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Chan Ho Tong L, Jourdier E, Naquin D, Ben Chaabane F, Aouam T, Chartier G, Castro González I, Margeot A, Bidard F. Transgressive phenotypes from outbreeding between the Trichoderma reesei hyper producer RutC30 and a natural isolate. Microbiol Spectr 2024; 12:e0044124. [PMID: 39162516 PMCID: PMC11448445 DOI: 10.1128/spectrum.00441-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 07/03/2024] [Indexed: 08/21/2024] Open
Abstract
Trichoderma reesei, the main filamentous fungus used for industrial cellulase production, was long considered to be asexual. The recent discovery of the mating type locus in the natural isolate QM6a and the possibility to cross this sterile female strain with a fertile natural female strain opened up a new avenue for strain optimization. We crossed the hyperproducer RutC30 with a compatible female ascospore-derived isolate of the wild-type strain CBS999.97 and analyzed about 300 offspring. A continuous distribution of secreted protein levels was observed in the progeny, confirming the involvement of several mutated loci in the hyperproductive phenotype. A bias toward MAT1-2 strains was identified for higher producers, but not directly linked to the Mating-type locus itself. Transgressive phenotypes were observed in terms of both productivity and secretome quality, with offspring that outperform their parents for three enzymatic activities. Genomic sequences of the 10 best producers highlighted the genetic diversity generated and the involvement of parental alleles in hyperproduction and fertility. IMPORTANCE The filamentous fungus Trichoderma reesei produces cellulolytic enzymes that are essential for the hydrolysis of lignocellulosic biomass into monomerics sugars. The filamentous fungus T. reesei produces cellulolytic enzymes that are essential for the hydrolysis of lignocellulosic biomass into monomerics sugars, which can in turn be fermented to produce second-generation biofuels and bioproducts. Production performance improvement, which is essential to reduce production cost, relies on classical mutagenesis and genetic engineering techniques. Although sexual reproduction is a powerful tool for improving domesticated species, it is often difficult to apply to industrial fungi since most of them are considered asexual. In this study, we demonstrated that outbreeding is an efficient strategy to optimize T. reesei. Crossing between a natural isolate and a mutagenized strain generated a biodiverse progeny with some offspring displaying transgressive phenotype for cellulase activities.
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Affiliation(s)
- Laetitia Chan Ho Tong
- Biotechnology Department, IFP Energies nouvelles (IFPEN), 92852 Rueil-Malmaison, France
| | - Etienne Jourdier
- Biotechnology Department, IFP Energies nouvelles (IFPEN), 92852 Rueil-Malmaison, France
| | - Delphine Naquin
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France
| | - Fadhel Ben Chaabane
- Biotechnology Department, IFP Energies nouvelles (IFPEN), 92852 Rueil-Malmaison, France
| | - Thiziri Aouam
- Biotechnology Department, IFP Energies nouvelles (IFPEN), 92852 Rueil-Malmaison, France
| | - Gwladys Chartier
- Biotechnology Department, IFP Energies nouvelles (IFPEN), 92852 Rueil-Malmaison, France
| | - Itzel Castro González
- Biotechnology Department, IFP Energies nouvelles (IFPEN), 92852 Rueil-Malmaison, France
| | - Antoine Margeot
- Biotechnology Department, IFP Energies nouvelles (IFPEN), 92852 Rueil-Malmaison, France
| | - Frederique Bidard
- Biotechnology Department, IFP Energies nouvelles (IFPEN), 92852 Rueil-Malmaison, France
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Ran X, Gao Y, He X, Wang Z, Mo Y, Li Y. Enhanced glucose-1-phosphate production from corn stover using cellulases with reduced β-glucosidase activity via Trbgl1 gene knockout in Trichoderma reesei Rut C30. Enzyme Microb Technol 2024; 180:110503. [PMID: 39208708 DOI: 10.1016/j.enzmictec.2024.110503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Revised: 07/30/2024] [Accepted: 08/20/2024] [Indexed: 09/04/2024]
Abstract
The scarcity of cellulases with low β-glucosidase activity poses a significant technological challenge in precisely controlling the partial hydrolysis of lignocellulose to cellobiose, crucial for producing high-value chemicals such as starch, inositol, and NMN. Trichoderma reesei is a primary strain in cellulase production. Therefore, this study targeted the critical β-glucosidase gene, Trbgl1, resulting in over an 86 % reduction in β-glucosidase activity. However, cellulase production decreased by 19.2 % and 20.3 % with lactose or cellulose inducers, respectively. Notably, transcript levels of cellulase genes and overall yield remained unaffected with an inducer containing sophorose. This indicates that β-glucosidase BGL1 converts lactose or cellulose to sophorose through transglycosylation activity, inducing cellulase gene transcription. The resulting enzyme cocktail, comprising recombinant cellulase and cellobiose phosphorylase, was applied for corn stover hydrolysis, resulting in a 24.3 % increase in glucose-1-phosphate yield. These findings provide valuable insights into obtaining enzymes suitable for the high-value utilization of lignocellulose.
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Affiliation(s)
- Xiaoqin Ran
- School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology, Chongqing 401331, China
| | - Yushan Gao
- School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology, Chongqing 401331, China
| | - Xiao He
- School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology, Chongqing 401331, China
| | - Zancheng Wang
- School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology, Chongqing 401331, China
| | - Yi Mo
- School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology, Chongqing 401331, China
| | - Yonghao Li
- School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology, Chongqing 401331, China.
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Kislitsin VY, Chulkin AM, Dotsenko AS, Sinelnikov IG, Sinitsyn AP, Rozhkova AM. The role of intracellular β-glucosidase in cellulolytic response induction in filamentous fungus Penicillium verruculosum. Res Microbiol 2024; 175:104178. [PMID: 38160731 DOI: 10.1016/j.resmic.2023.104178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 12/25/2023] [Accepted: 12/26/2023] [Indexed: 01/03/2024]
Abstract
In this study, CRISPR/Cas9 genome editing was used to knockout the bgl2 gene encoding intracellular β-glucosidase filamentous fungus Penicillium verruculosum. This resulted in a dramatic reduction of secretion of cellulolytic enzymes. The study of P. verruculosum Δbgl2 found that the transcription of the cbh1 gene, which encodes cellobiohydrolase 1, was impaired when induced by cellobiose and cellotriose. However, the transcription of the cbh1 gene remains at level of the host strain when induced by gentiobiose. This implies that gentiobiose is the true inducer of the cellulolytic response in P. verruculosum, in contrast to Neurospora crassa where cellobiose acts as an inducer.
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Affiliation(s)
- Valeriy Yu Kislitsin
- FSI Federal Research Centre Fundamentals of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russia.
| | - Andrey M Chulkin
- FSI Federal Research Centre Fundamentals of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russia.
| | - Anna S Dotsenko
- FSI Federal Research Centre Fundamentals of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russia.
| | - Igor G Sinelnikov
- FSI Federal Research Centre Fundamentals of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russia.
| | - Arkady P Sinitsyn
- FSI Federal Research Centre Fundamentals of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russia; Faculty of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia.
| | - Aleksandra M Rozhkova
- FSI Federal Research Centre Fundamentals of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russia.
