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Mandal M, Roy A, Das S, Rakwal R, Agrawal GK, Singh P, Awasthi A, Sarkar A. Food waste-based bio-fertilizers production by bio-based fermenters and their potential impact on the environment. CHEMOSPHERE 2024; 353:141539. [PMID: 38417498 DOI: 10.1016/j.chemosphere.2024.141539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 02/01/2024] [Accepted: 02/23/2024] [Indexed: 03/01/2024]
Abstract
Increasing food waste is creating a global waste (and management) crisis. Globally, ∼1.6 billion tons of food is wasted annually, worth ∼$1.2 trillion. By reducing this waste or by turning it into valuable products, numerous economic advantages can be realized, including improved food security, lower production costs, biodegradable products, environmental sustainability, and cleaner solutions to the growing world's waste and garbage management. The appropriate handling of these detrimental materials can significantly reduce the risks to human health. Food waste is available in biodegradable forms and, with the potential to speed up microbial metabolism effectively, has immense potential in improving bio-based fertilizer generation. Synthetic inorganic fertilizers severely affect human health, the environment, and soil fertility, thus requiring immediate consideration. To address these problems, agricultural farming is moving towards manufacturing bio-based fertilizers via utilizing natural bioresources. Food waste-based bio-fertilizers could help increase yields, nutrients, and organic matter and mitigate synthetic fertilizers' adverse effects. These are presented and discussed in the review.
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Affiliation(s)
- Mamun Mandal
- Laboratory of Applied Stress Biology, Department of Botany, University of Gour Banga, Malda, 732 103, West Bengal, India
| | - Anamika Roy
- Laboratory of Applied Stress Biology, Department of Botany, University of Gour Banga, Malda, 732 103, West Bengal, India
| | - Sujit Das
- Laboratory of Applied Stress Biology, Department of Botany, University of Gour Banga, Malda, 732 103, West Bengal, India
| | - Randeep Rakwal
- Institute of Health and Sport Sciences, Global Sport Innovation Bldg., Room 403, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8574, Japan; GRADE Academy (Pvt.) Ltd., Birgunj, Nepal
| | | | - Pardeep Singh
- Department of Environmental Studies, PGDAV College, University of Delhi, New Delhi, 110065, India
| | - Amit Awasthi
- Department of Applied Sciences, University of Petroleum and Energy Studies, Dehradun, India
| | - Abhijit Sarkar
- Laboratory of Applied Stress Biology, Department of Botany, University of Gour Banga, Malda, 732 103, West Bengal, India.
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Yue X, Ren X, Fu J, Wei N, Altomare C, Haidukowski M, Logrieco AF, Zhang Q, Li P. Characterization and mechanism of aflatoxin degradation by a novel strain of Trichoderma reesei CGMCC3.5218. Front Microbiol 2022; 13:1003039. [PMID: 36312918 PMCID: PMC9611206 DOI: 10.3389/fmicb.2022.1003039] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 09/21/2022] [Indexed: 11/27/2022] Open
Abstract
Aflatoxins, which are produced mainly by Aspergillus flavus and A. parasiticus, are recognized as the most toxic mycotoxins, which are strongly carcinogenic and pose a serious threat to human and animal health. Therefore, strategies to degrade or eliminate aflatoxins in agro-products are urgently needed. We investigated 65 Trichoderma isolates belonging to 23 species for their aflatoxin B1 (AFB1)-degrading capabilities. Trichoderma reesei CGMCC3.5218 had the best performance, and degraded 100% of 50 ng/kg AFB1 within 3 days and 87.6% of 10 μg/kg AFB1 within 5 days in a liquid-medium system. CGMCC3.5218 degraded more than 85.0% of total aflatoxins (aflatoxin B1, B2, G1, and G2) at 108.2–2323.5 ng/kg in artificially and naturally contaminated peanut, maize, and feed within 7 days. Box–Behnken design and response surface methodology showed that the optimal degradation conditions for CGMCC3.5218 were pH 6.7 and 31.3°C for 5.1 days in liquid medium. Possible functional detoxification components were analyzed, indicating that the culture supernatant of CGMCC3.5218 could efficiently degrade AFB1 (500 ng/kg) with a ratio of 91.8%, compared with 19.5 and 8.9% by intracellular components and mycelial adsorption, respectively. The aflatoxin-degrading activity of the fermentation supernatant was sensitive to proteinase K and proteinase K plus sodium dodecyl sulfonate, but was stable at high temperatures, suggesting that thermostable enzymes or proteins in the fermentation supernatant played a major role in AFB1 degradation. Furthermore, toxicological experiments by a micronucleus assay in mouse bone marrow erythrocytes and by intraperitoneal injection and skin irritation tests in mice proved that the degradation products by CGMCC3.5218 were nontoxic. To the best of our knowledge, this is the first comprehensive study on Trichoderma aflatoxin detoxification, and the candidate strain T. reesei CGMCC3.5218 has high efficient and environment-friendly characteristics, and qualifies as a potential biological detoxifier for application in aflatoxin removal from contaminated feeds.
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Affiliation(s)
- Xiaofeng Yue
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan, China
| | - Xianfeng Ren
- Institute of Quality Standard and Testing Technology for Agro-products, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Jiayun Fu
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan, China
| | - Na Wei
- Institutions of Agricultural Product Quality Standard and Testing Research, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, China
| | - Claudio Altomare
- Institute of Sciences of Food Production, National Research Council, Bari, Italy
- *Correspondence: Claudio Altomare,
| | - Miriam Haidukowski
- Institute of Sciences of Food Production, National Research Council, Bari, Italy
| | - Antonio F. Logrieco
- Institute of Sciences of Food Production, National Research Council, Bari, Italy
| | - Qi Zhang
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan, China
- Hubei Hongshan Lab, Wuhan, China
- Qi Zhang,
| | - Peiwu Li
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan, China
- Peiwu Li,
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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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Wang Y, Liu R, Liu H, Li X, Shen L, Zhang W, Song X, Liu W, Liu X, Zhong Y. Development of a powerful synthetic hybrid promoter to improve the cellulase system of Trichoderma reesei for efficient saccharification of corncob residues. Microb Cell Fact 2022; 21:5. [PMID: 34983541 PMCID: PMC8725555 DOI: 10.1186/s12934-021-01727-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 12/17/2021] [Indexed: 02/07/2023] Open
Abstract
Background The filamentous fungus Trichoderma reesei is a widely used workhorse for cellulase production in industry due to its prominent secretion capacity of extracellular cellulolytic enzymes. However, some key components are not always sufficient in this cellulase cocktail, making the conversion of cellulose-based biomass costly on the industrial scale. Development of strong and efficient promoters would enable cellulase cocktail to be optimized for bioconversion of biomass. Results In this study, a synthetic hybrid promoter was constructed and applied to optimize the cellulolytic system of T. reesei for efficient saccharification towards corncob residues. Firstly, a series of 5’ truncated promoters in different lengths were established based on the strong constitutive promoter Pcdna1. The strongest promoter amongst them was Pcdna1-3 (− 640 to − 1 bp upstream of the translation initiation codon ATG), exhibiting a 1.4-fold higher activity than that of the native cdna1 promoter. Meanwhile, the activation region (− 821 to − 622 bp upstream of the translation initiation codon ATG and devoid of the Cre1-binding sites) of the strong inducible promoter Pcbh1 was cloned and identified to be an amplifier in initiating gene expression. Finally, this activation region was fused to the strongest promoter Pcdna1-3, generating the novel synthetic hybrid promoter Pcc. This engineered promoter Pcc drove strong gene expression by displaying 1.6- and 1.8-fold stronger fluorescence intensity than Pcbh1 and Pcdna1 under the inducible condition using egfp as the reporter gene, respectively. Furthermore, Pcc was applied to overexpress the Aspergillus niger β-glucosidase BGLA coding gene bglA and the native endoglucanase EG2 coding gene eg2, achieving 43.5-fold BGL activity and 1.2-fold EG activity increase, respectively. Ultimately, to overcome the defects of the native cellulase system in T. reesei, the bglA and eg2 were co-overexpressed under the control of Pcc promoter. The bglA-eg2 double expression strain QPEB70 exhibited a 178% increase in total cellulase activity, whose cellulase system displayed 2.3- and 2.4-fold higher saccharification efficiency towards acid-pretreated and delignified corncob residues than the parental strain, respectively. Conclusions The synthetic hybrid promoter Pcc was generated and employed to improve the cellulase system of T. reesei by expressing specific components. Therefore, construction of synthetic hybrid promoters would allow particular cellulase genes to be expressed at desired levels, which is a viable strategy to optimize the cellulolytic enzyme system for efficient biomass bioconversion. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-021-01727-8.
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Affiliation(s)
- Yifan Wang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Ruiyan Liu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Hong Liu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Xihai Li
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Linjing Shen
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Weican Zhang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Xin Song
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Xiangmei Liu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China.
| | - Yaohua Zhong
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China.
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Sukumaran RK, Christopher M, Kooloth-Valappil P, Sreeja-Raju A, Mathew RM, Sankar M, Puthiyamadam A, Adarsh VP, Aswathi A, Rebinro V, Abraham A, Pandey A. Addressing challenges in production of cellulases for biomass hydrolysis: Targeted interventions into the genetics of cellulase producing fungi. BIORESOURCE TECHNOLOGY 2021; 329:124746. [PMID: 33610429 DOI: 10.1016/j.biortech.2021.124746] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 01/12/2021] [Accepted: 01/15/2021] [Indexed: 06/12/2023]
Abstract
Lignocellulosic materials are the favoured feedstock for biorefineries due to their abundant availability and non-completion with food. Biobased technologies for refining these materials are limited mainly by the cost of biomass hydrolyzing enzymes, typically sourced from filamentous fungi. Therefore, considerable efforts have been directed at improving the quantity and quality of secreted lignocellulose degrading enzymes from fungi in order to attain overall economic viability. Process improvements and media engineering probably have reached their thresholds and further production enhancements require modifying the fungal metabolism to improve production and secretion of these enzymes. This review focusses on the types and mechanisms of action of known fungal biomass degrading enzymes, our current understanding of the genetic control exerted on their expression, and possible routes for intervention, especially on modulating catabolite repression, transcriptional regulators, signal transduction, secretion pathways etc., in order to improve enzyme productivity, activity and stability.
