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Yang W, Su Y, Wang R, Zhang H, Jing H, Meng J, Zhang G, Huang L, Guo L, Wang J, Gao W. Microbial production and applications of β-glucosidase-A review. Int J Biol Macromol 2024; 256:127915. [PMID: 37939774 DOI: 10.1016/j.ijbiomac.2023.127915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 10/03/2023] [Accepted: 11/04/2023] [Indexed: 11/10/2023]
Abstract
β-Glucosidase exists in all areas of living organisms, and microbial β-glucosidase has become the main source of its production because of its unique physicochemical properties and the advantages of high-yield production by fermentation. With the rise of the green circular economy, the production of enzymes through the fermentation of waste as the substrate has become a popular trend. Lignocellulosic biomass is an easily accessible and sustainable feedstock that exists in nature, and the production of biofuels from lignocellulosic biomass requires the involvement of β-glucosidase. This review proposes ways to improve β-glucosidase yield and catalytic efficiency. Optimization of growth conditions and purification strategies of enzymes can increase enzyme yield, and enzyme immobilization, genetic engineering, protein engineering, and whole-cell catalysis provide solutions to enhance the catalytic efficiency and activity of β-glucosidase. Besides, the diversified industrial applications, challenges and prospects of β-glucosidase are also described.
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Affiliation(s)
- Wenqi Yang
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China; Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, China
| | - Yaowu Su
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China; Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, China
| | - Rubing Wang
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China; Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, China
| | - Huanyu Zhang
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China; Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, China
| | - Hongyan Jing
- Traditional Chinese Medicine College, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Jie Meng
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China; Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, China
| | - Guoqi Zhang
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China; Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, China
| | - Luqi Huang
- National Resource Center for Chinese Meteria Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China
| | - Lanping Guo
- National Resource Center for Chinese Meteria Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China; State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs.
| | - Juan Wang
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China; Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, China.
| | - Wenyuan Gao
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China; Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, China.
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Chaudhari YB, Várnai A, Sørlie M, Horn SJ, Eijsink VGH. Engineering cellulases for conversion of lignocellulosic biomass. Protein Eng Des Sel 2023; 36:gzad002. [PMID: 36892404 PMCID: PMC10394125 DOI: 10.1093/protein/gzad002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 02/13/2023] [Accepted: 02/24/2023] [Indexed: 03/10/2023] Open
Abstract
Lignocellulosic biomass is a renewable source of energy, chemicals and materials. Many applications of this resource require the depolymerization of one or more of its polymeric constituents. Efficient enzymatic depolymerization of cellulose to glucose by cellulases and accessory enzymes such as lytic polysaccharide monooxygenases is a prerequisite for economically viable exploitation of this biomass. Microbes produce a remarkably diverse range of cellulases, which consist of glycoside hydrolase (GH) catalytic domains and, although not in all cases, substrate-binding carbohydrate-binding modules (CBMs). As enzymes are a considerable cost factor, there is great interest in finding or engineering improved and robust cellulases, with higher activity and stability, easy expression, and minimal product inhibition. This review addresses relevant engineering targets for cellulases, discusses a few notable cellulase engineering studies of the past decades and provides an overview of recent work in the field.