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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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Wang Z, Yang R, Lv W, Zhang W, Meng X, Liu W. Functional Characterization of Sugar Transporter CRT1 Reveals Differential Roles of Its C-Terminal Region in Sugar Transport and Cellulase Induction in Trichoderma reesei. Microbiol Spectr 2022; 10:e0087222. [PMID: 35852347 PMCID: PMC9431493 DOI: 10.1128/spectrum.00872-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 07/04/2022] [Indexed: 11/28/2022] Open
Abstract
The expression of cellulase genes in lignocellulose-degrading fungus Trichoderma reesei is induced by insoluble cellulose and its soluble derivatives. Membrane-localized transporter/transceptor proteins have been thought to be involved in nutrient uptake and/or sensing to initiate the subsequent signal transduction during cellulase gene induction. Crt1 is a sugar transporter proven to be essential for cellulase gene induction although the detailed mechanism of Crt1-triggered cellulase induction remains elusive. In this study, we focused on the C-terminus region of Crt1 which is predicted to exist as an unstructured cytoplasmic tail in T. reesei. Serial C-terminal truncation of Crt1 revealed that deleting the last half of the C-terminal region of Crt1 hardly affected its transporting activity or ability to mediate the induction of cellulase gene expression. In contrast, removal of the entire C-terminus region eliminated both activities. Of note, Crt1-C5, retaining only the first five amino acids of C-terminus, was found to be capable of transporting lactose but failed to restore cellulase gene induction in the Δcrt1 strain. Analysis of the cellular localization of Crt1 showed that Crt1 existed both at the plasma membrane and at the periphery of the nucleus although the functional relevance is not clear at present. Finally, we showed that the cellulase production defect of Δcrt1 was corrected by overexpressing Xyr1, indicating that Xyr1 is a potential regulatory target of the signaling cascade initiated from Crt1. IMPORTANCE The lignocellulose-degrading fungus T. reesei has been widely used in industrial cellulases production. Understanding the precise cellulase gene regulatory network is critical for its genetic engineering to enhance the mass production of cellulases. As the key membrane protein involved in cellulase expression in T. reesei, the detailed mechanism of Crt1 in mediating cellulase induction remains to be investigated. In this study, the C-terminal region of Crt1 was found to be vital for its transport and signaling receptor functions. These two functions are, however, separable because a C-terminal truncation mutant is capable of sugar transporting but loses the ability to mediate cellulase gene expression. Furthermore, the key transcriptional activator Xyr1 represents a downstream target of the Crt1-initiated signaling cascade. Together, our research provides new insights into the function of Crt1 and further contributes to the unveiling of the intricate signal transduction process leading to efficient cellulase gene expression in T. reesei.
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Affiliation(s)
- Zhixing Wang
- State Key Laboratory of Microbial Technology, Microbiology Technology Institute, Shandong University, Qingdao, People’s Republic of China
| | - Renfei Yang
- State Key Laboratory of Microbial Technology, Microbiology Technology Institute, Shandong University, Qingdao, People’s Republic of China
| | - Wenhao Lv
- State Key Laboratory of Microbial Technology, Microbiology Technology Institute, Shandong University, Qingdao, People’s Republic of China
| | - Weixin Zhang
- State Key Laboratory of Microbial Technology, Microbiology Technology Institute, Shandong University, Qingdao, People’s Republic of China
| | - Xiangfeng Meng
- State Key Laboratory of Microbial Technology, Microbiology Technology Institute, Shandong University, Qingdao, People’s Republic of China
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, Microbiology Technology Institute, Shandong University, Qingdao, People’s Republic of China
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Zhang P, Li Q, Chen Y, Peng N, Liu W, Wang X, Li Y. Induction of cellulase production in Trichoderma reesei by a glucose-sophorose mixture as an inducer prepared using stevioside. RSC Adv 2022; 12:17392-17400. [PMID: 35765440 PMCID: PMC9190947 DOI: 10.1039/d2ra01192a] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 06/03/2022] [Indexed: 11/28/2022] Open
Abstract
Sophorose is currently the most effective inducer of cellulase production by Trichoderma reesei; however, the use of byproduct sophorose from the stevioside acid hydrolysis process has not been developed. In this study, stevioside was hydrolysed with different concentrations of HCl to obtain isosteviol and a mixture of glucose and sophorose (MGS). Isosteviol showed good inhibitory effects on the growth of Aspergillus niger, Saccharomyces cerevisiae and Escherichia coli after separation. At the same time, MGS, as a byproduct, was evaluated for cellulase production to determine the feasibility of this approach. MGS was compared with common soluble inducers, such as lactose, cellobiose, and a mixture of glucose and β-disaccharide (MGD), and induced higher cellulase production than the other inducers. The cellulase activity induced by MGS was 1.64- and 5.26-fold higher than that induced by lactose and cellobiose, respectively, and was not significantly different from that induced by MGD. The crude enzyme using MGS as an inducer with commercial β-glucosidase was further tested by hydrolyzing NaOH-pretreated corn stover with 5% solid loading, and 33.4 g L-1 glucose was released with a glucose yield of 96.04%. The strategy developed in this work will be beneficial for reducing inducer production cost through a simple stevia glycoside hydrolysis reaction and will contribute to studies aimed at improving cellulase production using soluble inducers for easier operation in industrial-scale cellulase production.
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Affiliation(s)
- Peng Zhang
- Chongqing Key Laboratory of Industrial Fermentation Microorganism, School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology Chongqing 401331 China +86-23-65022211
| | - Qian Li
- Chongqing Key Laboratory of Industrial Fermentation Microorganism, School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology Chongqing 401331 China +86-23-65022211
| | - Yudian Chen
- Chongqing Key Laboratory of Industrial Fermentation Microorganism, School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology Chongqing 401331 China +86-23-65022211
| | - Nian Peng
- Chongqing Key Laboratory of Industrial Fermentation Microorganism, School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology Chongqing 401331 China +86-23-65022211
| | - Wenshu Liu
- Chongqing Key Laboratory of Industrial Fermentation Microorganism, School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology Chongqing 401331 China +86-23-65022211
| | - Xuemei Wang
- Chongqing Key Laboratory of Industrial Fermentation Microorganism, School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology Chongqing 401331 China +86-23-65022211
| | - Yonghao Li
- Chongqing Key Laboratory of Industrial Fermentation Microorganism, School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology Chongqing 401331 China +86-23-65022211
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Pang AP, Luo Y, Hu X, Zhang F, Wang H, Gao Y, Durrani S, Li C, Shi X, Wu FG, Li BZ, Lu Z, Lin F. Transmembrane transport process and endoplasmic reticulum function facilitate the role of gene cel1b in cellulase production of Trichoderma reesei. Microb Cell Fact 2022; 21:90. [PMID: 35590356 PMCID: PMC9118834 DOI: 10.1186/s12934-022-01809-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 04/30/2022] [Indexed: 11/16/2022] Open
Abstract
Background A total of 11 β-glucosidases are predicted in the genome of Trichoderma reesei, which are of great importance for regulating cellulase biosynthesis. Nevertheless, the relevant function and regulation mechanism of each β-glucosidase remained unknown. Results We evidenced that overexpression of cel1b dramatically decreased cellulase synthesis in T. reesei RUT-C30 both at the protein level and the mRNA level. In contrast, the deletion of cel1b did not noticeably affect cellulase production. Protein CEL1B was identified to be intracellular, being located in vacuole and cell membrane. The overexpression of cel1b reduced the intracellular pNPGase activity and intracellular/extracellular glucose concentration without inducing carbon catabolite repression. On the other hand, RNA-sequencing analysis showed the transmembrane transport process and endoplasmic reticulum function were affected noticeably by overexpressing cel1b. In particular, some important sugar transporters were notably downregulated, leading to a compromised cellular uptake of sugars including glucose and cellobiose. Conclusions Our data suggests that the cellulase inhibition by cel1b overexpression was not due to the β-glucosidase activity, but probably the dysfunction of the cellular transport process (particularly sugar transport) and endoplasmic reticulum (ER). These findings advance the knowledge of regulation mechanism of cellulase synthesis in filamentous fungi, which is the basis for rationally engineering T. reesei strains to improve cellulase production in industry. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-022-01809-1.