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Affiliation(s)
- Rajeev K Sukumaran
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India.
| | - Meera Christopher
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Prajeesh Kooloth-Valappil
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - AthiraRaj Sreeja-Raju
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Reshma M Mathew
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Meena Sankar
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Anoop Puthiyamadam
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India
| | - Velayudhanpillai-Prasannakumari Adarsh
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India
| | - Aswathi Aswathi
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India
| | - Valan Rebinro
- Centre for Biofuels, Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India
| | - Amith Abraham
- Department of Chemical Engineering, Hanyang University, Seoul, Republic of Korea
| | - Ashok Pandey
- Centre for Innovation and Translational Research, CSIR-Indian Institute of Toxicology Research, Lucknow, India
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Chysirichote T, Mapisansup W, Aroonsong S. Estimation of glucosamine in biomass of Trichoderma reesei cultivated on lignocellulosic substrates. J Basic Microbiol 2021; 61:305-314. [PMID: 33605476 DOI: 10.1002/jobm.202000609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 01/29/2021] [Accepted: 02/02/2021] [Indexed: 11/09/2022]
Abstract
Effects of the compositions of lignocellulosic substrate including hemicellulose, cellulose, lignin, and protein on the glucosamine content in biomass of Trichoderma reesei TISTR3080 were studied. A synthetic solid surface media containing different ratios of xylan (hemicellulose), carboxymethyl cellulose (cellulose), lignin, and various concentrations of yeast extract (source of protein) were used to cultivated T. reesei. Regression analysis identified significant individual and interaction factors that affected glucosamine quantity in T. reesei biomass. A regression model was developed to estimate the glucosamine content in biomass of T. reesei from the compositions of the lignocellulosic substrate. An acceptable error (not more than 10%) of the regression model was obtained from validation with the experimental results of glucosamine content in biomass of T. reesei cultivated on lignocellulosic solid surface media made from copra waste and banana peel.
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Affiliation(s)
- Teerin Chysirichote
- Department of Food Engineering, School of Engineering, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand
| | - Waraporn Mapisansup
- Department of Food Engineering, School of Engineering, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand
| | - Soysrung Aroonsong
- Department of Food Engineering, School of Engineering, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand
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Synergistic Action of a Lytic Polysaccharide Monooxygenase and a Cellobiohydrolase from Penicillium funiculosum in Cellulose Saccharification under High-Level Substrate Loading. Appl Environ Microbiol 2020; 86:AEM.01769-20. [PMID: 32978122 DOI: 10.1128/aem.01769-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/15/2020] [Indexed: 12/25/2022] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are crucial industrial enzymes required in the biorefinery industry as well as in the natural carbon cycle. These enzymes, known to catalyze the oxidative cleavage of glycosidic bonds, are produced by numerous bacterial and fungal species to assist in the degradation of cellulosic biomass. In this study, we annotated and performed structural analysis of an uncharacterized LPMO from Penicillium funiculosum (PfLPMO9) based on computational methods in an attempt to understand the behavior of this enzyme in biomass degradation. PfLPMO9 exhibited 75% and 36% sequence identities with LPMOs from Thermoascus aurantiacus (TaLPMO9A) and Lentinus similis (LsLPMO9A), respectively. Furthermore, multiple fungal genetic manipulation tools were employed to simultaneously overexpress LPMO and cellobiohydrolase I (CBH1) in a catabolite-derepressed strain of Penicillium funiculosum, PfMig188 (an engineered variant of P. funiculosum), to improve its saccharification performance toward acid-pretreated wheat straw (PWS) at 20% substrate loading. The resulting transformants showed improved LPMO and CBH1 expression at both the transcriptional and translational levels, with ∼200% and ∼66% increases in ascorbate-induced LPMO and Avicelase activities, respectively. While the secretome of PfMig88 overexpressing LPMO or CBH1 increased the saccharification of PWS by 6% or 13%, respectively, over the secretome of PfMig188 at the same protein concentration, the simultaneous overexpression of these two genes led to a 20% increase in saccharification efficiency over that observed with PfMig188, which accounted for 82% saccharification of PWS under 20% substrate loading.IMPORTANCE The enzymatic hydrolysis of cellulosic biomass by cellulases continues to be a significant bottleneck in the development of second-generation biobased industries. While increasing efforts are being made to obtain indigenous cellulases for biomass hydrolysis, the high production cost of this enzyme remains a crucial challenge affecting its wide availability for the efficient utilization of cellulosic materials. This is because it is challenging to obtain an enzymatic cocktail with balanced activity from a single host. This report describes the annotation and structural analysis of an uncharacterized lytic polysaccharide monooxygenase (LPMO) gene in Penicillium funiculosum and its impact on biomass deconstruction upon overexpression in a catabolite-derepressed strain of P. funiculosum Cellobiohydrolase I (CBH1), which is the most important enzyme produced by many cellulolytic fungi for the saccharification of crystalline cellulose, was further overexpressed simultaneously with LPMO. The resulting secretome was analyzed for enhanced LPMO and exocellulase activities and the corresponding improvement in saccharification performance (by ∼20%) under high-level substrate loading using a minimal amount of protein.
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Jiang X, Du J, He R, Zhang Z, Qi F, Huang J, Qin L. Improved Production of Majority Cellulases in Trichoderma reesei by Integration of cbh1 Gene From Chaetomium thermophilum. Front Microbiol 2020; 11:1633. [PMID: 32765463 PMCID: PMC7381231 DOI: 10.3389/fmicb.2020.01633] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 06/23/2020] [Indexed: 11/17/2022] Open
Abstract
Lignocellulose is an abundant waste resource and has been considered as a promising material for production of biofuels or other valuable bio-products. Currently, one of the major bottlenecks in the economic utilization of lignocellulosic materials is the cost-efficiency of converting lignocellulose into soluble sugars for fermentation. One way to address this problem is to seek superior lignocellulose degradation enzymes or further improve current production yields of lignocellulases. In the present study, the lignocellulose degradation capacity of a thermophilic fungus Chaetomium thermophilum was firstly evaluated and compared to that of the biotechnological workhorse Trichoderma reesei. The data demonstrated that compared to T. reesei, C. thermophilum displayed substantially higher cellulose-utilizing efficiency with relatively lower production of cellulases, indicating that better cellulases might exist in C. thermophilum. Comparison of the protein secretome between C. thermophilum and T. reesei showed that the secreted protein categories were quite different in these two species. In addition, to prove that cellulases in C. thermophilum had better enzymatic properties, the major cellulase cellobiohydrolase I (CBH1) from C. thermophilum and T. reesei were firstly characterized, respectively. The data showed that the specific activity of C. thermophilum CBH1 was about 4.5-fold higher than T. reesei CBH1 in a wide range of temperatures and pH. To explore whether increasing CBH1 activity in T. reesei could contribute to improving the overall cellulose-utilizing efficiency of T. reesei, T. reesei cbh1 gene was replaced with C. thermophilum cbh1 gene by integration of C. thermophilum cbh1 gene into T. reesei cbh1 gene locus. The data surprisingly showed that this gene replacement not only increased the cellobiohydrolase activities by around 4.1-fold, but also resulted in stronger induction of other cellulases genes, which caused the filter paper activities, Azo-CMC activities and β-glucosidase activities increased by about 2.2, 1.9, and 2.3-fold, respectively. The study here not only provided new resources of superior cellulases genes and new strategy to improve the cellulase production in T. reesei, but also contribute to opening the path for fundamental research on C. thermophilum.
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Affiliation(s)
- Xianzhang Jiang
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Jiawen Du
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Ruonan He
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Zhengying Zhang
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Feng Qi
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Jianzhong Huang
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Lina Qin
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China.,Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, College of Life Sciences, Fujian Normal University, Fuzhou, China
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Cai L, Xu S, Lu T, Lin D, Yao S. Salt-tolerant mechanism of marine Aspergillus niger cellulase cocktail and improvement of its activity. Chin J Chem Eng 2020. [DOI: 10.1016/j.cjche.2019.11.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Srivastava N, Rathour R, Jha S, Pandey K, Srivastava M, Thakur VK, Sengar RS, Gupta VK, Mazumder PB, Khan AF, Mishra PK. Microbial Beta Glucosidase Enzymes: Recent Advances in Biomass Conversation for Biofuels Application. Biomolecules 2019; 9:E220. [PMID: 31174354 PMCID: PMC6627771 DOI: 10.3390/biom9060220] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/28/2019] [Accepted: 05/28/2019] [Indexed: 01/10/2023] Open
Abstract
The biomass to biofuels production process is green, sustainable, and an advanced technique to resolve the current environmental issues generated from fossil fuels. The production of biofuels from biomass is an enzyme mediated process, wherein β-glucosidase (BGL) enzymes play a key role in biomass hydrolysis by producing monomeric sugars from cellulose-based oligosaccharides. However, the production and availability of these enzymes realize their major role to increase the overall production cost of biomass to biofuels production technology. Therefore, the present review is focused on evaluating the production and efficiency of β-glucosidase enzymes in the bioconversion of cellulosic biomass for biofuel production at an industrial scale, providing its mechanism and classification. The application of BGL enzymes in the biomass conversion process has been discussed along with the recent developments and existing issues. Moreover, the production and development of microbial BGL enzymes have been explained in detail, along with the recent advancements made in the field. Finally, current hurdles and future suggestions have been provided for the future developments. This review is likely to set a benchmark in the area of cost effective BGL enzyme production, specifically in the biorefinery area.
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Affiliation(s)
- Neha Srivastava
- Department of Chemical Engineering and Technology, IIT (BHU), Varanasi 221005, India.
| | - Rishabh Rathour
- Department of Bioengineering, Integral University, Lucknow 226026, India.
| | - Sonam Jha
- Department of Botany, Banaras Hindu University, Varanasi 221005, India.
| | - Karan Pandey
- Department of Chemical Engineering and Technology, IIT (BHU), Varanasi 221005, India.
| | - Manish Srivastava
- Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India.
| | - Vijay Kumar Thakur
- Enhanced Composites and Structures Center, School of Aerospace, Transport and Manufacturing, Cranfield University, Bedfordshire MK43 0AL, UK.
| | - Rakesh Singh Sengar
- Department of Agriculture Biotechnology, College of Agriculture, Sardar Vallabhbhai Patel, University of Agriculture and Technology, Meerut 250110, U.P., India.
| | - Vijai K Gupta
- Department of Chemistry and Biotechnology, ERA Chair of Green Chemistry, Tallinn University of Technology, 12618 Tallinn, Estonia.
| | | | - Ahamad Faiz Khan
- Department of Bioengineering, Integral University, Lucknow 226026, India.
| | - Pradeep Kumar Mishra
- Department of Chemical Engineering and Technology, IIT (BHU), Varanasi 221005, India.
