromised that of xyr1 encoding the key transcriptional activator of cellulase genes. Discrete T. reesei homologous ISW1 accessory factors were also found to exert differential effects on the expression of these two types of genes. Further analyses showed that TrISW1 was recruited to cellulase gene promoters, and its absence interfered with loss of histone H4 at the cbh1 and eg1 promoters upon cellulose induction. To the contrary, Trisw1 deletion facilitated loss of H4 at the sor locus. These data indicate that TrISW1 represents an important chromatin remodeler with a dual role in coordinating the cellulolytic response and biosynthesis of the major secondary metabolite in T. reesei. IMPORTANCE Microorganisms, including Trichoderma reesei, constantly face the challenge to outcompete other species to ensure efficient colonization in their natural habitat. They achieve this usually by adopting two alternative strategies by either maintaining fast growth on limited nutrient resources or producing a versatile array of secondary metabolites to fight against competitors. These two strategies, however, have to be subtly controlled to balance the assignment of and thus make the best use of cellular resources. Here, we identified a chromatin remodeling factor, TrISW1, with a dual role in coordinating the cellulolytic response and biosynthesis of the major secondary metabolite in T. reesei. The data also provide a novel insight into how T. reesei takes advantage of a chromatin remodeler to exquisitely balance two different adaptive strategies to ensure an efficient allocation of cellular resources to achieve efficient colonization in a specific environment.
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Wang L, Zhang W, Cao Y, Zheng F, Zhao G, Lv X, Meng X, Liu W. Interdependent recruitment of CYC8/TUP1 and the transcriptional activator XYR1 at target promoters is required for induced cellulase gene expression in Trichoderma reesei. PLoS Genet 2021; 17:e1009351. [PMID: 33606681 PMCID: PMC7894907 DOI: 10.1371/journal.pgen.1009351] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 01/12/2021] [Indexed: 11/19/2022] Open
Abstract
Cellulase production in filamentous fungus Trichoderma reesei is highly responsive to various environmental cues involving multiple positive and negative regulators. XYR1 (Xylanase regulator 1) has been identified as the key transcriptional activator of cellulase gene expression in T. reesei. However, the precise mechanism by which XYR1 achieves transcriptional activation of cellulase genes is still not fully understood. Here, we identified the TrCYC8/TUP1 complex as a novel coactivator for XYR1 in T. reesei. CYC8/TUP1 is the first identified transcriptional corepressor complex mediating repression of diverse genes in Saccharomyces cerevisiae. Knockdown of Trcyc8 or Trtup1 resulted in markedly impaired cellulase gene expression in T. reesei. We found that TrCYC8/TUP1 was recruited to cellulase gene promoters upon cellulose induction and this recruitment is dependent on XYR1. We further observed that repressed Trtup1 or Trcyc8 expression caused a strong defect in XYR1 occupancy and loss of histone H4 at cellulase gene promoters. The defects in XYR1 binding and transcriptional activation of target genes in Trtup1 or Trcyc8 repressed cells could not be overcome by XYR1 overexpression. Our results reveal a novel coactivator function for TrCYC8/TUP1 at the level of activator binding, and suggest a mechanism in which interdependent recruitment of XYR1 and TrCYC8/TUP1 to cellulase gene promoters represents an important regulatory circuit in ensuring the induced cellulase gene expression. These findings thus contribute to unveiling the intricate regulatory mechanism underlying XYR1-mediated cellulase gene activation and also provide an important clue that will help further improve cellulase production by T. reesei.