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Affiliation(s)
- Ai-Ping Pang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Yongsheng Luo
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Xin Hu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Funing Zhang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Haiyan Wang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Yichen Gao
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Samran Durrani
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Chengcheng Li
- International Innovation Center for Forest Chemicals and Materials and Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, 210037, China
| | - Xiaotong Shi
- International Innovation Center for Forest Chemicals and Materials and Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, 210037, China
| | - Fu-Gen Wu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Bing-Zhi Li
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Zuhong Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China.
| | - Fengming Lin
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China.
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Regulation of β-Disaccharide Accumulation by β-Glucosidase Inhibitors to Enhance Cellulase Production in Trichoderma reesei. FERMENTATION-BASEL 2022. [DOI: 10.3390/fermentation8050232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Trichoderma reesei is a high-yield producer of cellulase for applications in lignocellulosic biomass conversion, but its cellulase production requires induction. A mixture of glucose and β-disaccharide has been demonstrated to achieve high-level cellulase production. However, as inducers, β-disaccharides are prone to be hydrolyzed by β-glucosidase (BGL) during fermentation, therefore β-disaccharides need to be supplemented through feeding to overcome this problem. Here, miglitol, an α-glucosidase inhibitor, was investigated as a BGL inhibitor, and exhibited an IC50 value of 2.93 μg/mL. The cellulase titer was more than two-fold when miglitol was added to the fermentation medium of T. reesei. This method was similar to the prokaryotic expression system using unmetabolized isopropyl-β-D-thiogalactopyranoside (IPTG) as the inducer instead of lactose to continuously induce gene expression. However, cellulase activity was not enhanced with BGL inhibition when lactose or cellulose was used as an inducer, which demonstrated that the transglycosidase activity of BGL is important for the inducible activity of lactose and cellulose. This novel method demonstrates potential in stimulating cellulase production and provides a promising system for T. reesei protein expression.
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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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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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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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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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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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15
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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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Mohamad Sobri MF, Abd-Aziz S, Abu Bakar FD, Ramli N. In-Silico Characterization of Glycosyl Hydrolase Family 1 β-Glucosidase from Trichoderma asperellum UPM1. Int J Mol Sci 2020; 21:ijms21114035. [PMID: 32512945 PMCID: PMC7311958 DOI: 10.3390/ijms21114035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 04/22/2020] [Accepted: 04/30/2020] [Indexed: 11/16/2022] Open
Abstract
β-glucosidases (Bgl) are widely utilized for releasing non-reducing terminal glucosyl residues. Nevertheless, feedback inhibition by glucose end product has limited its application. A noticeable exception has been found for β-glucosidases of the glycoside hydrolase (GH) family 1, which exhibit tolerance and even stimulation by glucose. In this study, using local isolate Trichoderma asperellum UPM1, the gene encoding β-glucosidase from GH family 1, hereafter designated as TaBgl2, was isolated and characterized via in-silico analyses. A comparison of enzyme activity was subsequently made by heterologous expression in Escherichia coli BL21(DE3). The presence of N-terminal signature, cis-peptide bonds, conserved active site motifs, non-proline cis peptide bonds, substrate binding, and a lone conserved stabilizing tryptophan (W) residue confirms the identity of Trichoderma sp. GH family 1 β-glucosidase isolated. Glucose tolerance was suggested by the presence of 14 of 22 known consensus residues, along with corresponding residues L167 and P172, crucial in the retention of the active site's narrow cavity. Retention of 40% of relative hydrolytic activity on ρ-nitrophenyl-β-D-glucopyranoside (ρNPG) in a concentration of 0.2 M glucose was comparable to that of GH family 1 β-glucosidase (Cel1A) from Trichoderma reesei. This research thus underlines the potential in the prediction of enzymatic function, and of industrial importance, glucose tolerance of family 1 β-glucosidases following relevant in-silico analyses.
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Affiliation(s)
- Mohamad Farhan Mohamad Sobri
- Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400 UPM, Selangor, Malaysia; (M.F.M.S.); (S.A.-A.)
- School of Bioprocess Engineering, Universiti Malaysia Perlis, Kompleks Pusat Pengajian Jejawi 3, Arau 02600, Perlis, Malaysia
| | - Suraini Abd-Aziz
- Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400 UPM, Selangor, Malaysia; (M.F.M.S.); (S.A.-A.)
| | - Farah Diba Abu Bakar
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600 UKM, Selangor, Malaysia;
| | - Norhayati Ramli
- Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400 UPM, Selangor, Malaysia; (M.F.M.S.); (S.A.-A.)
- Correspondence: ; Tel.: +60-3-9769-1948
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Cao Y, Zheng F, Zhang W, Meng X, Liu W. Trichoderma reesei XYR1 recruits SWI/SNF to facilitate cellulase gene expression. Mol Microbiol 2019; 112:1145-1162. [PMID: 31309604 DOI: 10.1111/mmi.14352] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/09/2019] [Indexed: 12/20/2022]
Abstract
Cellulase gene expression in Trichoderma reesei is highly responsive to environmental cues and is under stringent regulation by multiple transcription factors. XYR1 (Xylanase regulator 1) has been identified as the most important transcriptional activator of cellulase/hemicellulase gene expression although the precise transactivating mechanism remains largely elusive. Here we show that the activation domain of XYR1 interacts with the T. reesei homolog of the TrSNF12 subunit of SWI/SNF complex. Deletion of Trsnf12 markedly impaired the induced cellulase gene expression. Individual loss of other SWI/SNF subunits including the catalytic subunit also severely compromised cellulase gene expression and interfered with loss of histone H4 in the cbh1 and eg1 promoters upon cellulose induction. In addition, we find that the SWI/SNF occupancy on cellulase gene promoters strictly required XYR1 and TrSNF12 but TrSNF12 was dispensable for the XYR1 binding to these promoters. These data suggest a model in which XYR1 recruits SWI/SNF through direct interactions with TrSNF12 to remodel chromatin at cellulase gene promoters, thereby activating cellulase gene expression to initiate the cellulolytic response in T. reesei.