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12
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Lignocellulolytic characterization and comparative secretome analysis of a Trichoderma erinaceum strain isolated from decaying sugarcane straw. Fungal Biol 2019; 123:330-340. [PMID: 30928041 DOI: 10.1016/j.funbio.2019.01.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 01/18/2019] [Accepted: 01/24/2019] [Indexed: 11/21/2022]
Abstract
The fungus Trichoderma reesei is employed in the production of most enzyme cocktails used by the lignocellulosic biofuels industry today. Despite significant improvements, the cost of the required enzyme preparations remains high, representing a major obstacle for the industrial production of these alternative fuels. In this study, a new Trichoderma erinaceum strain was isolated from decaying sugarcane straw. The enzyme cocktail secreted by the new isolate during growth in pretreated sugarcane straw-containing medium presented higher specific activities of β-glucosidase, endoxylanase, β-xylosidase and α-galactosidase than the cocktail of a wild T. reesei strain and yielded more glucose in the hydrolysis of pretreated sugarcane straw. A proteomic analysis of the two strains' secretomes identified a total of 86 proteins, of which 48 were exclusive to T. erinaceum, 35 were exclusive to T. reesei and only 3 were common to both strains. The secretome of T. erinaceum also displayed a higher number of carbohydrate-active enzymes than that of T. reesei (37 and 27 enzymes, respectively). Altogether, these results reveal the significant potential of the T. erinaceum species for the production of lignocellulases, both as a possible source of enzymes for the supplementation of industrial cocktails and as a candidate chassis for enzyme production.
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13
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Wei H, Wang W, Alper HS, Xu Q, Knoshaug EP, Van Wychen S, Lin CY, Luo Y, Decker SR, Himmel ME, Zhang M. Ameliorating the Metabolic Burden of the Co-expression of Secreted Fungal Cellulases in a High Lipid-Accumulating Yarrowia lipolytica Strain by Medium C/N Ratio and a Chemical Chaperone. Front Microbiol 2019; 9:3276. [PMID: 30687267 PMCID: PMC6333634 DOI: 10.3389/fmicb.2018.03276] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 12/17/2018] [Indexed: 12/19/2022] Open
Abstract
Yarrowia lipolytica, known to accumulate lipids intracellularly, lacks the cellulolytic enzymes needed to break down solid biomass directly. This study aimed to evaluate the potential metabolic burden of expressing core cellulolytic enzymes in an engineered high lipid-accumulating strain of Y. lipolytica. Three fungal cellulases, Talaromyces emersonii-Trichoderma reesei chimeric cellobiohydrolase I (chimeric-CBH I), T. reesei cellobiohydrolase II (CBH II), and T. reesei endoglucanase II (EG II) were expressed using three constitutive strong promoters as a single integrative expression block in a recently engineered lipid hyper-accumulating strain of Y. lipolytica (HA1). In yeast extract-peptone-dextrose (YPD) medium, the resulting cellulase co-expressing transformant YL165-1 had the chimeric-CBH I, CBH II, and EG II secretion titers being 26, 17, and 132 mg L-1, respectively. Cellulase co-expression in YL165-1 in culture media with a moderate C/N ratio of ∼4.5 unexpectedly resulted in a nearly two-fold reduction in cellular lipid accumulation compared to the parental control strain, a sign of cellular metabolic drain. Such metabolic drain was ameliorated when grown in media with a high C/N ratio of 59 having a higher glucose utilization rate that led to approximately twofold more cell mass and threefold more lipid production per liter culture compared to parental control strain, suggesting cross-talk between cellulase and lipid production, both of which involve the endoplasmic reticulum (ER). Most importantly, we found that the chemical chaperone, trimethylamine N-oxide dihydride increased glucose utilization, cell mass and total lipid titer in the transformants, suggesting further amelioration of the metabolic drain. This is the first study examining lipid production in cellulase-expressing Y. lipolytica strains under various C/N ratio media and with a chemical chaperone highlighting the metabolic complexity for developing robust, cellulolytic and lipogenic yeast strains.
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Affiliation(s)
- Hui Wei
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Wei Wang
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Hal S Alper
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, United States
| | - Qi Xu
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Eric P Knoshaug
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Stefanie Van Wychen
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States.,National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Chien-Yuan Lin
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Yonghua Luo
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Stephen R Decker
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Michael E Himmel
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Min Zhang
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States.,National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, United States
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14
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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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15
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Liu G, Qu Y. Engineering of filamentous fungi for efficient conversion of lignocellulose: Tools, recent advances and prospects. Biotechnol Adv 2018; 37:519-529. [PMID: 30576717 DOI: 10.1016/j.biotechadv.2018.12.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 12/13/2018] [Accepted: 12/14/2018] [Indexed: 01/17/2023]
Abstract
Filamentous fungi, as the main producers of lignocellulolytic enzymes in industry, need to be engineered to improve the economy of large-scale lignocellulose conversion. Investigation of the cellular processes involved in lignocellulolytic enzyme production, as well as optimization of enzyme mixtures for higher hydrolysis efficiency, have provided effective targets for the engineering of lignocellulolytic fungi. Recently, the development of efficient genetic manipulation systems in several lignocellulolytic fungi opens up the possibility of systems engineering of these strains. Here, we review the recent progresses made in the engineering of lignocellulolytic fungi and highlight the research gaps in this area.
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Affiliation(s)
- Guodong Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China; Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China; National Glycoengineering Research Center, Shandong University, Qingdao 266237, China.
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16
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Role of the antioxidant defense system during the production of lignocellulolytic enzymes by fungi. Int Microbiol 2018; 22:255-264. [PMID: 30810986 DOI: 10.1007/s10123-018-00045-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 11/06/2018] [Accepted: 11/07/2018] [Indexed: 12/31/2022]
Abstract
Fungi are used for the production of several compounds and the efficiency of biotechnological processes is directly related to the metabolic activity of these microorganisms. The reactions catalyzed by lignocellulolytic enzymes are oxidative and generate reactive oxygen species (ROS). Excess of ROS can cause serious damages to cells, including cell death. Thus, the objective of this work was to evaluate the lignocellulolytic enzymes produced by Pleurotus sajor-caju CCB020, Phanerochaete chrysosporium ATCC 28326, Trichoderma reesei RUT-C30, and Aspergillus niger IZ-9 grown in sugarcane bagasse and two yeast extract (YE) concentrations and characterize the antioxidant defense system of fungal cells by the activities of superoxide dismutase (SOD) and catalase (CAT). Pleurotus sajor-caju exhibited the highest activities of laccase and peroxidase in sugarcane bagasse with 2.6 g of YE and an increased activity of manganese peroxidase in sugarcane bagasse with 1.3 g of YE was observed. However, P. chrysosporium showed the highest activities of exoglucanase and endoglucanase in sugarcane bagasse with 1.3 g of YE. Lipid peroxidation and variations in SOD and CAT activities were observed during the production of lignocellulolytic enzymes and depending on the YE concentrations. The antioxidant defense system was induced in response to the oxidative stress caused by imbalances between the production and the detoxification of ROS.
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17
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Meng QS, Liu CG, Zhao XQ, Bai FW. Engineering Trichoderma reesei Rut-C30 with the overexpression of egl1 at the ace1 locus to relieve repression on cellulase production and to adjust the ratio of cellulolytic enzymes for more efficient hydrolysis of lignocellulosic biomass. J Biotechnol 2018; 285:56-63. [DOI: 10.1016/j.jbiotec.2018.09.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/06/2018] [Accepted: 09/03/2018] [Indexed: 01/25/2023]
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18
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Paramjeet S, Manasa P, Korrapati N. Biofuels: Production of fungal-mediated ligninolytic enzymes and the modes of bioprocesses utilizing agro-based residues. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2018. [DOI: 10.1016/j.bcab.2018.02.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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19
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Li YH, Zhang XY, Zhang F, Peng LC, Zhang DB, Kondo A, Bai FW, Zhao XQ. Optimization of cellulolytic enzyme components through engineering Trichoderma reesei and on-site fermentation using the soluble inducer for cellulosic ethanol production from corn stover. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:49. [PMID: 29483942 PMCID: PMC5824536 DOI: 10.1186/s13068-018-1048-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 02/12/2018] [Indexed: 05/05/2023]
Abstract
BACKGROUND Cellulolytic enzymes produced by Trichoderma reesei are widely studied for biomass bioconversion, and enzymatic components vary depending on different inducers. In our previous studies, a mixture of glucose and disaccharide (MGD) was developed and used to induce cellulase production. However, the enzymatic profile induced by MGD is still not defined, and further optimization of the enzyme cocktail is also required for efficient ethanol production from lignocellulosic biomass. RESULTS In this study, cellulolytic enzymes produced by T. reesei Rut C30 using MGD and alkali-pretreated corn stover (APCS) as inducer were compared. Cellular secretome in response to each inducer was analyzed, which revealed a similar enzyme profile. However, significant difference in the content of cellulases and xylanase was detected. Although MGD induction enhanced β-glucosidase production, its activity was still not sufficient for biomass hydrolysis. To overcome such a disadvantage, aabgl1 encoding β-glucosidase in Aspergillus aculeatus was heterologously expressed in T. reesei Rut C30 under the control of the pdc1 promoter. The recombinant T. reesei PB-3 strain showed an improved β-glucosidase activity of 310 CBU/mL in the fed-batch fermentation, 71-folds higher than that produced by the parent strain. Meanwhile, cellulase activity of 50 FPU/mL was detected. Subsequently, the crude enzyme was applied for hydrolyzing corn stover with a solid loading of 20% through separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation, respectively, for ethanol production. Better performance was observed in the SHF process, through which a total of 119.9 g/L glucose was released within 12 h for concomitant ethanol production of 54.2 g/L. CONCLUSIONS The similar profile of cellulolytic enzymes was detected under the induction of MGD and APCS, but higher amount of cellulases was present in the crude enzyme induced by MGD. However, β-glucosidase activity induced by MGD was not sufficient for hydrolyzing lignocellulosic biomass. High titers of cellulases and β-glucosidase were achieved simultaneously by heterologous expression of aabgl1 in T. reesei and fed-batch fermentation through feeding MGD. We demonstrated that on-site cellulase production by T. reesei PB-3 has a potential for efficient biomass saccharification and ethanol production from lignocellulosic biomass.