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Affiliation(s)
- Lei Wang
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, Shandong, People’s Republic of China
| | - Weixin Zhang
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, Shandong, People’s Republic of China
| | - Yanli Cao
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, Shandong, People’s Republic of China
| | - Fanglin Zheng
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, Shandong, People’s Republic of China
| | - Guolei Zhao
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, Shandong, People’s Republic of China
| | - Xinxing Lv
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, Shandong, People’s Republic of China
| | - Xiangfeng Meng
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, Shandong, People’s Republic of China
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, Shandong, People’s Republic of China
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Wei H, Wu M, Fan A, Su H. Recombinant protein production in the filamentous fungus Trichoderma. Chin J Chem Eng 2021. [DOI: 10.1016/j.cjche.2020.11.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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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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Zheng F, Yang R, Cao Y, Zhang W, Lv X, Meng X, Zhong Y, Chen G, Zhou Q, Liu W. Engineering Trichoderma reesei for Hyperproduction of Cellulases on Glucose to Efficiently Saccharify Pretreated Corncobs. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:12671-12682. [PMID: 33140639 DOI: 10.1021/acs.jafc.0c04663] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The filamentous fungus Trichoderma reesei (teleomorph Hypocrea jecorina) is widely used as a cellulase producer in the industry. Herein, we describe the rational engineering of the publicly available T. reesei QM9414 strain to achieve a remarkable high-level production of cellulase on glucose. Overexpression of the key cellulase regulator XYR1 by the copper-repressible promoter Ptcu1 was first implemented to achieve a full cellulase production in the context of catabolite repression (CCR) while eliminating the requirement of inducing sugars for enzyme production. The T. reesei bgl1 gene was further overexpressed to compensate for its low β-glucosidase activity on glucose. This overexpression resulted in a 102% increase in FPase activity compared with the CCR-released RUT-C30 strain cultured on Avicel. Moreover, the saccharification efficiency toward pretreated corncob residues by crude enzymes from the engineered strain on glucose increased by 85% compared with that treated by enzymes from RUT-C30 cultivated on Avicel. The engineered T. reesei strain thus shows great potential as a viable alternative to deliver commercial cellulases after further optimization for efficient saccharification of agricultural waste.
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Affiliation(s)
- Fanglin Zheng
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, Shandong 266237, P. R. China
| | - Renfei Yang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, Shandong 266237, P. R. China
| | - Yanli Cao
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, Shandong 266237, P. R. China
| | - Weixin Zhang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, Shandong 266237, P. R. China
| | - Xinxing Lv
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, Shandong 266237, P. R. China
| | - Xiangfeng Meng
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, Shandong 266237, P. R. China
| | - Yaohua Zhong
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, Shandong 266237, P. R. China
| | - Guanjun Chen
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, Shandong 266237, P. R. China
| | - Qingxin Zhou
- Shandong Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing Technology of Shandong Province/Key Laboratory of Novel Food Resources Processing, Ministry of Agriculture and Rural Affairs, Institute of Agro-Food Science and Technology, No.202 Gongye North Road, Jinan 250100, P. R. China
- College of Life Science, Shandong Normal University, No.88 Wenhua East Road, Jinan 250014, P. R. China
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, Shandong 266237, P. R. China
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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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Trichoderma reesei XYR1 activates cellulase gene expression via interaction with the Mediator subunit TrGAL11 to recruit RNA polymerase II. PLoS Genet 2020; 16:e1008979. [PMID: 32877410 PMCID: PMC7467262 DOI: 10.1371/journal.pgen.1008979] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 07/06/2020] [Indexed: 12/22/2022] Open
Abstract
The ascomycete Trichoderma reesei is a highly prolific cellulase producer. While XYR1 (Xylanase regulator 1) has been firmly established to be the master activator of cellulase gene expression in T. reesei, its precise transcriptional activation mechanism remains poorly understood. In the present study, TrGAL11, a component of the Mediator tail module, was identified as a putative interacting partner of XYR1. Deletion of Trgal11 markedly impaired the induced expression of most (hemi)cellulase genes, but not that of the major β-glucosidase encoding genes. This differential involvement of TrGAL11 in the full induction of cellulase genes was reflected by the RNA polymerase II (Pol II) recruitment on their core promoters, indicating that TrGAL11 was required for the efficient transcriptional initiation of the majority of cellulase genes. In addition, we found that TrGAL11 recruitment to cellulase gene promoters largely occurred in an XYR1-dependent manner. Although xyr1 expression was significantly tuned down without TrGAL11, the binding of XYR1 to cellulase gene promoters did not entail TrGAL11. These results indicate that TrGAL11 represents a direct in vivo target of XYR1 and may play a critical role in contributing to Mediator and the following RNA Pol II recruitment to ensure the induced cellulase gene expression. As a model cellulolytic fungus, T. reesei is capable of rapidly producing a large quantity of (hemi)cellulases when appropriate substrates are present. This outstanding characteristic has made T. reesei a prominent producer of cellulase in industry and also a model organism for studying eukaryotic gene expression. The expression of these hydrolytic enzymes encoding genes in T. reesei is precisely regulated at a transcriptional level and controlled by a suite of transcription factors. Among others, the transcription activator XYR1 has been firmly established to be absolutely necessary for activating the expression of almost all cellulase genes. However, the precise mechanism it acts remains largely unknown. In eukaryotes, the multisubunit Mediator complex has been shown to be critical for expression of most, if not all, protein-coding genes by conveying regulatory information to the basal transcription machinery. Here, we find that XYR1 interacts with the Mediator tail module subunit, TrGAL11, which contributes to cellobiohydrolase (cbh) and endoglucanase (eg) genes but not β-glucosidase (bgl) genes expression. Thus, the induced XYR1 binding to cellulase gene promoters led to TrGAL11 and RNA Pol II recruitment to these promoters. These results show that TrGAL11 represents a direct in vivo target of XYR1 and provide evidence for not only the evolutionarily conserved function of Mediator, but also for the existence of some subtle difference in its action to mediate gene expression in different eukaryotes.