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Affiliation(s)
- Yanli Cao
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao, 266237, People's Republic of China
| | - Fanglin Zheng
- 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
| | - Xiangfeng Meng
- 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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18
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Abdeljalil S, Borgi I, Carvalho S, Jmal-Hammami L, Gargouri A. Molecular and bioinformatics analyses reveal two differentially expressed intracellular GH1 β-glucosidases from the rare alkalophilic fungus Stachybotrys microspora. Gene 2019; 703:134-144. [PMID: 30974199 PMCID: PMC6525110 DOI: 10.1016/j.gene.2019.04.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 03/06/2019] [Accepted: 04/02/2019] [Indexed: 01/25/2023]
Abstract
The present study reports the isolation and analysis of two novel GH1 β-glucosidases from the alkalophilic fungus Stachybotrys microspora, using PCR and Nested-PCR. Three major gene fragments were obtained by PCR: the first two are very similar and constitute a novel gene, which was named Smbgl1A, and the third PCR fragment is part of a different gene, named Smbgl1B. The truncated gene sequences were completely filled using the recent partial whole genome sequencing data of S. microspora (data not yet published). Moreover, we investigated the relative effects of glucose in comparison to cellulose rather than evaluate their absolute effects. In fact, RT-PCR analysis showed that while Smbgl1A was expressed when the fungus was grown in the presence of cellulose but not when grown with glucose, Smbgl1B was equally expressed under both conditions. The putative catalytic residues and the conserved glycone binding sites were identified. Zymogram analysis showed the intracellular production of β-glucosidases in S. microspora. The predicted secondary structure exhibited a classical (β/α)8 barrel fold, showing that both SmBGL1A and SmBGL1B belong to the GH1 family. Phylogenetic studies showed that SmBGL1A and SmBGL1B belong to the same branch as β-glucosidases from Stachybotrys chlorohalonata and Stachybotrys chartarum. However, SmBGL1A and SmBGL1B form two distinct clades. Isolation of two novel GH 1 β-glucosidases from Stachybotrys microspora Investigation of the relative effects of glucose in comparison to cellulose Zymogram analysis has shown the intracellular production of GH1 β-glucosidases. Prediction of the secondary structure with the presence of a classical (β/α) 8 barrel
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Affiliation(s)
- Salma Abdeljalil
- Laboratory of Molecular Biotechnology of Eucaryotes, Centre of Biotechnology of Sfax, Road of Sidi Mansour, B.O 1177, 3018, University of Sfax, Tunisia.
| | - Ines Borgi
- Laboratory of Molecular Biotechnology of Eucaryotes, Centre of Biotechnology of Sfax, Road of Sidi Mansour, B.O 1177, 3018, University of Sfax, Tunisia
| | - Sandra Carvalho
- Mode of Action Group, Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland, UK
| | - Lamia Jmal-Hammami
- Laboratory of Molecular Biotechnology of Eucaryotes, Centre of Biotechnology of Sfax, Road of Sidi Mansour, B.O 1177, 3018, University of Sfax, Tunisia
| | - Ali Gargouri
- Laboratory of Molecular Biotechnology of Eucaryotes, Centre of Biotechnology of Sfax, Road of Sidi Mansour, B.O 1177, 3018, University of Sfax, Tunisia
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Zhang F, Bunterngsook B, Li JX, Zhao XQ, Champreda V, Liu CG, Bai FW. Regulation and production of lignocellulolytic enzymes from Trichoderma reesei for biofuels production. ADVANCES IN BIOENERGY 2019. [DOI: 10.1016/bs.aibe.2019.03.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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20
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Cow manure as a lignocellulosic substrate for fungal cellulase expression and bioethanol production. AMB Express 2018; 8:190. [PMID: 30498944 PMCID: PMC6265361 DOI: 10.1186/s13568-018-0720-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Accepted: 11/23/2018] [Indexed: 11/10/2022] Open
Abstract
Conversion of various lignocellulosic materials into bioethanol is growing in demand but greatly depends on feedstock availability. Dairy cow manure is an agricultural waste widely distributed worldwide. This study investigated the induction of cellulases by cow manure and the conversion of cow manure materials into lignocellulosic ethanol. Alkaline NaOH pretreatment improved the accessibility of cow manure lignocellulose to enzymes followed by enzymatic hydrolysis using Penicillium oxalicum cellulases. The ethanol yields from pretreated cow manure and anaerobically digested cow manure were 0.19 and 0.13 g/g-raw biomass, respectively, using recombinant Saccharomyces cerevisiae strain LF1 designed for lignocellulosic ethanol production through simultaneous saccharification and fermentation. Fed-batch supplementation with cellulolytic enzymes and substrates after initial enzymatic hydrolysis also contributed to ethanol production up to 25.65 g/L. These results demonstrate that cow manure is a potential feedstock for inducing fungal cellulase expression and converting lignocellulose into bioethanol.
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Zou G, Jiang Y, Liu R, Zhu Z, Zhou Z. The putative β-glucosidase BGL3I regulates cellulase induction in Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:314. [PMID: 30473732 PMCID: PMC6240962 DOI: 10.1186/s13068-018-1314-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 11/08/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND The filamentous fungus Trichoderma reesei (anamorph of Hypocrea jecorina) displays increased cellulase expression while growing on inducers such as lactose or cellulose. However, the mechanism of cellulase induction in T. reesei is not yet completely characterized. Here, a protein annotated as β-glucosidase (BGL3I) was found to be involved in cellulase induction in T. reesei. The effects of BGL3I on cellulase production have not yet been fully understood. RESULTS Deletion of the bgl3i gene had no influence on the growth of T. reesei, but significantly increased its cellulase activities. Deletion of bgl3i also resulted in decreased extracellular galactosidase activity, but significantly increased transcription of lactose permeases, which might be involved in lactose transport. Furthermore, deletion of bgl3i enhanced the transcription levels of intracellular β-glucosidases cel1a, cel1b and the regulator xyr1, which are all essential for lactose induction in T. reesei. BGL3I was found to have a relatively high ability to hydrolyze sophorose, which is proposed to be the strongest natural inducer of cellulase synthesis in T. reesei. CONCLUSIONS BGL3I may take part in the complex regulating system of cellulase induction. The deletion of bgl3i offers a new strategy to improve T. reesei strain performance.
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Affiliation(s)
- Gen Zou
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Rd, Shanghai, 200032 China
- Shanghai Key Laboratory of Agricultural Genetics and Breeding; Institute of Edible Fungi, Shanghai Academy of Agriculture Science, 1000 Jinqi Rd, Fengxian, 201403 Shanghai China
| | - Yanping Jiang
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Rd, Shanghai, 200032 China
- Southwest Jiaotong University, Chengdu, 611756 Sichuan China
| | - Rui Liu
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Rd, Shanghai, 200032 China
| | - Zhihua Zhu
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Rd, Shanghai, 200032 China
| | - Zhihua Zhou
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Rd, Shanghai, 200032 China
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Molecular Characterization and Potential Synthetic Applications of GH1 β-Glucosidase from Higher Termite Microcerotermes annandalei. Appl Biochem Biotechnol 2018; 186:877-894. [PMID: 29779183 DOI: 10.1007/s12010-018-2781-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/08/2018] [Indexed: 10/16/2022]
Abstract
A novel β-glucosidase from higher termite Microcerotermes annandalei (MaBG) was obtained via a screening method targeting β-glucosidases with increased activities in the presence of glucose. The purified natural MaBG showed a subunit molecular weight of 55 kDa and existed in a native form as a dimer without any glycosylation. Gene-specific primers designed from its partial amino acid sequences were used to amplify the corresponding 1,419-bp coding sequence of MaBG which encodes a 472-amino acid glycoside hydrolase family 1 (GH1) β-glucosidase. When expressed in Komagataella pastoris, the recombinant MaBG appeared as a ~ 55-kDa protein without glycosylation modifications. Kinetic parameters as well as the lack of secretion signal suggested that MaBG is an intracellular enzyme and not involved in cellulolysis. The hydrolytic activities of MaBG were enhanced in the presence of up to 3.5-4.5 M glucose, partly due to its strong transglucosylation activity, which suggests its applicability in biosynthetic processes. The potential synthetic activities of the recombinant MaBG were demonstrated in the synthesis of para-nitrophenyl-β-D-gentiobioside via transglucosylation and octyl glucoside via reverse hydrolysis. The information obtained from this study has broadened our insight into the functional characteristics of this variant of termite GH1 β-glucosidase and its applications in bioconversion and biotechnology.