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Affiliation(s)
- Yong-Hao Li
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
- Present Address: School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology, Chongqing, 401331 China
| | - Xiao-Yue Zhang
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116023 China
| | - Fei Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Liang-Cai Peng
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Da-Bing Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Akihiko Kondo
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Kobe, 657-8501 Japan
| | - Feng-Wu Bai
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Xin-Qing Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
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Sun YX, Shen BB, Han HY, Lu Y, Zhang BX, Gao YF, Hu BZ, Hu XM. Screening of potential IL-tolerant cellulases and their efficient saccharification of IL-pretreated lignocelluloses. RSC Adv 2018; 8:30957-30965. [PMID: 35548722 PMCID: PMC9085512 DOI: 10.1039/c8ra05729j] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 08/22/2018] [Indexed: 11/21/2022] Open
Abstract
Lignocellulosic biomass as one of the most abundant and renewable resources has great potential for biofuel production. The complete conversion of biomass to biofuel is achieved through the effective pretreatment process and the following enzyme saccharification. Ionic liquids (ILs) are considered as a green solvent for lignocellulose pretreatment. However, ILs exhibit an inhibitory effect on cellulase activity, leading to a subsequent decrease in the efficiency of saccharification. The screening of new potential IL-tolerant cellulases is important. In the current study, a fungal strain with a relatively high cellulase production was isolated and identified as Penicillium oxalicum HC6. The culture conditions were optimized using corn stover and peptone as the carbon source and nitrogen source at pH 4.0 and 30 °C with an inoculation size of 2% (v/v) for 8 days. It was found that P. oxalicum HC6 exhibited potential salt tolerance with the increase of the enzyme production at a salt concentration of 5.0% (w/v). In addition, high enzyme activities were obtained at pH 4.0–6.0 and 50–65 °C. The crude enzyme from P. oxalicum HC6 with good thermal stability was also stable in the presence of salt and ILs. Good yields of reducing sugar were obtained by the crude enzyme from P. oxalicum HC6 after the saccharification of corn stover that was pretreated by ILs. P. oxalicum HC6 with potentially salt-tolerant and IL-tolerant enzymes has great potential application in the enzymatic saccharification of lignocellulose. Lignocellulosic biomass as one of the most abundant and renewable resources has great potential for biofuel production.![]()
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Affiliation(s)
- Yi-Xin Sun
- College of Life Science
- Northeast Agricultural University
- Harbin
- China
| | - Bing-Bing Shen
- College of Life Science
- Northeast Agricultural University
- Harbin
- China
| | - Hui-Ying Han
- College of Life Science
- Northeast Agricultural University
- Harbin
- China
| | - Yuan Lu
- College of Life Science
- Northeast Agricultural University
- Harbin
- China
| | - Bi-Xian Zhang
- Heilongjiang Academy of Agricultural Sciences
- Harbin
- China
| | - Yun-Fei Gao
- Heilongjiang Academy of Agricultural Sciences
- Harbin
- China
| | | | - Xiao-Mei Hu
- College of Life Science
- Northeast Agricultural University
- Harbin
- China
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21
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Zhang F, Zhao X, Bai F. Improvement of cellulase production in Trichoderma reesei Rut-C30 by overexpression of a novel regulatory gene Trvib-1. BIORESOURCE TECHNOLOGY 2018; 247:676-683. [PMID: 30060399 DOI: 10.1016/j.biortech.2017.09.126] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/17/2017] [Accepted: 09/18/2017] [Indexed: 05/05/2023]
Abstract
Trichoderma reesei is a widely used cellulase producer, and development of robust strains for improved cellulase production is of great interest. In this study, the gene Trvib-1 encoding a putative transcription factor was overexpressed in T. reesei Rut-C30, and effects on cellulase production by the manipulation as well as corn stover degradation by the crude enzyme were investigated. Cellulase production and protein secretion were significantly improved in the culture of the recombinant T. reesei Vib-1, which were 200% and 219%, respectively, higher than that produced by the parent strain. Cellulase induction was enhanced in the presence of pure cellulose as well as various soluble inducers. Glucose released from the pretreated corn stover hydrolyzed by the crude enzyme in the recombinant strain was improved 40%. These results indicate that the overexpression of Trvib-1 is a feasible strategy for producing cellulase to enhance bioconversion efficiency of lignocellulosic biomass.
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Affiliation(s)
- Fei Zhang
- State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xinqing Zhao
- State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Fengwu Bai
- State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
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22
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Singhania RR, Patel AK, Pandey A, Ganansounou E. Genetic modification: A tool for enhancing beta-glucosidase production for biofuel application. BIORESOURCE TECHNOLOGY 2017; 245:1352-1361. [PMID: 28596076 DOI: 10.1016/j.biortech.2017.05.126] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/17/2017] [Accepted: 05/19/2017] [Indexed: 05/25/2023]
Abstract
Beta-glucosidase (BGL) is a rate-limiting enzyme for cellulose hydrolysis as it acts in the final step of lignocellulosic biomass conversion to convert cellobiose into glucose, the final end product. Most of the fungal strains used for cellulase production are deficient in BGL hence BGL is supplemented into cellulases to have an efficient biomass conversion. Genetic engineering has enabled strain modification to produce BGL optimally with desired properties to be employed for biofuel applications. It has been cloned either directly into the host strains lacking BGL or into another expression system, to be overexpressed so as to be blended into BGL deficient cellulases. In this article, role of genetic engineering to overcome BGL limitations in the cellulase cocktail and its significance for biofuel applications has been critically reviewed.
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Affiliation(s)
- Reeta Rani Singhania
- DBT-IOC Advanced Bio-Energy Research Centre, Indian Oil Corporation; R&D Centre, Sector-13, Faridabad 121007, India
| | - Anil Kumar Patel
- Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu 96822, HI, United States.
| | - Ashok Pandey
- Center of Innovative and Applied Bioprocessing, Sector 81, Knowledge City PO Manauli, SAS Nagar, Mohali 140306, Punjab, India
| | - Edgard Ganansounou
- Bioenergy and Energy Planning Research Group, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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23
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Gao J, Qian Y, Wang Y, Qu Y, Zhong Y. Production of the versatile cellulase for cellulose bioconversion and cellulase inducer synthesis by genetic improvement of Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:272. [PMID: 29167702 PMCID: PMC5688634 DOI: 10.1186/s13068-017-0963-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 11/07/2017] [Indexed: 05/05/2023]
Abstract
BACKGROUND The enzymes for efficient hydrolysis of lignocellulosic biomass are a major factor in the development of an economically feasible cellulose bioconversion process. Up to now, low hydrolysis efficiency and high production cost of cellulases remain the significant hurdles in this process. The aim of the present study was to develop a versatile cellulase system with the enhanced hydrolytic efficiency and the ability to synthesize powerful inducers by genetically engineering Trichoderma reesei. RESULTS In our study, we employed a systematic genetic strategy to construct the carbon catabolite-derepressed strain T. reesei SCB18 to produce the cellulase complex that exhibited a strong cellulolytic capacity for biomass saccharification and an extraordinary high β-glucosidase (BGL) activity for cellulase-inducing disaccharides synthesis. We first identified the hypercellulolytic and uracil auxotrophic strain T. reesei SP4 as carbon catabolite repressed, and then deleted the carbon catabolite repressor gene cre1 in the genome. We found that the deletion of cre1 with the selectable marker pyrG led to a 72.6% increase in total cellulase activity, but a slight reduction in saccharification efficiency. To facilitate the following genetic modification, the marker pyrG was successfully removed by homologous recombination based on resistance to 5-FOA. Furthermore, the Aspergillus niger BGLA-encoding gene bglA was overexpressed, and the generated strain T. reesei SCB18 exhibited a 29.8% increase in total cellulase activity and a 51.3-fold enhancement in BGL activity (up to 103.9 IU/mL). We observed that the cellulase system of SCB18 showed significantly higher saccharification efficiency toward differently pretreated corncob residues than the control strains SDC11 and SP4. Moreover, the crude enzyme preparation from SCB18 with high BGL activity possessed strong transglycosylation ability to synthesize β-disaccharides from glucose. The transglycosylation product was finally utilized as the inducer for cellulase production, which provided a 63.0% increase in total cellulase activity compared to the frequently used soluble inducer, lactose. CONCLUSIONS In summary, we constructed a versatile cellulase system in T. reesei for efficient biomass saccharification and powerful cellulase inducer synthesis by combinational genetic manipulation of three distinct types of genes to achieve the customized cellulase production, thus providing a viable strategy for further strain improvement to reduce the cost of biomass-based biofuel production.
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Affiliation(s)
- Jia Gao
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100 People’s Republic of China
| | - Yuanchao Qian
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100 People’s Republic of China
| | - Yifan Wang
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100 People’s Republic of China
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100 People’s Republic of China
| | - Yaohua Zhong
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100 People’s Republic of China
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Druzhinina IS, Kubicek CP. Genetic engineering of Trichoderma reesei cellulases and their production. Microb Biotechnol 2017; 10:1485-1499. [PMID: 28557371 PMCID: PMC5658622 DOI: 10.1111/1751-7915.12726] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 04/11/2017] [Accepted: 04/11/2017] [Indexed: 11/26/2022] Open
Abstract
Lignocellulosic biomass, which mainly consists of cellulose, hemicellulose and lignin, is the most abundant renewable source for production of biofuel and biorefinery products. The industrial use of plant biomass involves mechanical milling or chipping, followed by chemical or physicochemical pretreatment steps to make the material more susceptible to enzymatic hydrolysis. Thereby the cost of enzyme production still presents the major bottleneck, mostly because some of the produced enzymes have low catalytic activity under industrial conditions and/or because the rate of hydrolysis of some enzymes in the secreted enzyme mixture is limiting. Almost all of the lignocellulolytic enzyme cocktails needed for the hydrolysis step are produced by fermentation of the ascomycete Trichoderma reesei (Hypocreales). For this reason, the structure and mechanism of the enzymes involved, the regulation of their expression and the pathways of their formation and secretion have been investigated in T. reesei in considerable details. Several of the findings thereby obtained have been used to improve the formation of the T. reesei cellulases and their properties. In this article, we will review the achievements that have already been made and also show promising fields for further progress.