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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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Luo Y, Valkonen M, Jackson RE, Palmer JM, Bhalla A, Nikolaev I, Saloheimo M, Ward M. Modification of transcriptional factor ACE3 enhances protein production in Trichoderma reesei in the absence of cellulase gene inducer. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:137. [PMID: 32782473 PMCID: PMC7412840 DOI: 10.1186/s13068-020-01778-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 07/29/2020] [Indexed: 05/31/2023]
Abstract
BACKGROUND Trichoderma reesei is one of the best-known cellulolytic organisms, producing large quantities of a complete set of extracellular cellulases and hemicellulases for the degradation of lignocellulosic substances. Hence, T. reesei is a biotechnically important host and it is used commercially in enzyme production, of both native and foreign origin. Many strategies for producing enzymes in T. reesei rely on the cbh1 and other cellulase gene promoters for high-level expression and these promoters require induction by sophorose, lactose or other inducers for high productivity during manufacturing. RESULTS We described an approach for producing high levels of secreted proteins by overexpression of a transcription factor ACE3 in T. reesei. We refined the ace3 gene structure and identified specific ACE3 variants that enable production of secreted cellulases and hemicellulases on glucose as a sole carbon source (i.e., in the absence of an inducer). These specific ACE3 variants contain a full-length Zn2Cys6 binuclear cluster domain at the N-terminus and a defined length of truncations at the C-terminus. When expressed at a moderate level in the fungal cells, the ACE3 variants can induce high-level expression of cellulases and hemicellulases on glucose (i.e., in the absence of an inducer), and further improve expression on lactose or glucose/sophorose (i.e., in the presence of an inducer). Finally, we demonstrated that this method is applicable to industrial strains and fermentation conditions, improving protein production both in the absence and in the presence of an inducer. CONCLUSIONS This study demonstrates that overexpression of ACE3 variants enables a high level of protein production in the absence of an inducer, and boosts protein production in the presence of an inducer. It is an efficient approach to increase protein productivity and to reduce manufacturing costs.
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Affiliation(s)
- Yun Luo
- DuPont Industrial Biosciences, Genencor Research Center, 925 Page Mill Road, Palo Alto, CA 94304 USA
| | - Mari Valkonen
- VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, FI-02044 VTT Espoo, Finland
| | - Raymond E. Jackson
- DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE 19803 USA
| | - Jonathan M. Palmer
- DuPont Industrial Biosciences, Genencor Research Center, 925 Page Mill Road, Palo Alto, CA 94304 USA
| | - Aditya Bhalla
- DuPont Industrial Biosciences, Genencor Research Center, 925 Page Mill Road, Palo Alto, CA 94304 USA
| | - Igor Nikolaev
- DuPont Industrial Biosciences, Genencor B.V., Willem Einthovenstraat 4, 2342 BH Oegstgeest, The Netherlands
| | - Markku Saloheimo
- VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, FI-02044 VTT Espoo, Finland
| | - Michael Ward
- DuPont Industrial Biosciences, Genencor Research Center, 925 Page Mill Road, Palo Alto, CA 94304 USA
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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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Meng QS, Zhang F, Wang W, Liu CG, Zhao XQ, Bai FW. Engineering the Effector Domain of the Artificial Transcription Factor to Improve Cellulase Production by Trichoderma reesei. Front Bioeng Biotechnol 2020; 8:675. [PMID: 32671045 PMCID: PMC7330100 DOI: 10.3389/fbioe.2020.00675] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 06/01/2020] [Indexed: 11/13/2022] Open
Abstract