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Wang L, Zheng F, Zhang W, Zhong Y, Chen G, Meng X, Liu W. A copper-controlled RNA interference system for reversible silencing of target genes in Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:33. [PMID: 29449881 PMCID: PMC5806297 DOI: 10.1186/s13068-018-1038-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 02/01/2018] [Indexed: 05/25/2023]
Abstract
BACKGROUND Trichoderma reesei is a primary lignocellulosic enzyme producer in industry. However, the mechanisms underlying cellulase synthesis as well as other physiological processes are insufficiently understood partly due to the sophisticated process for its genetic manipulation. Target gene knockdown by RNA interference (RNAi) is a powerful tool for genetic research and biotechnology in eukaryotes including filamentous fungi. Previously reported RNAi system in T. reesei was either uncontrollable or only applicable in certain nutrition state. RESULTS In the present study, we incorporated the copper-responsive tcu1 promoter into an RNAi-mediated silencing system to develop a controllable RNAi-mediated silencing system in T. reesei. As the proof-of-concept, a prototrophic pyr4 gene, highly expressed cel7a and xyr1 genes induced by Avicel and a fab1 gene, whose knockout has proved to be intractable, were successfully knocked down in the absence of copper when the respective RNAi fragment was expressed. Importantly, the phenotype of RNAi strains was shown to be reversed easily to mimic the complementation for excluding any unwanted effects resulted from the random integration of the hpRNA cassette by adding copper in the media. Thus, this controllable RNAi-mediated silencing system can be turned on and turned off only depending on the absence and presence of copper ions in the media, respectively, and not on the nutritional states. CONCLUSIONS The copper-controlled RNA interference system represents an effective tool for reversible silencing of target genes in T. reesei. This reported strategy to conditionally knock down or turn off genes will contribute to our understanding of T. reesei gene functions, especially those that are difficult to be knocked out due to various reasons. In addition, this simple and cost-effective method holds great potential for the application in synthetic biology and genetic engineering of T. reesei.
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Affiliation(s)
- Lei Wang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No.27 Shanda South Road, Jinan, 250100 Shandong People’s Republic of China
| | - Fanglin Zheng
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No.27 Shanda South Road, Jinan, 250100 Shandong People’s Republic of China
| | - Weixin Zhang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No.27 Shanda South Road, Jinan, 250100 Shandong People’s Republic of China
| | - Yaohua Zhong
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No.27 Shanda South Road, Jinan, 250100 Shandong People’s Republic of China
| | - Guanjun Chen
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No.27 Shanda South Road, Jinan, 250100 Shandong People’s Republic of China
| | - Xiangfeng Meng
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No.27 Shanda South Road, Jinan, 250100 Shandong People’s Republic of China
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No.27 Shanda South Road, Jinan, 250100 Shandong People’s Republic of China
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The mating type locus protein MAT1-2-1 of Trichoderma reesei interacts with Xyr1 and regulates cellulase gene expression in response to light. Sci Rep 2017; 7:17346. [PMID: 29229981 PMCID: PMC5725425 DOI: 10.1038/s41598-017-17439-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 11/27/2017] [Indexed: 12/17/2022] Open
Abstract
Cellulase production in the model cellulolytic fungus Trichoderma reesei is subject to a variety of environmental and physiological conditions involving an intricate regulatory network with multiple transcription factors. Here, we identified the mating type locus protein MAT1-2-1 as an interacting partner for the key transcriptional activator Xyr1 of T. reesei cellulase genes. Yeast two-hybrid and GST pulldown analyses revealed that MAT1-2-1 directly interacted with the putative transcription activation domain (AD, 767~940 aa) and the middle homology region (MHR2, 314~632 aa) of Xyr1. Disruption of the mat1-2-1 gene compromised the induced expression of cellulase genes with Avicel in response to light or with lactose. Chromatin immunoprecipitation (ChIP) demonstrated that MAT1-2-1 was recruited to the cbh1 (cellobiohydrolase 1-encoding) gene promoter in a Xyr1-dependent manner. These results strongly support an important role of MAT1-2-1 as a physiological cofactor of Xyr1, and suggest that MAT1-2-1 represents another regulatory node that integrates the light response with carbon source signaling to fine tune cellulase gene transcription.
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Analysis of Light- and Carbon-Specific Transcriptomes Implicates a Class of G-Protein-Coupled Receptors in Cellulose Sensing. mSphere 2017; 2:mSphere00089-17. [PMID: 28497120 PMCID: PMC5425790 DOI: 10.1128/msphere.00089-17] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 04/14/2017] [Indexed: 01/16/2023] Open
Abstract
In fungi, most metabolic processes are subject to regulation by light. For Trichoderma reesei, light-dependent regulation of cellulase gene expression is specifically shown. Therefore, we intended to unravel the relationship between regulation of enzymes by the carbon source and regulation of enzymes by light. Our two-dimensional analysis included inducing and repressing carbon sources which we used to compare light-specific regulation to dark-specific regulation and to rule out effects specific for a single carbon source. We found close connections with respect to gene regulation as well as significant differences in dealing with carbon in the environment in light and darkness. Moreover, our analyses showed an intricate regulation mechanism for substrate degradation potentially involving surface sensing and provide a basis for knowledge-based screening for strain improvement. In fungi, most metabolic processes are subject to regulation by light. Trichoderma reesei is adapted to degradation of plant cell walls and regulates production of the required enzymes in a manner dependent on the nutrient source and the light status. Here we investigated the interrelated relevance of two regulation levels of the transcriptome of T. reesei: light regulation and carbon source-dependent control. We show that the carbon source (cellulose, lactose, sophorose, glucose, or glycerol) is the major source of variation, with light having a modulating effect on transcript regulation. A total of 907 genes were regulated under cellulase-inducing conditions in light, and 947 genes were regulated in darkness, with 530 genes overlapping (1,324 in total). Only 218 of the 1,324 induction-specific genes were independent of light and not regulated by the BLR1, BLR2, and ENV1 photoreceptors. Analysis of the genomic distribution of genes regulated by light upon growth on cellulose revealed considerable overlap of light-regulated clusters with induction-specific clusters and carbohydrate-active enzyme (CAZyme) clusters. Further, we found evidence for the operation of a sensing mechanism for solid cellulosic substrates, with regulation of genes such as swo1, cip1, and cip2 or of genes encoding hydrophobins which is related to the cyclic AMP (cAMP)-dependent regulatory output of ENV1. We identified class XIII G-protein-coupled receptors (GPCRs) CSG1 and CSG2 in T. reesei as putative cellulose/glucose-sensing GPCRs. Our data indicate that the cellulase regulation pathway is bipartite, comprising a section corresponding to transcriptional regulation and one corresponding to posttranscriptional regulation, with the two connected by the function of CSG1. IMPORTANCE In fungi, most metabolic processes are subject to regulation by light. For Trichoderma reesei, light-dependent regulation of cellulase gene expression is specifically shown. Therefore, we intended to unravel the relationship between regulation of enzymes by the carbon source and regulation of enzymes by light. Our two-dimensional analysis included inducing and repressing carbon sources which we used to compare light-specific regulation to dark-specific regulation and to rule out effects specific for a single carbon source. We found close connections with respect to gene regulation as well as significant differences in dealing with carbon in the environment in light and darkness. Moreover, our analyses showed an intricate regulation mechanism for substrate degradation potentially involving surface sensing and provide a basis for knowledge-based screening for strain improvement.