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Affiliation(s)
- Irina S. Druzhinina
- Microbiology GroupResearch Area Biochemical TechnologyInstitute of Chemical, Environmental and Biological EngineeringTU WienViennaAustria
| | - Christian P. Kubicek
- Microbiology GroupResearch Area Biochemical TechnologyInstitute of Chemical, Environmental and Biological EngineeringTU WienViennaAustria
- Present address:
Steinschötelgasse 7Wien1100Austria
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25
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Kim SK, Chung D, Himmel ME, Bomble YJ, Westpheling J. Heterologous expression of a β-D-glucosidase in Caldicellulosiruptor bescii has a surprisingly modest effect on the activity of the exoproteome and growth on crystalline cellulose. J Ind Microbiol Biotechnol 2017; 44:1643-1651. [PMID: 28942503 DOI: 10.1007/s10295-017-1982-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 09/14/2017] [Indexed: 11/28/2022]
Abstract
Members of the genus Caldicellulosiruptor are the most thermophilic cellulolytic bacteria so far described and are capable of efficiently utilizing complex lignocellulosic biomass without conventional pretreatment. Previous studies have shown that accumulation of high concentrations of cellobiose and, to a lesser extent, cellotriose, inhibits cellulase activity both in vivo and in vitro and high concentrations of cellobiose are present in C. bescii fermentations after 90 h of incubation. For some cellulolytic microorganisms, β-D-glucosidase is essential for the efficient utilization of cellobiose as a carbon source and is an essential enzyme in commercial preparations for efficient deconstruction of plant biomass. In spite of its ability to grow efficiently on crystalline cellulose, no extracellular β-D-glucosidase or its GH1 catalytic domain could be identified in the C. bescii genome. To investigate whether the addition of a secreted β-D-glucosidase would improve growth and cellulose utilization by C. bescii, we cloned and expressed a thermostable β-D-glucosidase from Acidothermus cellulolyticus (Acel_0133) in C. bescii using the CelA signal sequence for protein export. The effect of this addition was modest, suggesting that β-D-glucosidase is not rate limiting for cellulose deconstruction and utilization by C. bescii.
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Affiliation(s)
- Sun-Ki Kim
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA.,The BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Daehwan Chung
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, USA.,The BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Michael E Himmel
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, USA.,The BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Yannick J Bomble
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, USA.,The BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Janet Westpheling
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA. .,The BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
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Influence of Randomly Inserted Feruloyl Esterase A on β-Glucosidase Activity in Trichoderma reesei. Appl Biochem Biotechnol 2017; 183:254-264. [DOI: 10.1007/s12010-017-2442-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 02/17/2017] [Indexed: 10/20/2022]
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Li C, Lin F, Zhou L, Qin L, Li B, Zhou Z, Jin M, Chen Z. Cellulase hyper-production by Trichoderma reesei mutant SEU-7 on lactose. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:228. [PMID: 29034003 PMCID: PMC5628480 DOI: 10.1186/s13068-017-0915-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 09/23/2017] [Indexed: 05/13/2023]
Abstract
BACKGROUND The induction of cellulase production by insoluble carbon source cellulose was a common and efficient strategy, but has some drawbacks, such as difficult fermentation operation, substantial cellulase loss, long fermentation time, and high energy-consumption, resulting in high cost of cellulase production in industry. These drawbacks can be overcome if soluble carbon sources are utilized as the inducers for cellulase production. However, until now the induction efficiency of most soluble carbon sources, especially lactose and glucose, is still inferior to cellulose despite extensive efforts have been made by either optimizing the fermentation process or constructing the recombinant strains. Therefore, strain improvement by metabolic engineering for high induction efficiency of soluble carbon sources is of great interest. RESULTS Trichoderma reesei mutant SEU-7 was constructed from T. reesei RUT-C30 with the overexpression of endogenous gene β-glucosidase (BGL1) by insertional mutagenesis via Agrobacterium tumefaciens-mediated transformation (AMT). Compared to RUT-C30, SEU-7 displays substantially enhanced activities of both cellulase and hemicellulase when grown on either lactose or cellulose. The induction efficiency with lactose was found to be higher than cellulose in strain SEU-7. To the best of our knowledge, we achieved the highest FPase activity in SEU-7 in both batch culture (13.0 IU/mL) and fed-batch culture (47.0 IU/mL) on lactose. Moreover, SEU-7 displayed unrivaled pNPGase activity on lactose in both batch culture (81.0 IU/mL) and fed-batch culture (144.0 IU/mL) as compared to the other reported T. reesei strains in the literature grown in batch or fed-batch experiments on cellulose or lactose. This superiority of SEU-7 over RUT-C30 improves markedly the saccharification ability of SEU-7 on pretreated corn stover. The overexpression of gene BGL1 was found either at the mRNA or at the protein level in the mutant strains with increased cellulase production in comparison with RUT-C30, but only SEU-7 displayed much higher expression of gene BGL1 on lactose than on cellulose. Two copies of gene BGL1 were inserted into the chromosome of T. reesei SEU-7 between KI911141.1:347357 and KI911141.1:347979, replacing the original 623-bp fragment that is not within any genes' coding region. The qRT-PCR analysis revealed that the mRNA levels of both cellulase and hemicellulase were upregulated significantly in SEU-7, together with the MFS transporter CRT1 and the XYR1 nuclear importer KAP8. CONCLUSIONS Recombinant T. reesei SEU-7 displays hyper-production of both cellulase and hemicellulase on lactose with the highest FPase activity and pNPGase activity for T. reesei, enabling highly efficient saccharification of pretreated biomass. For the first time, the induction efficiency for cellulase production by lactose in T. reesei was reported to be higher than that by cellulose. This outperformance of T. reesei SEU-7, which is strain-specific, is attributed to both the overexpression of gene BGL and the collateral mutation. Moreover, the increased transcription levels of cellulase genes, the related transcription factors, and the MFS transporter CRT1 contribute to the outstanding cellulase production of SEU-7. Our research advances strain improvement to enhance the induction efficiency of soluble carbon sources to produce cost-effective cellulase and hemicellulase in industry.
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Affiliation(s)
- Chengcheng Li
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096 China
| | - Fengming Lin
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096 China
- 35 Jinxianghe Road, Xuanwu District, Nanjing, 210008 Jiangsu Province China
| | - Le Zhou
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096 China
| | - Lei Qin
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Nankai District, Tianjin, 300072 People’s Republic of China
| | - Bingzhi Li
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Nankai District, Tianjin, 300072 People’s Republic of China
| | - Zhihua Zhou
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032 China
| | - Mingjie Jin
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094 China
| | - Zhan Chen
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI 48109 USA
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Ellilä S, Fonseca L, Uchima C, Cota J, Goldman GH, Saloheimo M, Sacon V, Siika-aho M. Development of a low-cost cellulase production process using Trichoderma reesei for Brazilian biorefineries. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:30. [PMID: 28184245 PMCID: PMC5289010 DOI: 10.1186/s13068-017-0717-0] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 01/25/2017] [Indexed: 05/21/2023]
Abstract
BACKGROUND During the past few years, the first industrial-scale cellulosic ethanol plants have been inaugurated. Although the performance of the commercial cellulase enzymes used in this process has greatly improved over the past decade, cellulases still represent a very significant operational cost. Depending on the region, transport of cellulases from a central production facility to a biorefinery may significantly add to enzyme cost. The aim of the present study was to develop a simple, cost-efficient cellulase production process that could be employed locally at a Brazilian sugarcane biorefinery. RESULTS Our work focused on two main topics: growth medium formulation and strain improvement. We evaluated several Brazilian low-cost industrial residues for their potential in cellulase production. Among the solid residues evaluated, soybean hulls were found to display clearly the most desirable characteristics. We engineered a Trichoderma reesei strain to secrete cellulase in the presence of repressing sugars, enabling the use of sugarcane molasses as an additional carbon source. In addition, we added a heterologous β-glucosidase to improve the performance of the produced enzymes in hydrolysis. Finally, the addition of an invertase gene from Aspegillus niger into our strain allowed it to consume sucrose from sugarcane molasses directly. Preliminary cost analysis showed that the overall process can provide for very low-cost enzyme with good hydrolysis performance on industrially pre-treated sugarcane straw. CONCLUSIONS In this study, we showed that with relatively few genetic modifications and the right growth medium it is possible to produce considerable amounts of well-performing cellulase at very low cost in Brazil using T. reesei. With further enhancements and optimization, such a system could provide a viable alternative to delivered commercial cellulases.
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Affiliation(s)
- Simo Ellilä
- VTT Brasil Ltda., Barueri, Sao Paulo Brazil
- VTT Technical Research Centre of Finland, Tietotie 2, 02044 Espoo, Finland
| | | | | | - Junio Cota
- VTT Brasil Ltda., Barueri, Sao Paulo Brazil
- Instituto de Ciências Agrárias, Universidade Federal de Minas Gerais (UFMG), Montes Claros, MG Brazil
| | - Gustavo Henrique Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de Sao Paulo, Ribeirão Preto, SP Brazil
| | - Markku Saloheimo
- VTT Technical Research Centre of Finland, Tietotie 2, 02044 Espoo, Finland
| | - Vera Sacon
- VTT Brasil Ltda., Barueri, Sao Paulo Brazil
| | - Matti Siika-aho
- VTT Technical Research Centre of Finland, Tietotie 2, 02044 Espoo, Finland
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Xiong L, Kameshwar AKS, Chen X, Guo Z, Mao C, Chen S, Qin W. The ACEII recombinant Trichoderma reesei QM9414 strains with enhanced xylanase production and its applications in production of xylitol from tree barks. Microb Cell Fact 2016; 15:215. [PMID: 28031033 PMCID: PMC5192574 DOI: 10.1186/s12934-016-0614-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Accepted: 12/06/2016] [Indexed: 01/08/2023] Open
Abstract
Background ACEII transcription factor plays a significant role in regulating the expression of cellulase and hemicellulase encoding genes. Apart from ACEII, transcription factors such as XYR1, CRE1, HAP2/3/5 complex and ACEI function in a coordinated pattern for regulating the gene expression of cellulases and hemicellulases. Studies have demonstrated that ACEII gene deletion results in decreased total cellulase and xylanase activities with reduced transcript levels of lignocellulolytic enzymes. Results In this study, we have successfully transformed the ACEII transcription factor encoding gene in Trichoderma reesei to significantly improve its degrading abilities. Transformation experiments on parental strain T. reesei QM9414 has resulted in five genetically engineered strains T/Ace2-2, T/Ace2-5, T/Ace2-8, T/Ace5-4 and T/Ace10-1. Among which, T/Ace2-2 has exhibited significant increase in enzyme activity by twofolds, when compared to parental strain. The T/Ace2-2 was cultured on growth substrates containing 2% bark supplemented with (a) sugar free + MA medium (b) glucose + MA medium and (c) xylose + MA medium. The bark degradation efficiency of genetically modified T/Ace2-2 strain was assessed by analyzing the xylitol production yield using HPAEC. By 6th day, about 10.52 g/l of xylitol was produced through enzymatic conversion of bark (2% bark + MA + xylose) by the T/Ace2-2 strain and by 7th day the conversion rate was found to be 0.21 g/g. Obtained results confirmed that bark growth medium supplemented with d-xylose has profoundly increased the conversion rate of bark by T/Ace2-2 strain when compared to sugar free and glucose supplemented growth media. Results obtained from scanning electron microscopy has endorsed our current results. Bark samples inoculated with T/Ace2-2 strain has showed large number of degraded cells with clearly visible cavities and fractures, by exposing the microfibrillar interwoven complex. Conclusion We propose a cost effective and ecofriendly method for the degradation of lignocellulosic biomass such as bark to produce xylitol by using genetically modified T. reesei. Efficient conversion rate and production yield obtained in our current study provides a great scope for the xylitol industries, as our method bypasses the pretreatment of bark achieving clean and low-cost xylitol production.