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Affiliation(s)
- Yogesh B Chaudhari
- Faculty of Chemistry, Biotechnology, and Food Science, NMBU-Norwegian University of Life Sciences, P.O. Box 5003, 1432 Ås, Norway
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology, and Food Science, NMBU-Norwegian University of Life Sciences, P.O. Box 5003, 1432 Ås, Norway
| | - Morten Sørlie
- Faculty of Chemistry, Biotechnology, and Food Science, NMBU-Norwegian University of Life Sciences, P.O. Box 5003, 1432 Ås, Norway
| | - Svein J Horn
- Faculty of Chemistry, Biotechnology, and Food Science, NMBU-Norwegian University of Life Sciences, P.O. Box 5003, 1432 Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology, and Food Science, NMBU-Norwegian University of Life Sciences, P.O. Box 5003, 1432 Ås, Norway
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Xia W, Bai Y, Shi P. Improving the Substrate Affinity and Catalytic Efficiency of β-Glucosidase Bgl3A from Talaromyces leycettanus JCM12802 by Rational Design. Biomolecules 2021; 11:biom11121882. [PMID: 34944526 PMCID: PMC8699594 DOI: 10.3390/biom11121882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 12/08/2021] [Accepted: 12/09/2021] [Indexed: 12/31/2022] Open
Abstract
Improving the substrate affinity and catalytic efficiency of β-glucosidase is necessary for better performance in the enzymatic saccharification of cellulosic biomass because of its ability to prevent cellobiose inhibition on cellulases. Bgl3A from Talaromyces leycettanus JCM12802, identified in our previous work, was considered a suitable candidate enzyme for efficient cellulose saccharification with higher catalytic efficiency on the natural substrate cellobiose compared with other β-glucosidase but showed insufficient substrate affinity. In this work, hydrophobic stacking interaction and hydrogen-bonding networks in the active center of Bgl3A were analyzed and rationally designed to strengthen substrate binding. Three vital residues, Met36, Phe66, and Glu168, which were supposed to influence substrate binding by stabilizing adjacent binding site, were chosen for mutagenesis. The results indicated that strengthening the hydrophobic interaction between stacking aromatic residue and the substrate, and stabilizing the hydrogen-bonding networks in the binding pocket could contribute to the stabilized substrate combination. Four dominant mutants, M36E, M36N, F66Y, and E168Q with significantly lower Km values and 1.4–2.3-fold catalytic efficiencies, were obtained. These findings may provide a valuable reference for the design of other β-glucosidases and even glycoside hydrolases.
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Affiliation(s)
- Wei Xia
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100081, China;
| | - Yingguo Bai
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- Correspondence: (Y.B.); (P.S.)
| | - Pengjun Shi
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100081, China;
- Correspondence: (Y.B.); (P.S.)
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Fungal cellulases: protein engineering and post-translational modifications. Appl Microbiol Biotechnol 2021; 106:1-24. [PMID: 34889986 DOI: 10.1007/s00253-021-11723-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 11/28/2021] [Accepted: 11/30/2021] [Indexed: 12/18/2022]
Abstract
Enzymatic degradation of lignocelluloses into fermentable sugars to produce biofuels and other biomaterials is critical for environmentally sustainable development and energy resource supply. However, there are problems in enzymatic cellulose hydrolysis, such as the complex cellulase composition, low degradation efficiency, high production cost, and post-translational modifications (PTMs), all of which are closely related to specific characteristics of cellulases that remain unclear. These problems hinder the practical application of cellulases. Due to the rapid development of computer technology in recent years, computer-aided protein engineering is being widely used, which also brings new opportunities for the development of cellulases. Especially in recent years, a large number of studies have reported on the application of computer-aided protein engineering in the development of cellulases; however, these articles have not been systematically reviewed. This article focused on the aspect of protein engineering and PTMs of fungal cellulases. In this manuscript, the latest literatures and the distribution of potential sites of cellulases for engineering have been systematically summarized, which provide reference for further improvement of cellulase properties. KEY POINTS: •Rational design based on virtual mutagenesis can improve cellulase properties. •Modifying protein side chains and glycans helps obtain superior cellulases. •N-terminal glutamine-pyroglutamate conversion stabilizes fungal cellulases.