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Bai X, Wang X, Wang S, Ji X, Guan Z, Zhang W, Lu X. Functional Studies of β-Glucosidases of Cytophaga hutchinsonii and Their Effects on Cellulose Degradation. Front Microbiol 2017; 8:140. [PMID: 28210251 PMCID: PMC5288383 DOI: 10.3389/fmicb.2017.00140] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 01/19/2017] [Indexed: 11/17/2022] Open
Abstract
Cytophaga hutchinsonii can rapidly digest crystalline cellulose without free cellulases or cellulosomes. Its cell-contact cellulose degradation mechanism is unknown. In this study, the four β-glucosidase (bgl) genes in C. hutchinsonii were singly and multiply deleted, and the functions of these β-glucosidases in cellobiose and cellulose degradation were investigated. We found that the constitutively expressed BglB played a key role in cellobiose utilization, while BglA which was induced by cellobiose could partially make up for the deletion of bglB. The double deletion mutant ΔbglA/bglB lost the ability to digest cellobiose and could not thrive in cellulose medium, indicating that β-glucosidases were important for cellulose degradation. When cultured in cellulose medium, a small amount of glucose accumulated in the medium in the initial stage of growth for the wild type, while almost no glucose accumulated for ΔbglA/bglB. When supplemented with a small amount of glucose, ΔbglA/bglB started to degrade cellulose and grew in cellulose medium. We inferred that glucose might be essential for initiating cellulose degradation, and with additional glucose, C. hutchinsonii could partially utilize cellulose without β-glucosidases. We also found that there were both cellulose binding cells and free cells when cultured in cellulose. Since direct contact between C. hutchinsonii cells and cellulose is necessary for cellulose degradation, we deduced that the free cells which were convenient to explore new territory in the environment might be fed by the adherent cells which could produce cello-oligosaccharide and glucose into the environment. This study enriched our knowledge of the cellulolytic pathway of C. hutchinsonii.
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Affiliation(s)
- Xinfeng Bai
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Xifeng Wang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Sen Wang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Xiaofei Ji
- Department of Pathogenic Biology, Binzhou Medical University Yantai, China
| | - Zhiwei Guan
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Weican Zhang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
| | - Xuemei Lu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University Jinan, China
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Zhang JG, Li QM, Thakur K, Faisal S, Wei ZJ. A possible water-soluble inducer for synthesis of cellulase in Aspergillus niger. BIORESOURCE TECHNOLOGY 2017; 226:262-266. [PMID: 27993445 DOI: 10.1016/j.biortech.2016.12.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 12/06/2016] [Accepted: 12/07/2016] [Indexed: 06/06/2023]
Abstract
The synthesis of cellulase in filamentous fungi can be triggered by several inducers. In this study, a bamboo-shoot shell pretreated with Pleurotus ostreatus could promote the formation of cellulases in Aspergillus niger. Further identification, including UPLC-TOF-MS, ultrafiltration, and FT-IR, denoted that the soluble inducer was not a traditional disaccharide but a type of modified lignin polymer. This revelation may result in incipient strategies to ameliorate cellulase productivity.
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Affiliation(s)
- Jian-Guo Zhang
- School of Food Science and Engineering, Hefei University of Technology, Hefei 230009, People's Republic of China.
| | - Qi-Meng Li
- College of Environmental Science and Engineering, Anhui Normal University, Wuhu 241002, People's Republic of China.
| | - Kiran Thakur
- School of Food Science and Engineering, Hefei University of Technology, Hefei 230009, People's Republic of China.
| | - Shah Faisal
- School of Food Science and Engineering, Hefei University of Technology, Hefei 230009, People's Republic of China.
| | - Zhao-Jun Wei
- School of Food Science and Engineering, Hefei University of Technology, Hefei 230009, People's Republic of China; Agricultural and Forestry Specialty Food Processing Industry Technological Innovation Strategic Alliance of Anhui Province, Hefei 230009, People's Republic of China.
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A copper-responsive promoter replacement system to investigate gene functions in Trichoderma reesei: a case study in characterizing SAGA genes. Appl Microbiol Biotechnol 2016; 101:2067-2078. [DOI: 10.1007/s00253-016-8036-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/23/2016] [Accepted: 11/26/2016] [Indexed: 10/20/2022]
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Li C, Lin F, Li Y, Wei W, Wang H, Qin L, Zhou Z, Li B, Wu F, Chen Z. A β-glucosidase hyper-production Trichoderma reesei mutant reveals a potential role of cel3D in cellulase production. Microb Cell Fact 2016; 15:151. [PMID: 27585813 PMCID: PMC5009570 DOI: 10.1186/s12934-016-0550-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 08/23/2016] [Indexed: 01/05/2023] Open
Abstract
Background The conversion of cellulose by cellulase to fermentable sugars for biomass-based products such as cellulosic biofuels, biobased fine chemicals and medicines is an environment-friendly and sustainable process, making wastes profitable and bringing economic benefits. Trichoderma reesei is the well-known major workhorse for cellulase production in industry, but the low β-glucosidase activity in T. reesei cellulase leads to inefficiency in biomass degradation and limits its industrial application. Thus, there are ongoing interests in research to develop methods to overcome this insufficiency. Moreover, although β-glucosidases have been demonstrated to influence cellulase production and participate in the regulation of cellulase production, the underlying mechanism remains unclear. Results The T. reesei recombinant strain TRB1 was constructed from T. reesei RUT-C30 by the T-DNA-based mutagenesis. Compared to RUT-C30, TRB1 displays a significant enhancement of extracellular β-glucosidase (BGL1) activity with 17-fold increase, a moderate increase of both the endoglucanase (EG) activity and the exoglucanase (CBH) activity, a minor improvement of the total filter paper activity, and a faster cellulase induction. This superiority of TRB1 over RUT-C30 is independent on carbon sources and improves the saccharification ability of TRB1 cellulase on pretreated corn stover. Furthermore, TRB1 shows better resistance to carbon catabolite repression than RUT-C30. Secretome characterization of TRB1 shows that the amount of CBH, EG and BGL in the supernatant of T. reesei TRB1 was indeed increased along with the enhanced activities of these three enzymes. Surprisingly, qRT-PCR and gene cloning showed that in TRB1 β-glucosidase cel3D was mutated through the random insertion by AMT and was not expressed. Conclusions The T. reesei recombinant strain TRB1 constructed in this study is more desirable for industrial application than the parental strain RUT-C30, showing extracellular β-glucosidase hyper production, high cellulase production within a shorter time and a better resistance to carbon catabolite repression. Disruption of β-glucosidase cel3D in TRB1 was identified, which might contribute to the superiority of TRB1 over RUT-C30 and might play a role in the cellulase production. These results laid a foundation for future investigations to further improve cellulase enzymatic efficiency and reduce cost for T. reesei cellulase production. Electronic supplementary material The online version of this article (doi:10.1186/s12934-016-0550-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chengcheng Li
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Fengming Lin
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China. .,, 37 Jinxianghe Road, Xuanwu District, Nanjing, 210008, Jiangsu Province, China.
| | - Yizhen Li
- State Key Laboratory of Medical Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wei Wei
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Hongyin Wang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Lei Qin
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Nankai District, 300072, People's Republic of China
| | - Zhihua Zhou
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Bingzhi Li
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Nankai District, 300072, People's Republic of China
| | - Fugen Wu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Zhan Chen
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI, 48109, USA
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The Post-genomic Era of Trichoderma reesei: What's Next? Trends Biotechnol 2016; 34:970-982. [PMID: 27394390 DOI: 10.1016/j.tibtech.2016.06.003] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 06/09/2016] [Accepted: 06/13/2016] [Indexed: 11/21/2022]
Abstract
The ascomycete Trichoderma reesei is one of the most well studied cellulolytic microorganisms. This fungus is widely used in the biotechnology industry, mainly in the production of biofuels. Due to its importance, its genome was sequenced in 2008, opening new avenues to study this microorganism. In this 'post-genomic' era, a transcriptomic and proteomic era has emerged. Here, we present an overview of new findings in the gene expression regulation network of T. reesei. We also discuss new rational strategies to obtain mutants that produce hydrolytic enzymes with a higher yield, using metabolic engineering. Finally, we present how synthetic biology strategies can be used to create engineered promoters to efficiently synthesize enzymes for biomass degradation to produce bioethanol.