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Affiliation(s)
- Lili Xiong
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu City, 610031, Sichuan Province, China.,Department of Biology, Lakehead University, Thunder Bay, ON, P7B 5E1, Canada
| | | | - Xi Chen
- State Key Laboratory for Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Zhiyun Guo
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu City, 610031, Sichuan Province, China
| | - Canquan Mao
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu City, 610031, Sichuan Province, China
| | - Sanfeng Chen
- State Key Laboratory for Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Wensheng Qin
- Department of Biology, Lakehead University, Thunder Bay, ON, P7B 5E1, Canada.
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Wanmolee W, Sornlake W, Rattanaphan N, Suwannarangsee S, Laosiripojana N, Champreda V. Biochemical characterization and synergism of cellulolytic enzyme system from Chaetomium globosum on rice straw saccharification. BMC Biotechnol 2016; 16:82. [PMID: 27871321 PMCID: PMC5117696 DOI: 10.1186/s12896-016-0312-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 11/01/2016] [Indexed: 12/16/2022] Open
Abstract
Background Efficient hydrolysis of lignocellulosic materials to sugars for conversion to biofuels and chemicals is a key step in biorefinery. Designing an active saccharifying enzyme system with synergy among their components is considered a promising approach. Results In this study, a lignocellulose-degrading enzyme system of Chaetomium globosum BCC5776 (CG-Cel) was characterized for its activity and proteomic profiles, and synergism with accessory enzymes. The highest cellulase productivity of 0.40 FPU/mL was found for CG-Cel under the optimized submerged fermentation conditions on 1% (w/v) EPFB (empty palm fruit bunch), 2% microcrystalline cellulose (Avicel®) and 1% soybean meal (SBM) at 30 °C, pH 5.8 for 6 d. CG-Cel worked optimally at 50–60 °C in an acidic pH range. Proteomics analysis by LC/MS/MS revealed a complex enzyme system composed of core cellulases and accessory hydrolytic/non-hydrolytic enzymes attacking plant biopolymers. A synergistic enzyme system comprising the CG-Cel, a β-glucosidase (Novozyme® 188) and a hemicellulase Accellerase® XY was optimized on saccharification of alkaline-pretreated rice straw by a mixture design approach. Applying a full cubic model, the optimal ratio of ternary enzyme mixture containing CG-Cel: Novozyme® 188: Accellerase® XY of 44.4:20.6:35.0 showed synergistic enhancement on reducing sugar yield with a glucose releasing efficiency of 256.4 mg/FPU, equivalent to a 2.9 times compared with that from CG-Cel alone. Conclusions The work showed an approach for developing an active synergistic enzyme system based on the newly characterized C. globosum for lignocellulose saccharification and modification in bio-industries. Electronic supplementary material The online version of this article (doi:10.1186/s12896-016-0312-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Wanwitoo Wanmolee
- The Joint Graduate School for Energy and Environment (JGSEE), King Mongkut's University of Technology Thonburi, Prachauthit Road, Bangmod, Bangkok, 10140, Thailand
| | - Warasirin Sornlake
- Enzyme Technology Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathumthani, 12120, Thailand
| | - Nakul Rattanaphan
- Bioprocess Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathumthani, 12120, Thailand
| | - Surisa Suwannarangsee
- Enzyme Technology Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathumthani, 12120, Thailand
| | - Navadol Laosiripojana
- The Joint Graduate School for Energy and Environment (JGSEE), King Mongkut's University of Technology Thonburi, Prachauthit Road, Bangmod, Bangkok, 10140, Thailand.,BIOTEC-JGSEE Integrative Biorefinery Laboratory, Innovation Cluster 2 Building, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathumthani, 12120, Thailand
| | - Verawat Champreda
- Enzyme Technology Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathumthani, 12120, Thailand. .,BIOTEC-JGSEE Integrative Biorefinery Laboratory, Innovation Cluster 2 Building, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathumthani, 12120, Thailand.
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Zhang F, Bai F, Zhao X. Enhanced cellulase production from Trichoderma reesei Rut-C30 by engineering with an artificial zinc finger protein library. Biotechnol J 2016; 11:1282-1290. [PMID: 27578229 DOI: 10.1002/biot.201600227] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Revised: 08/25/2016] [Accepted: 08/29/2016] [Indexed: 01/03/2023]
Abstract
Trichoderma reesei Rut-C30 is a well-known cellulase producer, and improvement of its cellulase production is of great interest. An artificial zinc finger protein (AZFP) library is constructed for expression in T. reesei Rut-C30, and a mutant strain T. reesei U3 is selected based on its enhanced cellulase production. The U3 mutant shows a 55% rise in filter paper activity and 8.1-fold increased β-glucosidase activity, when compared to the native strain T. reesei Rut-C30. It is demonstrated that enhanced β-glucosidase activity was due to elevated transcription level of β-glucosidase gene in the U3 mutant. Moreover, significant elevation in transcription levels of several putative Azfp-U3 target genes is detected in the U3 mutant, including genes encoding hypothetical transcription factors and a putative glycoside hydrolase. Furthermore, U3 cellulase shows 115% higher glucose yield from pretreated corn stover, when compared to the cellulase of T. reesei Rut-C30. These results demonstrate that AZFP can be used to improve cellulase production in T. reesei Rut-C30. Our current work offers the establishment of an alternative strategy to develop fungal cell factories for improved production of high value industrial products.
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Affiliation(s)
- Fei Zhang
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, China
| | - Fengwu Bai
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, China.,State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xinqing Zhao
- State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
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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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Xue X, Wu Y, Qin X, Ma R, Luo H, Su X, Yao B. Revisiting overexpression of a heterologous β-glucosidase in Trichoderma reesei: fusion expression of the Neosartorya fischeri Bgl3A to cbh1 enhances the overall as well as individual cellulase activities. Microb Cell Fact 2016; 15:122. [PMID: 27400964 PMCID: PMC4939661 DOI: 10.1186/s12934-016-0520-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 06/30/2016] [Indexed: 12/03/2022] Open
Abstract
Background The filamentous fungus Trichoderma reesei has the capacity to secret large amounts of cellulase and is widely used in a variety of industries. However, the T. reesei cellulase is weak in β-glucosidase activity, which results in accumulation of cellobiose inhibiting the endo- and exo-cellulases. By expressing an exogenous β-glucosidase gene, the recombinant T. reesei cellulase is expected to degrade cellulose into glucose more efficiently. Results The thermophilic β-glucosidase NfBgl3A from Neosartorya fischeri is chosen for overexpression in T. reesei due to its robust activity. In vitro, the Pichia pastoris-expressed NfBgl3A aided the T. reesei cellulase in releasing much more glucose with significantly lower amounts of cellobiose from crystalline cellulose. The NfBgl3A gene was hence fused to the cbh1 structural gene and assembled between the strong cbh1 promoter and cbh1 terminator to obtain pRS-NfBgl3A by using the DNA assembler method. pRS-NfBgl3A was transformed into the T. reesei uridine auxotroph strain TU-6. Six positive transformants showed β-glucosidase activities of 2.3–69.7 U/mL (up to 175-fold higher than that of wild-type). The largely different β-glucosidase activities in the transformants may be ascribed to the gene copy numbers of NfBgl3A or its integration loci. The T. reesei-expressed NfBgl3A showed highly similar biochemical properties to that expressed in P. pastoris. As expected, overexpression of NfBgl3A enhanced the overall cellulase activity of T. reesei. The CBHI activity in all transformants increased, possibly due to the extra copies of cbh1 gene introduced, while the endoglucanase activity in three transformants also largely increased, which was not observed in any other studies overexpressing a β-glucosidase. NfBgl3A had significant transglycosylation activity, generating sophorose, a potent cellulase inducer, and other oligosaccharides from glucose and cellobiose. Conclusions We report herein the successful overexpression of a thermophilic N. fischeri β-glucosidase in T. reesei. In the same time, the fusion of NfBgl3A to the cbh1 gene introduced extra copies of the cellobiohydrolase 1 gene. As a result, we observed improved β-glucosidase and cellobiohydrolase activity as well as the overall cellulase activity. In addition, the endoglucanase activity also increased in some of the transformants. Our results may shed light on design of more robust T. reesei cellulases.
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Affiliation(s)
- Xianli Xue
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Beijing, 100081, People's Republic of China
| | - Yilan Wu
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, People's Republic of China
| | - Xing Qin
- College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, People's Republic of China
| | - Rui Ma
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Beijing, 100081, People's Republic of China
| | - Huiying Luo
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Beijing, 100081, People's Republic of China
| | - Xiaoyun Su
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Beijing, 100081, People's Republic of China.
| | - Bin Yao
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Beijing, 100081, People's Republic of China.
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Singh G, Verma AK, Kumar V. Catalytic properties, functional attributes and industrial applications of β-glucosidases. 3 Biotech 2016; 6:3. [PMID: 28330074 PMCID: PMC4697909 DOI: 10.1007/s13205-015-0328-z] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 06/19/2015] [Indexed: 12/18/2022] Open
Abstract
β-Glucosidases are diverse group of enzymes with great functional importance to biological systems. These are grouped in multiple glycoside hydrolase families based on their catalytic and sequence characteristics. Most studies carried out on β-glucosidases are focused on their industrial applications rather than their endogenous function in the target organisms. β-Glucosidases performed many functions in bacteria as they are components of large complexes called cellulosomes and are responsible for the hydrolysis of short chain oligosaccharides and cellobiose. In plants, β-glucosidases are involved in processes like formation of required intermediates for cell wall lignification, degradation of endosperm’s cell wall during germination and in plant defense against biotic stresses. Mammalian β-glucosidases are thought to play roles in metabolism of glycolipids and dietary glucosides, and signaling functions. These enzymes have diverse biotechnological applications in food, surfactant, biofuel, and agricultural industries. The search for novel and improved β-glucosidase is still continued to fulfills demand of an industrially suitable enzyme. In this review, a comprehensive overview on detailed functional roles of β-glucosidases in different organisms, their industrial applications, and recent cloning and expression studies with biochemical characterization of such enzymes is presented for the better understanding and efficient use of diverse β-glucosidases.