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Kao MR, Yu SM, Ho THUD. Improvements of the productivity and saccharification efficiency of the cellulolytic β-glucosidase D2-BGL in Pichia pastoris via directed evolution. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:126. [PMID: 34059121 PMCID: PMC8166090 DOI: 10.1186/s13068-021-01973-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 05/17/2021] [Indexed: 05/02/2023]
Abstract
BACKGROUND β-Glucosidases are essential for cellulose hydrolysis by catalyzing the final cellulolytic degradation of cello-oligomers and cellobiose to glucose. D2-BGL is a fungal glycoside hydrolase family 3 (GH3) β-glucosidase isolated from Chaetomella raphigera with high substrate affinity, and is an efficient β-glucosidase supplement to Trichoderma reesei cellulase mixtures for the saccharification of lignocellulosic biomass. RESULTS We have carried out error-prone PCR to further increase catalytic efficiency of wild-type (WT) D2-BGL. Three mutants, each with substitution of two amino acids on D2-BGL, exhibited increased activity in a preliminary mutant screening in Saccharomyces cerevisiae. Effects of single amino acid replacements on catalysis efficiency and enzyme production have been investigated by subsequent expression in Pichia pastoris. Substitution F256M resulted in enhancing the tolerance to substrate inhibition and specific activity, and substitution D224G resulted in increasing the production of recombinant enzyme. The best D2-BGL mutant generated, Mut M, was constructed by combining beneficial mutations D224G, F256M and Y260D. Expression of Mut M in Pichia pastoris resulted in 2.7-fold higher production of recombinant protein, higher Vmax and greater substrate inhibition tolerance towards cellobiose relative to wild-type enzyme. Surprisingly, Mut M overexpression induced the ER unfolded protein response to a level lower than that with WT D2 overexpression in P. pastoris. When combined with the T. reesei cellulase preparation Celluclast 1.5L, Mut M hydrolyzed acid-pretreated sugarcane bagasse more efficiently than WT D2. CONCLUSIONS D2-BGL mutant Mut M was generated successfully by following directed evolution approach. Mut M carries three mutations that are not reported in other directed evolution studies of GH3 β-glucosidases, and this mutant exhibited greater tolerance to substrate inhibition and higher Vmax than wild-type enzyme. Besides the enhanced specific activity, Mut M also exhibited a higher protein titer than WT D2 when it was overexpressed in P. pastoris. Our study demonstrates that both catalytic efficiency and productivity of a cellulolytic enzyme can be enhanced via protein engineering.
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Affiliation(s)
- Mu-Rong Kao
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and National Defense Medical Center, Taipei, 115 Taiwan
- Institute of Molecular Biology, Academia Sinica, Taipei, 115 Taiwan
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 115 Taiwan
| | - Su-May Yu
- Institute of Molecular Biology, Academia Sinica, Taipei, 115 Taiwan
- Department of Plant Pathology, National Chung Hsing University, Taichung, 402 Taiwan
- Department of Life Sciences, National Chung Hsing University, Taichung, 402 Taiwan
- Biotechnology Center, National Chung Hsing University, Taichung, 402 Taiwan
| | - Tuan-H ua David Ho
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 115 Taiwan
- Biotechnology Center, National Chung Hsing University, Taichung, 402 Taiwan
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Madhavan A, Arun KB, Binod P, Sirohi R, Tarafdar A, Reshmy R, Kumar Awasthi M, Sindhu R. Design of novel enzyme biocatalysts for industrial bioprocess: Harnessing the power of protein engineering, high throughput screening and synthetic biology. BIORESOURCE TECHNOLOGY 2021; 325:124617. [PMID: 33450638 DOI: 10.1016/j.biortech.2020.124617] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/19/2020] [Accepted: 12/22/2020] [Indexed: 05/13/2023]
Abstract
Biocatalysts have wider applications in various industries. Biocatalysts are generating bigger attention among researchers due to their unique catalytic properties like activity, specificity and stability. However the industrial use of many enzymes is hindered by low catalytic efficiency and stability during industrial processes. Properties of enzymes can be altered by protein engineering. Protein engineers are increasingly study the structure-function characteristics, engineering attributes, design of computational tools for enzyme engineering, and functional screening processes to improve the design and applications of enzymes. The potent and innovative techniques of enzyme engineering deliver outstanding opportunities for tailoring industrially important enzymes for the versatile production of biochemicals. An overview of the current trends in enzyme engineering is explored with important representative examples.
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Affiliation(s)
- Aravind Madhavan
- Rajiv Gandhi Centre for Biotechnology, Trivandrum 695 014, India
| | - K B Arun
- Rajiv Gandhi Centre for Biotechnology, Trivandrum 695 014, India
| | - Parameswaran Binod
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Trivandrum 695 019, India
| | - Ranjna Sirohi
- The Center for Energy and Environmental Sustainability, Lucknow 226 010, Uttar Pradesh, India
| | - Ayon Tarafdar
- Division of Livestock Production and Management, ICAR - Indian Veterinary Research Institute, Izatnagar, Bareilly 243 122, Uttar Pradesh, India
| | - R Reshmy
- Post Graduate and Research Department of Chemistry, Bishop Moore College, Mavelikara 690 110, Kerala, India
| | - Mukesh Kumar Awasthi
- College of Natural Resources and Environment, North West A & F University, Yangling, Shaanxi 712 100, China
| | - Raveendran Sindhu
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Trivandrum 695 019, India.