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Wang M, Lu X. Exploring the Synergy between Cellobiose Dehydrogenase from Phanerochaete chrysosporium and Cellulase from Trichoderma reesei. Front Microbiol 2016; 7:620. [PMID: 27199949 PMCID: PMC4850161 DOI: 10.3389/fmicb.2016.00620] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 04/15/2016] [Indexed: 11/21/2022] Open
Abstract
Recent demands for the production of lignocellulose biofuels boosted research on cellulase. Hydrolysis efficiency and production cost of cellulase are two bottlenecks in “biomass to biofuels” process. The Trichoderma cellulase mixture is one of the most commonly used enzymes for cellulosic hydrolysis. During hydrolytic process cellobiose accumulation causes feedback inhibition against most cellobiohydrolases and endoglucanases. In this study, we demonstrated the synergism effects between cellobiose dehydrogenase (CDH) and cellulase both in vitro and in vivo. The CDH from Phanerochaete chrysosporium was heterologously expressed in Pichia pastoris. Supplementation of the purified CDH in Trichoderma cellulase increased the cellulase activities. Especially β-glucosidase activity was increased by 30–100% varying at different time points. On the other hand, the cdh gene was heterologously expressed in Trichoderma reesei to explore the synergism between CDH and cellulases in vivo. The analyses of gene expression and enzymatic profiles of filter paper activity, carboxymethylcellulase (CMCase) and β-glucosidase show the increased cellulase activity and the enhanced cellulase production in the cdh-expressing strains. The results elucidate a possible mechanism for diminishing the cellobiose inhibition of cellulase by CDH. These findings provide a novel perspective to make more economic enzyme cocktails for commercial application or explore alternative strategies for generating cellulase-producing strains with higher efficiency.
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Affiliation(s)
- Min Wang
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdao, China; Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdao, China
| | - Xuefeng Lu
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdao, China; Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdao, China
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32
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Guo B, Sato N, Biely P, Amano Y, Nozaki K. Comparison of catalytic properties of multiple β-glucosidases of Trichoderma reesei. Appl Microbiol Biotechnol 2016; 100:4959-68. [PMID: 26846743 DOI: 10.1007/s00253-016-7342-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 01/17/2016] [Accepted: 01/19/2016] [Indexed: 11/27/2022]
Abstract
Ten putative Trichoderma reesei β-glucosidase (BGL) isozymes were heterologously expressed in Escherichia coli and Aspergillus oryzae and purified to homogeneity. Catalytic properties of nine enzymes which showed hydrolytic activity on cellobiose and p-nitrophenyl-β-D-glucopyranoside (pNPG) were investigated. Three BGLs, encoded by the genes cel3A, cel3B, and cel3E, contained a predicted signal peptide, showed higher hydrolytic activity on cello-oligosaccharides than on pNPG, and preferred longer oligosaccharides. Another three putative extracellular BGLs, Cel3B, Cel3F, and Cel3G, and two intracellular enzymes, Cel3C and Cel3D, exhibited preference for pNPG. Intracellular Cel1A showed the highest affinity for cellobiose as a typical cellobiase. Four BGLs, Cel3A, Cel3B, Cel3E, Cel1A, that showed high activity against cello-oligosaccharides were capable of catalyzing transglycosylation reactions from cellobiose, leading to formation of cellotriose and isomeric glucobioses. While Cel3A, Cel3B, and Cel3E synthesized mainly gentiobiose, glycosyl transfer reactions of Cel1A led mainly to sophorose and laminaribiose. Conversion of cellobiose to sophorose by Cel1A reached about 3.6 and 10 % at 1 and 10 % cellobiose concentration, respectively. The formation and persistence of individual cellobiose isomers in incubation mixtures of four BGLs (Cel3A, Cel3B, Cel3E, and Cel1A) with cellobiose correlated well with the k cat values for isomeric glucobioses. Cel1A also showed the lowest sensitivity to inhibition by glucose. Based on all studied catalytic properties, Cel1A appears to be unambiguously the best candidate for site-directed mutations or directed evolution toward improvement of activity, thermostability, and, eventually, efficiency of sophorose synthesis.
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Affiliation(s)
- Boyang Guo
- Department of Bioscience and Textile Technology, Interdisciplinary Graduate School of Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano, 380-8553, Japan
| | - Nobuaki Sato
- Department of Bioscience and Textile Technology, Interdisciplinary Graduate School of Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano, 380-8553, Japan
| | - Peter Biely
- Institute of Chemistry, Slovak Academy of Sciences, 845 38, Bratislava, Slovakia
| | - Yoshihiko Amano
- Department of Bioscience and Textile Technology, Interdisciplinary Graduate School of Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano, 380-8553, Japan
| | - Kouichi Nozaki
- Department of Bioscience and Textile Technology, Interdisciplinary Graduate School of Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano, 380-8553, Japan.
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An Outer Membrane Protein Involved in the Uptake of Glucose Is Essential for Cytophaga hutchinsonii Cellulose Utilization. Appl Environ Microbiol 2016; 82:1933-1944. [PMID: 26773084 DOI: 10.1128/aem.03939-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 01/08/2016] [Indexed: 11/20/2022] Open
Abstract
Cytophaga hutchinsonii specializes in cellulose digestion by employing a collection of novel cell-associated proteins. Here, we identified a novel gene locus, CHU_1276, that is essential for C. hutchinsonii cellulose utilization. Disruption of CHU_1276 in C. hutchinsonii resulted in complete deficiency in cellulose degradation, as well as compromised assimilation of cellobiose or glucose at a low concentration. Further analysis showed that CHU_1276 was an outer membrane protein that could be induced by cellulose and low concentrations of glucose. Transcriptional profiling revealed that CHU_1276 exerted a profound effect on the genome-wide response to both glucose and Avicel and that the mutant lacking CHU_1276 displayed expression profiles very different from those of the wild-type strain under different culture conditions. Specifically, comparison of their transcriptional responses to cellulose led to the identification of a gene set potentially regulated by CHU_1276. These results suggest that CHU_1276 plays an essential role in cellulose utilization, probably by coordinating the extracellular hydrolysis of cellulose substrate with the intracellular uptake of the hydrolysis product in C. hutchinsonii.