Filamentous fungal strains of Trichoderma reesei have been widely used for cellulase production, and great effort has been devoted to enhancing their cellulase titers for the economic biorefinery of lignocellulosic biomass. In our previous studies, artificial zinc finger proteins (AZFPs) with the Gal4 effector domain were used to enhance cellulase biosynthesis in T. reesei, and it is of great interest to modify the AZFPs to further improve cellulase production. In this study, the endogenous activation domain from the transcription activator Xyr1 was used to replace the activation domain of Gal4 of the AZFP to explore impact on cellulase production. The cellulase producer T. reesei TU-6 was used as a host strain, and the engineered strains containing the Xyr1 and the Gal4 activation domains were named as T. reesei QS2 and T. reesei QS1, respectively. Compared to T. reesei QS1, activities of filter paper and endoglucanases in crude cellulase produced by T. reesei QS2 increased 24.6 and 50.4%, respectively. Real-time qPCR analysis also revealed significant up-regulation of major genes encoding cellulase in T. reesei QS2. Furthermore, the biomass hydrolytic performance of the cellulase was evaluated, and 83.8 and 97.9% more glucose was released during the hydrolysis of pretreated corn stover using crude enzyme produced by T. reesei QS2, when compared to the hydrolysis with cellulase produced by T. reesei QS1 and the parent strain T. reesei TU-6. As a result, we proved that the effector domain in the AZFPs can be optimized to construct more effective artificial transcription factors for engineering T. reesei to improve its cellulase production.
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Affiliation(s)
- Qing-Shan Meng
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Fei Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Wei Wang
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Chen-Guang Liu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and 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 and 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 and 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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Meng QS, Zhang F, Liu CG, Zhao XQ, Bai FW. Identification of a novel repressor encoded by the putative gene ctf1 for cellulase biosynthesis in Trichoderma reesei through artificial zinc finger engineering. Biotechnol Bioeng 2020; 117:1747-1760. [PMID: 32124970 DOI: 10.1002/bit.27321] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 02/28/2020] [Accepted: 03/01/2020] [Indexed: 11/09/2022]
Abstract
Strains from Trichoderma reesei have been used for cellulase production with a long history. It has been well known that cellulase biosynthesis by the fungal species is controlled through regulators, and elucidation of their regulation network is of great importance for engineering T. reesei with robust cellulase production. However, progress in this regard is still very limited. In this study, T. reesei RUT-C30 was transformed with an artificial zinc finger protein (AZFP) library, and the mutant T. reesei M2 with improved cellulase production was screened. Compared to its parent strain, the filter paper activity and endo-β-glucanase activity in cellulases produced by T. reesei M2 increased 67.2% and 35.3%, respectively. Analysis by quantitative reverse transcription polymerase chain reaction indicated significant downregulation of the putative gene ctf1 in T. reesei M2, and its deletion mutants were thus developed for further studies. An increase of 36.9% in cellulase production was observed in the deletion mutants, but when ctf1 was constitutively overexpressed in T. reesei RUT-C30 under the control of the strong pdc1 promoter, cellulase production was substantially compromised. Comparative transcriptomic analysis revealed that the deletion of ctf1 upregulated transcription of gene encoding the regulator VIB1, but downregulated transcription of gene encoding another regulator RCE1, which consequently upregulated genes encoding the transcription factors XYR1 and ACE3 for the activation of genes encoding cellulolytic enzymes. As a result, ctf1 was characterized as a gene encoding a repressor for cellulase production in T. reesei RUT-C30, which is significant for further elucidating molecular mechanism underlying cellulase biosynthesis by the fungal species for rational design to develop robust strains for cellulase production. And in the meantime, AZFP transformation was validated to be an effective strategy for identifying functions of putative genes in the genome of T. reesei.