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Contreras F, Pramanik S, M. Rozhkova A, N. Zorov I, Korotkova O, P. Sinitsyn A, Schwaneberg U, D. Davari M. Engineering Robust Cellulases for Tailored Lignocellulosic Degradation Cocktails. Int J Mol Sci 2020; 21:E1589. [PMID: 32111065 PMCID: PMC7084875 DOI: 10.3390/ijms21051589] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/21/2020] [Accepted: 02/24/2020] [Indexed: 12/11/2022] Open
Abstract
Lignocellulosic biomass is a most promising feedstock in the production of second-generation biofuels. Efficient degradation of lignocellulosic biomass requires a synergistic action of several cellulases and hemicellulases. Cellulases depolymerize cellulose, the main polymer of the lignocellulosic biomass, to its building blocks. The production of cellulase cocktails has been widely explored, however, there are still some main challenges that enzymes need to overcome in order to develop a sustainable production of bioethanol. The main challenges include low activity, product inhibition, and the need to perform fine-tuning of a cellulase cocktail for each type of biomass. Protein engineering and directed evolution are powerful technologies to improve enzyme properties such as increased activity, decreased product inhibition, increased thermal stability, improved performance in non-conventional media, and pH stability, which will lead to a production of more efficient cocktails. In this review, we focus on recent advances in cellulase cocktail production, its current challenges, protein engineering as an efficient strategy to engineer cellulases, and our view on future prospects in the generation of tailored cellulases for biofuel production.
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Affiliation(s)
- Francisca Contreras
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
| | - Subrata Pramanik
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
| | - Aleksandra M. Rozhkova
- Federal Research Centre «Fundamentals of Biotechnology» of the Russian Academy of Sciences, 119071 Moscow, Russia
- Department of Chemistry, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Ivan N. Zorov
- Federal Research Centre «Fundamentals of Biotechnology» of the Russian Academy of Sciences, 119071 Moscow, Russia
- Department of Chemistry, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Olga Korotkova
- Federal Research Centre «Fundamentals of Biotechnology» of the Russian Academy of Sciences, 119071 Moscow, Russia
| | - Arkady P. Sinitsyn
- Federal Research Centre «Fundamentals of Biotechnology» of the Russian Academy of Sciences, 119071 Moscow, Russia
- Department of Chemistry, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Ulrich Schwaneberg
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
- DWI-Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52074 Aachen, Germany
| | - Mehdi D. Davari
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
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Chen Z, Liu Y, Liu L, Chen Y, Li S, Jia Y. Purification and characterization of a novel β-glucosidase from Aspergillus flavus and its application in saccharification of soybean meal. Prep Biochem Biotechnol 2019; 49:671-678. [PMID: 30990111 DOI: 10.1080/10826068.2019.1599397] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Aspergillus flavus has been regarded as a potential candidate for its production of industrial enzymes, but the details of β-glucosidase from this strain is very limited. In herein, we first reported a novel β-glucosidase (AfBglA) with the molecular mass of 94.2 kDa from A. flavus. AfBglA was optimally active at pH 4.5 and 60 °C and is stable between pH 3.5 and 9.0 and at a temperature of up to 55 °C for 30 min remaining more than 90% of its initial activity. It showed an excellent tolerance to Trypsin, Pepsin, Compound Protease, and Flavourzyme and its activity was not inhibited by specific certain cations. AfBglA displayed broad substrate specificity, it acted on all tested pNP-glycosides and barley glucan, indicating this novel β-glucosidase exhibited a β-1, 3-1, 4-glucanase activity. Moreover, the AfBglA could effectively hydrolyze the soybean meal suspension into glucose and exhibit a strong tolerance to the inhibition of glucose at a concentration of 20.0 g/L during the saccharification. The maximum amount of the glucose obtained by AfBglA corresponded to 67.0 g/kg soybean meal. All of these properties mentioned above indicated that the AfBglA possibly attractive for food and feed industry and saccharification of cellulolytic materials.