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Affiliation(s)
- Gopal Singh
- Institute of Himalayan Bioresource Technology, Palampur, 176062, India
| | - A K Verma
- Department of Biochemistry, College of Basic Sciences and Humanities, G. B. Pant University of Agriculture and Technology, Pantnagar, 263145, India
| | - Vinod Kumar
- Department of Biotechnology, Akal College of Agriculture, Eternal University, Baru Sahib, Sirmour, 173101, India.
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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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Larue K, Melgar M, Martin VJJ. Directed evolution of a fungal β-glucosidase in Saccharomyces cerevisiae. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:52. [PMID: 26949413 PMCID: PMC4778352 DOI: 10.1186/s13068-016-0470-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/22/2016] [Indexed: 05/13/2023]
Abstract
BACKGROUND β-glucosidases (BGLs) catalyze the hydrolysis of soluble cellodextrins to glucose and are a critical component of cellulase systems. In order to engineer Saccharomyces cerevisiae for the production of ethanol from cellulosic biomass, a BGL tailored to industrial bioconversions is needed. RESULTS We applied a directed evolution strategy to a glycosyl hydrolase family 3 (GH3) BGL from Aspergillus niger (BGL1) by expressing a library of mutated bgl1 genes in S. cerevisiae and used a two-step functional screen to identify improved enzymes. Twelve BGL variants that supported growth of S. cerevisiae on cellobiose and showed increased activity on the synthetic substrate p-nitrophenyl-β-D-glucopyranoside were identified and characterized. By performing kinetic experiments, we found that a Tyr → Cys substitution at position 305 of BGL1 dramatically reduced transglycosidation activity that causes inhibition of the hydrolytic reaction at high substrate concentrations. Targeted mutagenesis demonstrated that the position 305 residue is critical in GH3 BGLs and likely determines the extent to which transglycosidation reactions occur. We also found that a substitution at Gln(140) reduced the inhibitory effect of glucose and could be combined with the Y305C substitution to produce a BGL with decreased sensitivity to both the product and substrate. Using the crystal structure of a GH3 BGL from A. aculeatus, we mapped a group of beneficial mutations to the β/α domain of the molecule and postulate that this region modulates activity through subunit interactions. Six BGL variants were identified with substitutions in the MFα pre-sequence that was used to mediate secretion of the protein. Substitutions at Pro(21) or Val(22) of the MFα pre-sequence could produce up to a twofold increase in supernatant hydrolase activity and provides evidence that expression and/or secretion was an additional factor limiting hydrolytic activity. CONCLUSIONS Using directed evolution on BGL1, we identified a key residue that controls hydrolytic and transglycosidation reactions in GH3 BGLs. We also found that several beneficial mutations could be combined and increased the hydrolytic activity for both synthetic and natural substrates.
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Affiliation(s)
- Kane Larue
- Department of Biology, Centre for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke West, Montreal, QC H4B 1R6 Canada
| | - Mindy Melgar
- Department of Biology, Centre for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke West, Montreal, QC H4B 1R6 Canada
| | - Vincent J. J. Martin
- Department of Biology, Centre for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke West, Montreal, QC H4B 1R6 Canada
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Fungal Biotechnology for Industrial Enzyme Production: Focus on (Hemi)cellulase Production Strategies, Advances and Challenges. Fungal Biol 2016. [DOI: 10.1007/978-3-319-27951-0_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Santos CA, Zanphorlin LM, Crucello A, Tonoli CCC, Ruller R, Horta MAC, Murakami MT, de Souza AP. Crystal structure and biochemical characterization of the recombinant ThBgl, a GH1 β-glucosidase overexpressed in Trichoderma harzianum under biomass degradation conditions. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:71. [PMID: 27006690 PMCID: PMC4802607 DOI: 10.1186/s13068-016-0487-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Accepted: 03/14/2016] [Indexed: 05/07/2023]
Abstract
BACKGROUND The conversion of biomass-derived sugars via enzymatic hydrolysis for biofuel production is a challenge. Therefore, the search for microorganisms and key enzymes that increase the efficiency of the saccharification of cellulosic substrates remains an important and high-priority area of study. Trichoderma harzianum is an important fungus known for producing high levels of cellulolytic enzymes that can be used for cellulosic ethanol production. In this context, β-glucosidases, which act synergistically with cellobiohydrolases and endo-β-1,4-glucanases in the saccharification process, are potential biocatalysts for the conversion of plant biomass to free glucose residues. RESULTS In the present study, we used RNA-Seq and genomic data to identify the major β-glucosidase expressed by T. harzianum under biomass degradation conditions. We mapped and quantified the expression of all of the β-glucosidases from glycoside hydrolase families 1 and 3, and we identified the enzyme with the highest expression under these conditions. The target gene was cloned and heterologously expressed in Escherichia coli, and the recombinant protein (rThBgl) was purified with high yields. rThBgl was characterized using a comprehensive set of biochemical, spectroscopic, and hydrodynamic techniques. Finally, we determined the crystallographic structure of the recombinant protein at a resolution of 2.6 Å. CONCLUSIONS Using a rational approach, we investigated the biochemical characteristics and determined the three-dimensional protein structure of a β-glucosidase that is highly expressed by T. harzianum under biomass degradation conditions. The methodology described in this manuscript will be useful for the bio-prospection of key enzymes, including cellulases and other accessory enzymes, for the development and/or improvement of enzymatic cocktails designed to produce ethanol from plant biomass.
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Affiliation(s)
- Clelton A. Santos
- />Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas, SP Brazil
| | - Letícia M. Zanphorlin
- />Laboratório Nacional de Ciência e Tecnologia do Bioetanol, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, SP Brazil
| | - Aline Crucello
- />Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas, SP Brazil
| | - Celisa C. C. Tonoli
- />Laboratório Nacional de Biociências, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, SP Brazil
| | - Roberto Ruller
- />Laboratório Nacional de Ciência e Tecnologia do Bioetanol, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, SP Brazil
| | - Maria A. C. Horta
- />Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas, SP Brazil
| | - Mario T. Murakami
- />Laboratório Nacional de Biociências, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, SP Brazil
| | - Anete Pereira de Souza
- />Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas, SP Brazil
- />Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP Brazil
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Baba Y, Sumitani JI, Tani S, Kawaguchi T. Characterization of Aspergillus aculeatus β-glucosidase 1 accelerating cellulose hydrolysis with Trichoderma cellulase system. AMB Express 2015; 5:3. [PMID: 25642400 PMCID: PMC4305095 DOI: 10.1186/s13568-014-0090-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 12/23/2014] [Indexed: 11/10/2022] Open
Abstract
Aspergillus aculeatus β-glucosidase 1 (AaBGL1), which promotes cellulose hydrolysis by Trichoderma cellulase system, was characterized and compared some properties to a commercially supplied orthologue in A. niger (AnBGL) to elucidate advantages of recombinant AaBGL1 (rAaBGL1) for synergistic effect on Trichoderma enzymes. Steady-state kinetic studies revealed that rAaBGL1 showed high catalytic efficiency towards β-linked glucooligosaccharides. Up to a degree of polymerization (DP) 3, rAaBGL1 prefered to hydrolyze β-1,3 linked glucooligosaccharides, but longer than DP 3, preferred β-1,4 glucooligosaccharides (up to DP 5). This result suggested that there were different formation for subsites in the catalytic cleft of AaBGL1 between β-1,3 and β-1,4 glucooligosaccharides, therefore rAaBGL1 preferred short chain of laminarioligosaccharides and long chain of cellooligosaccharides on hydrolysis. rAaBGL1 was more insensitive to glucose inhibition and more efficient to hydrolyze the one of major transglycosylation product, gentiobiose than AnBGL, resulting that rAaBGL1 completely hydrolyzed 5% cellobiose to glucose faster than AnBGL. These data indicate that AaBGL1 is valuable for the use of cellulosic biomass conversion.
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Enhanced hydrolysis of lignocellulosic biomass: Bi-functional enzyme complexes expressed inPichia pastorisimprove bioethanol production fromMiscanthus sinensis. Biotechnol J 2015; 10:1912-9. [DOI: 10.1002/biot.201500081] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Revised: 07/17/2015] [Accepted: 10/26/2015] [Indexed: 01/13/2023]
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Zoglowek M, Lübeck PS, Ahring BK, Lübeck M. Heterologous expression of cellobiohydrolases in filamentous fungi – An update on the current challenges, achievements and perspectives. Process Biochem 2015. [DOI: 10.1016/j.procbio.2014.12.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Heterologous protein expression in Hypocrea jecorina: a historical perspective and new developments. Biotechnol Adv 2014; 33:142-154. [PMID: 25479282 DOI: 10.1016/j.biotechadv.2014.11.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 11/18/2014] [Accepted: 11/23/2014] [Indexed: 10/24/2022]
Abstract
Hypocrea jecorina, the sexual teleomorph of Trichoderma reesei, has long been favored as an industrial cellulase producer, first utilizing its native cellulase system and later augmented by the introduction of heterologous enzymatic activities or improved variants of native enzymes. Expression of heterologous proteins in H. jecorina was once considered difficult when the target was an improved variant of a native cellulase. Developments over the past nearly 30 years have produced strains, vectors, and selection mechanisms that have continued to simplify and streamline heterologous protein expression in this fungus. More recent developments in fungal molecular biology have pointed the way toward a fundamental transformation in the ease and efficiency of heterologous protein expression in this important industrial host. Here, 1) we provide a historical perspective on advances in H. jecorina molecular biology, 2) outline host strain engineering, transformation, selection, and expression strategies, 3) detail potential pitfalls when working with this organism, and 4) provide consolidated examples of successful cellulase expression outcomes from our laboratory.