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Affiliation(s)
- Qing-Shan Meng
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Science, and School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Fei Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Science, and School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Chen-Guang Liu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Science, and School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xin-Qing Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Science, and School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Feng-Wu Bai
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Science, and School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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Sun X, Zhang X, Huang H, Wang Y, Tu T, Bai Y, Wang Y, Zhang J, Luo H, Yao B, Su X. Engineering the cbh1 Promoter of Trichoderma reesei for Enhanced Protein Production by Replacing the Binding Sites of a Transcription Repressor ACE1 to Those of the Activators. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:1337-1346. [PMID: 31933359 DOI: 10.1021/acs.jafc.9b05452] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The strong and inducible cbh1 promoter is most widely used to express heterologous proteins, useful in food and feed industries, in Trichoderma reesei. Enhancing its ability to direct transcription provides a general strategy to improve protein production in T. reesei. The cbh1 promoter was engineered by replacing eight binding sites of the transcription repressor ACE1 to those of the activators ACE2, Hap2/3/5, and Xyr1. While changing ACE1 to Hap2/3/5-binding sites completely abolished the transcription ability, replacements with ACE2- and Xyr1-binding sites (designated cbh1pA and cbh1pX promoters, respectively) largely improved the promoter transcription efficiency, as reflected by expression of a reporter gene DsRed. The cbh1pA and cbh1pX promoters were applied to improve secretory expression of a codon-optimized mannanase from Aspergillus niger to 3.6- and 5.0-fold higher, respectively, which has high application potential in feed industry.
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Affiliation(s)
- Xianhua Sun
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Xuhuan Zhang
- Biotechnology Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , People's Republic of China
| | - Huoqing Huang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Yuan Wang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Tao Tu
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Yingguo Bai
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Yaru Wang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Jie Zhang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Huiying Luo
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Bin Yao
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Xiaoyun Su
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
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Novy V, Nielsen F, Seiboth B, Nidetzky B. The influence of feedstock characteristics on enzyme production in Trichoderma reesei: a review on productivity, gene regulation and secretion profiles. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:238. [PMID: 31624500 PMCID: PMC6781402 DOI: 10.1186/s13068-019-1571-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 09/20/2019] [Indexed: 05/21/2023]
Abstract
Biorefineries, designed for the production of lignocellulose-based chemicals and fuels, are receiving increasing attention from the public, governments, and industries. A major obstacle for biorefineries to advance to commercial scale is the high cost of the enzymes required to derive the fermentable sugars from the feedstock used. As summarized in this review, techno-economic studies suggest co-localization and integration of enzyme manufacturing with the cellulosic biorefinery as the most promising alternative to alleviate this problem. Thus, cultivation of Trichoderma reesei, the principal producer of lignocellulolytic enzymes, on the lignocellulosic biomass processed on-site can reduce the cost of enzyme manufacturing. Further, due to a complex gene regulation machinery, the fungus can adjust the gene expression of the lignocellulolytic enzymes towards the characteristics of the feedstock, increasing the hydrolytic efficiency of the produced enzyme cocktail. Despite extensive research over decades, the underlying regulatory mechanisms are not fully elucidated. One aspect that has received relatively little attention in literature is the influence the characteristics of a lignocellulosic substrate, i.e., its chemical and physical composition, has on the produced enzyme mixture. Considering that the fungus is dependent on efficient enzymatic degradation of the lignocellulose for continuous supply of carbon and energy, a relationship between feedstock characteristics and secretome composition can be expected. The aim of this review was to systematically collect, appraise, and aggregate data and integrate results from studies analyzing enzyme production by T. reesei on insoluble cellulosic model substrates and lignocellulosic biomass. The results show that there is a direct effect of the substrate's complexity (rated by structure, composition of the lignin-carbohydrate complex, and recalcitrance in enzymatic saccharification) on enzyme titers and the composition of specific activities in the secretome. It further shows that process-related factors, such as substrate loading and cultivation set-up, are direct targets for increasing enzyme yields. The literature on transcriptome and secretome composition further supports the proposed influence of substrate-related factors on the expression of lignocellulolytic enzymes. This review provides insights into the interrelation between the characteristics of the substrate and the enzyme production by T. reesei, which may help to advance integrated enzyme manufacturing of substrate-specific enzymes cocktails at scale.