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Druzhinina IS, Kubicek CP. Familiar Stranger: Ecological Genomics of the Model Saprotroph and Industrial Enzyme Producer Trichoderma reesei Breaks the Stereotypes. ADVANCES IN APPLIED MICROBIOLOGY 2016; 95:69-147. [PMID: 27261782 DOI: 10.1016/bs.aambs.2016.02.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The filamentous fungus Trichoderma reesei (Hypocreales, Ascomycota) has properties of an efficient cell factory for protein production that is exploited by the enzyme industry, particularly with respect to cellulase and hemicellulase formation. Under conditions of industrial fermentations it yields more than 100g secreted protein L(-1). Consequently, T. reesei has been intensively studied in the 20th century. Most of these investigations focused on the biochemical characteristics of its cellulases and hemicellulases, on the improvement of their properties by protein engineering, and on enhanced enzyme production by recombinant strategies. However, as the fungus is rare in nature, its ecology remained unknown. The breakthrough in the understanding of the fundamental biology of T. reesei only happened during 2000s-2010s. In this review, we compile the current knowledge on T. reesei ecology, physiology, and genomics to present a holistic view on the natural behavior of the organism. This is not only critical for science-driven further improvement of the biotechnological applications of this fungus, but also renders T. reesei as an attractive model of filamentous fungi with superior saprotrophic abilities.
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Affiliation(s)
- I S Druzhinina
- Institute of Chemical Engineering, TU Wien, Vienna, Austria
| | - C P Kubicek
- Institute of Chemical Engineering, TU Wien, Vienna, Austria
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Shida Y, Yamaguchi K, Nitta M, Nakamura A, Takahashi M, Kidokoro SI, Mori K, Tashiro K, Kuhara S, Matsuzawa T, Yaoi K, Sakamoto Y, Tanaka N, Morikawa Y, Ogasawara W. The impact of a single-nucleotide mutation of bgl2 on cellulase induction in a Trichoderma reesei mutant. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:230. [PMID: 26719764 PMCID: PMC4696228 DOI: 10.1186/s13068-015-0420-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 12/15/2015] [Indexed: 05/10/2023]
Abstract
BACKGROUND The filamentous fungus Trichoderma reesei (anamorph of Hypocrea jecorina) produces increased cellulase expression when grown on cellulose or its derivatives as a sole carbon source. It has been believed that β-glucosidases of T. reesei not only metabolize cellobiose but also contribute in the production of inducers of cellulase gene expression by their transglycosylation activity. The cellulase hyper-producing mutant PC-3-7 developed in Japan has enhanced cellulase production ability when cellobiose is used as the inducer. The comparative genomics analysis of PC-3-7 and its parent revealed a single-nucleotide mutation within the bgl2 gene encoding intracellular β-glucosidase II (BGLII/Cel1a), giving rise to an amino acid substitution in PC-3-7, which could potentially account for the enhanced cellulase expression when these strains are cultivated on cellulose and cellobiose. RESULTS To analyze the effects of the BGLII mutation in cellulase induction, we constructed both a bgl2 revertant and a disruptant. Enzymatic analysis of the transformant lysates showed that the strain expressing mutant BGLII exhibited weakened cellobiose hydrolytic activity, but produced some transglycosylation products, suggesting that the SNP in bgl2 strongly diminished cellobiase activity, but did not result in complete loss of function of BGLII. The analysis of the recombinant BGLII revealed that transglycosylation products might be oligosaccharides, composed probably of glucose linked β-1,4, β-1,3, or a mixture of both. PC-3-7 revertants of bgl2 exhibited reduced expression and inducibility of cellulase during growth on cellulose and cellobiose substrates. Furthermore, the effect of this bgl2 mutation was reproduced in the common strain QM9414 in which the transformants showed cellulase production comparable to that of PC-3-7. CONCLUSION We conclude that BGLII plays an important role in cellulase induction in T. reesei and that the bgl2 mutation in PC-3-7 brought about enhanced cellulase expression on cellobiose. The results of the investigation using PC-3-7 suggested that other mutation(s) in PC-3-7 could also contribute to cellulase induction. Further investigation is essential to unravel the mechanism responsible for cellulase induction in T. reesei.
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Affiliation(s)
- Yosuke Shida
- />Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 Japan
| | - Kaori Yamaguchi
- />Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 Japan
| | - Mikiko Nitta
- />Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 Japan
- />Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 Japan
| | - Ayana Nakamura
- />Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 Japan
| | - Machiko Takahashi
- />Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 Japan
| | - Shun-ichi Kidokoro
- />Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 Japan
| | - Kazuki Mori
- />Department of Genetic Resources Technology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka, 812-8581 Japan
| | - Kosuke Tashiro
- />Department of Genetic Resources Technology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka, 812-8581 Japan
| | - Satoru Kuhara
- />Department of Genetic Resources Technology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka, 812-8581 Japan
| | - Tomohiko Matsuzawa
- />Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566 Japan
| | - Katsuro Yaoi
- />Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566 Japan
| | - Yasumitsu Sakamoto
- />School of Pharmacy, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba, Iwate 028-3694 Japan
| | - Nobutada Tanaka
- />School of Pharmacy, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8555 Japan
| | - Yasushi Morikawa
- />Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 Japan
| | - Wataru Ogasawara
- />Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 Japan
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Ouedraogo JP, Arentshorst M, Nikolaev I, Barends S, Ram AFJ. I-SceI-mediated double-strand DNA breaks stimulate efficient gene targeting in the industrial fungus Trichoderma reesei. Appl Microbiol Biotechnol 2015; 99:10083-95. [PMID: 26272087 PMCID: PMC4643118 DOI: 10.1007/s00253-015-6829-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 07/03/2015] [Accepted: 07/07/2015] [Indexed: 01/24/2023]
Abstract
Targeted integration of expression cassettes for enzyme production in industrial microorganisms is desirable especially when enzyme variants are screened for improved enzymatic properties. However, currently used methods for targeted integration are inefficient and result in low transformation frequencies. In this study, we expressed the Saccharomyces cerevisiae I-SceI meganuclease to generate double-strand breaks at a defined locus in the Trichoderma reesei genome. We showed that the double-strand DNA breaks mediated by I-SceI can be efficiently repaired when an exogenous DNA cassette flanked by regions homologous to the I-SceI landing locus was added during transformation. Transformation efficiencies increased approximately sixfold compared to control transformation. Analysis of the transformants obtained via I-SceI-mediated gene targeting showed that about two thirds of the transformants resulted from a homologous recombination event at the predetermined locus. Counter selection of the transformants for the loss of the pyrG marker upon integration of the DNA cassette showed that almost all of the clones contained the cassette at the predetermined locus. Analysis of independently obtained transformants using targeted integration of a glucoamylase expression cassette demonstrated that glucoamylase production among the transformants was high and showing limited variation. In conclusion, the gene targeting system developed in this study significantly increases transformation efficiency as well as homologous recombination efficiency and omits the use of Δku70 strains. It is also suitable for high-throughput screening of enzyme variants or gene libraries in T. reesei.
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Affiliation(s)
- Jean Paul Ouedraogo
- Molecular Microbiology and Biotechnology, Institute of Biology Leiden, Kluyver Centre for Genomics of Industrial Fermentation, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Mark Arentshorst
- Molecular Microbiology and Biotechnology, Institute of Biology Leiden, Kluyver Centre for Genomics of Industrial Fermentation, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Igor Nikolaev
- Dupont Industrial Biosciences, Archimedesweg 30, 2333 CN, Leiden, The Netherlands
| | - Sharief Barends
- Dupont Industrial Biosciences, Archimedesweg 30, 2333 CN, Leiden, The Netherlands
| | - Arthur F J Ram
- Molecular Microbiology and Biotechnology, Institute of Biology Leiden, Kluyver Centre for Genomics of Industrial Fermentation, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.
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