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Affiliation(s)
- Zhou Chen
- a Lab of Enzyme Engineering, School of Food and Chemical Engineering , Beijing Technology and Business University , Beijing , China
| | - Yangliu Liu
- a Lab of Enzyme Engineering, School of Food and Chemical Engineering , Beijing Technology and Business University , Beijing , China
| | - Lu Liu
- a Lab of Enzyme Engineering, School of Food and Chemical Engineering , Beijing Technology and Business University , Beijing , China
| | - Yaoyao Chen
- a Lab of Enzyme Engineering, School of Food and Chemical Engineering , Beijing Technology and Business University , Beijing , China
| | - Siting Li
- a Lab of Enzyme Engineering, School of Food and Chemical Engineering , Beijing Technology and Business University , Beijing , China
| | - Yingmin Jia
- a Lab of Enzyme Engineering, School of Food and Chemical Engineering , Beijing Technology and Business University , Beijing , China
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Kao MR, Kuo HW, Lee CC, Huang KY, Huang TY, Li CW, Chen CW, Wang AHJ, Yu SM, Ho THD. Chaetomella raphigera β-glucosidase D2-BGL has intriguing structural features and a high substrate affinity that renders it an efficient cellulase supplement for lignocellulosic biomass hydrolysis. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:258. [PMID: 31700541 PMCID: PMC6825360 DOI: 10.1186/s13068-019-1599-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 10/22/2019] [Indexed: 05/17/2023]
Abstract
BACKGROUND To produce second-generation biofuels, enzymatic catalysis is required to convert cellulose from lignocellulosic biomass into fermentable sugars. β-Glucosidases finalize the process by hydrolyzing cellobiose into glucose, so the efficiency of cellulose hydrolysis largely depends on the quantity and quality of these enzymes used during saccharification. Accordingly, to reduce biofuel production costs, new microbial strains are needed that can produce highly efficient enzymes on a large scale. RESULTS We heterologously expressed the fungal β-glucosidase D2-BGL from a Taiwanese indigenous fungus Chaetomella raphigera in Pichia pastoris for constitutive production by fermentation. Recombinant D2-BGL presented significantly higher substrate affinity than the commercial β-glucosidase Novozyme 188 (N188; K m = 0.2 vs 2.14 mM for p-nitrophenyl β-d-glucopyranoside and 0.96 vs 2.38 mM for cellobiose). When combined with RUT-C30 cellulases, it hydrolyzed acid-pretreated lignocellulosic biomasses more efficiently than the commercial cellulase mixture CTec3. The extent of conversion from cellulose to glucose was 83% for sugarcane bagasse and 63% for rice straws. Compared to N188, use of D2-BGL halved the time necessary to produce maximal levels of ethanol by a semi-simultaneous saccharification and fermentation process. We upscaled production of recombinant D2-BGL to 33.6 U/mL within 15 days using a 1-ton bioreactor. Crystal structure analysis revealed that D2-BGL belongs to glycoside hydrolase (GH) family 3. Removing the N-glycosylation N68 or O-glycosylation T431 residues by site-directed mutagenesis negatively affected enzyme production in P. pastoris. The F256 substrate-binding residue in D2-BGL is located in a shorter loop surrounding the active site pocket relative to that of Aspergillus β-glucosidases, and this short loop is responsible for its high substrate affinity toward cellobiose. CONCLUSIONS D2-BGL is an efficient supplement for lignocellulosic biomass saccharification, and we upscaled production of this enzyme using a 1-ton bioreactor. Enzyme production could be further improved using optimized fermentation, which could reduce biofuel production costs. Our structure analysis of D2-BGL offers new insights into GH3 β-glucosidases, which will be useful for strain improvements via a structure-based mutagenesis approach.
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Affiliation(s)
- Mu-Rong Kao
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and National Defense Medical Center, Taipei, Taiwan, ROC
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Hsion-Wen Kuo
- Department of Environmental Science and Engineering, Tunghai University, Taichung, Taiwan, ROC
| | - Cheng-Chung Lee
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, ROC
| | - Kuan-Ying Huang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Ting-Yen Huang
- Department of Bioengineering, Tatung University, Taipei, Taiwan, ROC
| | - Chen-Wei Li
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - C. Will Chen
- Department of Bioengineering, Tatung University, Taipei, Taiwan, ROC
| | | | - Su-May Yu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
- Biotechnology Center, National Chung Hsing University, Taichung, Taiwan, ROC
| | - Tuan-Hua David Ho
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, ROC
- Biotechnology Center, National Chung Hsing University, Taichung, Taiwan, ROC
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