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Affiliation(s)
- Vera Novy
- Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Graz University of Technology, Graz, Austria
- Present Address: Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, Canada
| | - Fredrik Nielsen
- Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Graz University of Technology, Graz, Austria
- Present Address: Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, Canada
| | - Bernhard Seiboth
- Institute of Chemical, Environmental and Bioscience Engineering, Vienna University of Technology, Vienna, Austria
- Austrian Centre of Industrial Biotechnology (acib) GmbH, Graz, Austria
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Graz University of Technology, Graz, Austria
- Austrian Centre of Industrial Biotechnology (acib) GmbH, Graz, 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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The GATA-Type Transcriptional Factor Are1 Modulates the Expression of Extracellular Proteases and Cellulases in Trichoderma reesei. Int J Mol Sci 2019; 20:ijms20174100. [PMID: 31443450 PMCID: PMC6747117 DOI: 10.3390/ijms20174100] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 07/20/2019] [Accepted: 08/20/2019] [Indexed: 02/08/2023] Open
Abstract
Trichoderma reesei is a biotechnologically important filamentous fungus with the remarkable ability to secrete large amounts of enzymes, whose production is strongly affected by both the carbon and nitrogen sources. While the carbon metabolism regulators are extensively studied, the regulation of enzyme production by the nitrogen metabolism regulators is still poorly understood. In this study, the GATA transcription factor Are1, which is an orthologue of the Aspergillus global nitrogen regulator AREA, was identified and characterized for its functions in regulation of both protease and cellulase production in T. reesei. Deletion of the are1 gene abolished the capability to secrete proteases, and complementation of the are1 gene rescued the ability to produce proteases. Quantitative RT-PCR analysis revealed that the transcripts of protease genes apw1 and apw2 were also significantly reduced in the Δare1 strain when grown in the medium with peptone as the nitrogen source. In addition, deletion of are1 resulted in decreased cellulase production in the presence of (NH4)2SO4. Consistent with the reduction of cellulase production, the transcription levels of the major cellulase genes, including cbh1, cbh2, egl1, and egl2, were dramatically decreased in Δare1. Sequence analysis showed that all promoter regions of the tested protease and cellulase genes contain the consensus GATA elements. However, the expression levels of the major cellulase transcription activator Xyr1 and the repressor Cre1 had no significant difference between Δare1 and the parental strain QM9414, indicating that the regulatory mechanism deserves further investigation. Taken together, these results demonstrate the important role of Are1 in the regulation of protease and cellulase production in T. reesei, although these processes depend on the kind of nitrogen sources. The findings in this study contribute to the understanding of the regulation network of carbon and nitrogen sources in filamentous fungi.
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Wang L, Yang R, Cao Y, Zheng F, Meng X, Zhong Y, Chen G, Zhang W, Liu W. CLP1, a Novel Plant Homeo Domain Protein, Participates in Regulating Cellulase Gene Expression in the Filamentous Fungus Trichoderma reesei. Front Microbiol 2019; 10:1700. [PMID: 31447796 PMCID: PMC6691364 DOI: 10.3389/fmicb.2019.01700] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Accepted: 07/10/2019] [Indexed: 01/17/2023] Open
Abstract
The stringent regulatory network of cellulase gene expression in the filamentous fungus Trichoderma reesei involves multiple transcriptional regulators. However, identification and mechanistic investigation of these regulators are still insufficient. Here, we identified a novel transcriptional regulator, CLP1, a plant homeo domain (PHD) Protein that participates in regulating T. reesei cellulase gene expression. Phylogenetic analyses demonstrated that CLP1 homologs are widely distributed in filamentous fungi including Trichoderma, Penicillium, Fusarium, Neurospora, and Aspergillus species. We demonstrated that CLP1 is a nuclear protein and lack of CLP1 significantly impaired the induced expression of cellulase genes. ChIP experiments showed CLP1 binding to the cellulase gene promoters specifically under cellulose conditions and compromised XYR1 occupancy on the same promoters in the absence of CLP1 at the early induction stage. XYR1 overexpression fully rescued the defect in cellulase production but not the defect in conidia formation in the clp1 null mutant. Further analysis showed that the PHD is required for the CLP1 appropriate subcellular localization as well as the induced cellulase gene expression and conidiation. Taken together, these data demonstrated an important role of CLP1 in the regulation of cellulase and xylanase gene expression in T. reesei.
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Affiliation(s)
- Lei Wang
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Renfei Yang
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Yanli Cao
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Fanglin Zheng
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Xiangfeng Meng
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Yaohua Zhong
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Guanjun Chen
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Weixin Zhang
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
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