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Huang Y, Busk PK, Grell MN, Zhao H, Lange L. Identification of a β-glucosidase from the Mucor circinelloides genome by peptide pattern recognition. Enzyme Microb Technol 2014; 67:47-52. [DOI: 10.1016/j.enzmictec.2014.09.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 08/29/2014] [Accepted: 09/03/2014] [Indexed: 11/26/2022]
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Kinetic Characterization and Effect of Immobilized Thermostable β-Glucosidase in Alginate Gel Beads on Sugarcane Juice. ISRN BIOCHEMISTRY 2014; 2014:178498. [PMID: 25969764 PMCID: PMC4392994 DOI: 10.1155/2014/178498] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Accepted: 12/16/2013] [Indexed: 11/18/2022]
Abstract
A thermostable β-glucosidase was effectively immobilized on alginate by the method of gel entrapment. After optimization of immobilized conditions, recovered enzyme activity was 60%. Optimum pH, temperature, kinetic parameters, thermal and pH stability, reusability, and storage stability were investigated. The K m and V max for immobilized β-glucosidase were estimated to be 5.0 mM and 0.64 U/ml, respectively. When comparing, free and immobilized enzyme, change was observed in optimum pH and temperature from 5.0 to 6.0 and 60°C to 80°C, respectively. Immobilized enzyme showed an increase in pH stability over the studied pH range (3.0-10.0) and stability at temperature up to 80°C. The storage stability and reusability of the immobilized β-glucosidase were improved significantly, with 12.09% activity retention at 30°C after being stored for 25 d and 17.85% residual activity after being repeatedly used for 4 times. The effect of both free and immobilized β-glucosidase enzyme on physicochemical properties of sugarcane juice was also analyzed.
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Gong Z, Wang Q, Shen H, Wang L, Xie H, Zhao ZK. Conversion of biomass-derived oligosaccharides into lipids. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:13. [PMID: 24472330 PMCID: PMC3927853 DOI: 10.1186/1754-6834-7-13] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 01/15/2014] [Indexed: 05/18/2023]
Abstract
BACKGROUND Oligocelluloses and oligoxyloses are partially hydrolyzed products from lignocellulosic biomass hydrolysis. Biomass hydrolysates usually contain monosaccharides as well as various amounts of oligosaccharides. To utilize biomass hydrolysates more efficiently, it is important to identify microorganisms capable of converting biomass-derived oligosaccharides into biofuels or biochemicals. RESULTS We have demonstrated that the oleaginous yeast Cryptococcus curvatus can utilize either oligocelluloses or oligoxyloses as sole carbon sources for microbial lipid production. When oligocelluloses were used, lipid content and lipid coefficient were 35.9% and 0.20 g/g consumed sugar, respectively. When oligoxyloses were used, lipid coefficient was 0.17 g/g consumed sugar. Ion chromatography analysis showed oligocelluloses with a degree of polymerization from 2 to 9 were assimilated. Our data suggested that these oligosaccharides were transported into cells and then hydrolyzed by cytoplasmic enzymes. Further analysis indicated that these enzymes were inducible by oligocelluloses. Lipid production on cellulose by C. curvatus using the simultaneous saccharification and lipid production process in the absence of cellobiase achieved essentially identical results to that in the presence of cellobiase, suggesting that oligocelluloses generated in situ were utilized with high efficiency. This study has provided inspiring information for oligosaccharides utilization, which should facilitate biorefinery based on lignocellulosic biomass. CONCLUSIONS C. curvatus can directly utilize biomass-derived oligosaccharides. Oligocelluloses are transported into the cells and then hydrolyzed by cytoplasmic enzymes. A simultaneous saccharification and lipid production process can be conducted without oligocelluloses accumulation in the absence of cellobiase by C. curvatus, which could reduce the enzyme costs.
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Affiliation(s)
- Zhiwei Gong
- Dalian National Laboratory for Clean Energy and Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian 116023, PR China
- University of the Chinese Academy of Sciences, Beijing 100049, PR China
| | - Qian Wang
- Dalian National Laboratory for Clean Energy and Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian 116023, PR China
| | - Hongwei Shen
- Dalian National Laboratory for Clean Energy and Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian 116023, PR China
| | - Lei Wang
- Dalian National Laboratory for Clean Energy and Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian 116023, PR China
| | - Haibo Xie
- Dalian National Laboratory for Clean Energy and Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian 116023, PR China
| | - Zongbao K Zhao
- Dalian National Laboratory for Clean Energy and Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian 116023, PR China
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Adrio JL, Demain AL. Microbial enzymes: tools for biotechnological processes. Biomolecules 2014; 4:117-39. [PMID: 24970208 PMCID: PMC4030981 DOI: 10.3390/biom4010117] [Citation(s) in RCA: 283] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 01/02/2014] [Accepted: 01/02/2014] [Indexed: 11/29/2022] Open
Abstract
Microbial enzymes are of great importance in the development of industrial bioprocesses. Current applications are focused on many different markets including pulp and paper, leather, detergents and textiles, pharmaceuticals, chemical, food and beverages, biofuels, animal feed and personal care, among others. Today there is a need for new, improved or/and more versatile enzymes in order to develop more novel, sustainable and economically competitive production processes. Microbial diversity and modern molecular techniques, such as metagenomics and genomics, are being used to discover new microbial enzymes whose catalytic properties can be improved/modified by different strategies based on rational, semi-rational and random directed evolution. Most industrial enzymes are recombinant forms produced in bacteria and fungi.
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Affiliation(s)
- Jose L Adrio
- Neol Biosolutions SA, BIC Granada, Granada 18016, Spain.
| | - Arnold L Demain
- Research Institute for Scientists Emeriti (R.I.S.E.), Drew University, Madison, NJ 07940, USA.
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Garvey M, Klose H, Fischer R, Lambertz C, Commandeur U. Cellulases for biomass degradation: comparing recombinant cellulase expression platforms. Trends Biotechnol 2013; 31:581-93. [DOI: 10.1016/j.tibtech.2013.06.006] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 06/21/2013] [Accepted: 06/24/2013] [Indexed: 10/26/2022]
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β -Glucosidases from the fungus trichoderma: an efficient cellulase machinery in biotechnological applications. BIOMED RESEARCH INTERNATIONAL 2013; 2013:203735. [PMID: 23984325 PMCID: PMC3747355 DOI: 10.1155/2013/203735] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 06/15/2013] [Indexed: 11/17/2022]
Abstract
β-glucosidases catalyze the selective cleavage of glucosidic linkages and are an important class of enzymes having significant prospects in industrial biotechnology. These are classified in family 1 and family 3 of glycosyl hydrolase family. β-glucosidases, particularly from the fungus Trichoderma, are widely recognized and used for the saccharification of cellulosic biomass for biofuel production. With the rising trends in energy crisis and depletion of fossil fuels, alternative strategies for renewable energy sources need to be developed. However, the major limitation accounts for low production of β-glucosidases by the hyper secretory strains of Trichoderma. In accordance with the increasing significance of β-glucosidases in commercial applications, the present review provides a detailed insight of the enzyme family, their classification, structural parameters, properties, and studies at the genomics and proteomics levels. Furthermore, the paper discusses the enhancement strategies employed for their utilization in biofuel generation. Therefore, β-glucosidases are prospective toolbox in bioethanol production, and in the near future, it might be successful in meeting the requirements of alternative renewable sources of energy.
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Jourdier E, Cohen C, Poughon L, Larroche C, Monot F, Chaabane FB. Cellulase activity mapping of Trichoderma reesei cultivated in sugar mixtures under fed-batch conditions. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:79. [PMID: 23680258 PMCID: PMC3700819 DOI: 10.1186/1754-6834-6-79] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 05/15/2013] [Indexed: 05/02/2023]
Abstract
BACKGROUND On-site cellulase production using locally available lignocellulosic biomass (LCB) is essential for cost-effective production of 2nd-generation biofuels. Cellulolytic enzymes (cellulases and hemicellulases) must be produced in fed-batch mode in order to obtain high productivity and yield. To date, the impact of the sugar composition of LCB hydrolysates on cellulolytic enzyme secretion has not been thoroughly investigated in industrial conditions. RESULTS The effect of sugar mixtures (glucose, xylose, inducer) on the secretion of cellulolytic enzymes by a glucose-derepressed and cellulase-hyperproducing mutant strain of Trichoderma reesei (strain CL847) was studied using a small-scale protocol representative of the industrial conditions. Since production of cellulolytic enzymes is inducible by either lactose or cellobiose, two parallel mixture designs were performed separately. No significant difference between inducers was observed on cellulase secretion performance, probably because a common induction mechanism occurred under carbon flux limitation. The characteristics of the enzymatic cocktails did not correlate with productivity, but instead were rather dependent on the substrate composition. Increasing xylose content in the feed had the strongest impact. It decreased by 2-fold cellulase, endoglucanase, and cellobiohydrolase activities and by 4-fold β-glucosidase activity. In contrast, xylanase activity was increased 6-fold. Accordingly, simultaneous high β-glucosidase and xylanase activities in the enzymatic cocktails seemed to be incompatible. The variations in enzymatic activity were modelled and validated with four fed-batch cultures performed in bioreactors. The overall enzyme production was maintained at its highest level when substituting up to 75% of the inducer with non-inducing sugars. CONCLUSIONS The sugar substrate composition strongly influenced the composition of the cellulolytic cocktail secreted by T. reesei in fed-batch mode. Modelling can be used to predict cellulolytic activity based on the sugar composition of the culture-feeding solution, or to fine tune the substrate composition in order to produce a desired enzymatic cocktail.
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Affiliation(s)
- Etienne Jourdier
- IFP Energies nouvelles, 1 et 4 avenue de Bois-Préau, 92852 Rueil-Malmaison, France
| | - Céline Cohen
- IFP Energies nouvelles, 1 et 4 avenue de Bois-Préau, 92852 Rueil-Malmaison, France
| | - Laurent Poughon
- Clermont Université, Université Blaise Pascal, Labex IMobS3, Institut Pascal, Polytech Clermont-Ferrand, 24 av. des Landais, BP 20206, 63174 Aubière cedex, France
| | - Christian Larroche
- Clermont Université, Université Blaise Pascal, Labex IMobS3, Institut Pascal, Polytech Clermont-Ferrand, 24 av. des Landais, BP 20206, 63174 Aubière cedex, France
| | - Frédéric Monot
- IFP Energies nouvelles, 1 et 4 avenue de Bois-Préau, 92852 Rueil-Malmaison, France
| | - Fadhel Ben Chaabane
- IFP Energies nouvelles, 1 et 4 avenue de Bois-Préau, 92852 Rueil-Malmaison, France
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