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Minnaar L, den Haan R. Engineering natural isolates of Saccharomyces cerevisiae for consolidated bioprocessing of cellulosic feedstocks. Appl Microbiol Biotechnol 2023; 107:7013-7028. [PMID: 37688599 PMCID: PMC10589140 DOI: 10.1007/s00253-023-12729-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/03/2023] [Accepted: 08/06/2023] [Indexed: 09/11/2023]
Abstract
Saccharomyces cerevisiae has gained much attention as a potential host for cellulosic bioethanol production using consolidated bioprocessing (CBP) methodologies, due to its high-ethanol-producing titres, heterologous protein production capabilities, and tolerance to various industry-relevant stresses. Since the secretion levels of heterologous proteins are generally low in domesticated strains of S. cerevisiae, natural isolates may offer a more diverse genetic background for improved heterologous protein secretion, while also displaying greater robustness to process stresses. In this study, the potential of natural and industrial S. cerevisiae strains to secrete a core set of cellulases (CBH1, CBH2, EG2, and BGL1), encoded by genes integrated using CRISPR/Cas9 tools, was evaluated. High levels of heterologous protein production were associated with a reduced maximal growth rate and with slight changes in overall strain robustness, compared to the parental strains. The natural isolate derivatives YI13_BECC and YI59_BECC displayed superior secretion capacity for the heterologous cellulases at high incubation temperature and in the presence of acetic acid, respectively, compared to the reference industrial strain MH1000_BECC. These strains also exhibited multi-tolerance to several fermentation-associated and secretion stresses. Cultivation of the strains on crystalline cellulose in oxygen-limited conditions yielded ethanol concentrations in the range of 4-4.5 g/L, representing 35-40% of the theoretical maximum ethanol yield after 120 h, without the addition of exogenous enzymes. This study therefore highlights the potential of these natural isolates to be used as chassis organisms in CBP bioethanol production. KEY POINTS: • Process-related fermentation stresses influence heterologous protein production. • Transformants produced up to 4.5 g/L ethanol, ~ 40% of the theoretical yield in CBP. • CRISPR/Cas9 was feasible for integrating genes in natural S. cerevisiae isolates.
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Affiliation(s)
- Letitia Minnaar
- Department of Biotechnology, University of the Western Cape, Bellville, South Africa
| | - Riaan den Haan
- Department of Biotechnology, University of the Western Cape, Bellville, South Africa.
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Singh R, Saati AA, Faidah H, Bantun F, Jalal NA, Haque S, Rai AK, Srivastava M. Prospects of microbial cellulase production using banana peels wastes for antimicrobial applications. Int J Food Microbiol 2023; 388:110069. [PMID: 36640563 DOI: 10.1016/j.ijfoodmicro.2022.110069] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 11/14/2022] [Accepted: 12/27/2022] [Indexed: 01/01/2023]
Abstract
Microorganisms have been extensively studied and used to produce a wide range of enzymes and bioactive substances for a number of uses. Cellulases have also been widely used for a variety of bioprocessing and biotransformation purposes and are acknowledged as the essential enzymes for industrial applications. Broad industrial applications and huge demand essentially require mass-scale and low-cost production of cellulase enzyme. Nevertheless, low-cost production of cellulase enzyme at industrial-level finds certain issues, and this may be mainly associated with the unavailability of cheap and effective substrate to be utilized in fermentation process. In this context, cellulosic wastes are counted as one of the suitable bioresources and have been well explored for low-cost and highly efficient cellulase enzyme productions. Further, banana peels waste is considered as the high cellulose & sugar containing food wastes which is renewable and hugely available worldwide. Therefore, the present review explores the possible utilizations of banana peels as a potential food waste to be employed as substrate to produce cellulase enzymes. Availability and compositional analysis of banana peels has been explored for the microbial cellulase production based on reported studies. Further, this review explores the applications of cellulase enzymes as antimicrobial agents. Based on the available studies and their evaluation, potential limitations and future suggestions for the production of cellulase enzymes and their applications as antibacterial agents have been provided, which have a high potential for numerous biomedical applications and may offer a new opportunity for industrial utility.
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Affiliation(s)
- Rajeev Singh
- Department of Environmental Studies, Satyawati College, University of Delhi, Delhi 110052, India; Department of Environmental Science, Jamia Millia Islamia, (A Central University), New Delhi 110025, India
| | - Abdullah Ali Saati
- Department of Community Medicine & Pilgrims Healthcare, Faculty of Medicine, Umm Al-Qura University, Saudi Arabia
| | - Hani Faidah
- Department of Microbiology, Faculty of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Farkad Bantun
- Department of Microbiology, Faculty of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Naif A Jalal
- Department of Microbiology, Faculty of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Shafiul Haque
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan 45142, Saudi Arabia; Centre of Medical and Bio-Allied Health Sciences Research, Ajman University, Ajman, United Arab Emirates
| | - Ashutosh Kumar Rai
- Department of Biochemistry, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Manish Srivastava
- Department of Chemical Engineering and Technology, Indian Institute of Technology (BHU), Varanasi, Varanasi 221005, India; LCB Fertilizers Pvt. Ltd., Shyam Vihar Phase 2, Rani Sati Mandir Road, Lachchhipur, Gorakhpur, Uttar Pradesh-273015, India.
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Chetty BJ, Inokuma K, Hasunuma T, van Zyl WH, den Haan R. Improvement of cell-tethered cellulase activity in recombinant strains of Saccharomyces cerevisiae. Appl Microbiol Biotechnol 2022; 106:6347-6361. [PMID: 35951080 DOI: 10.1007/s00253-022-12114-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/27/2022] [Accepted: 07/28/2022] [Indexed: 11/30/2022]
Abstract
Consolidated bioprocessing (CBP) remains an attractive option for the production of commodity products from pretreated lignocellulose if a process-suitable organism can be engineered. The yeast Saccharomyces cerevisiae requires engineered cellulolytic activity to enable its use in CBP production of second-generation (2G) bioethanol. A promising strategy for heterologous cellulase production in yeast entails displaying enzymes on the cell surface by means of glycosylphosphatidylinositol (GPI) anchors. While strains producing a core set of cell-adhered cellulases that enabled crystalline cellulose hydrolysis have been created, secreted levels of enzyme were insufficient for complete cellulose hydrolysis. In fact, all reported recombinant yeast CBP candidates must overcome the drawback of generally low secretion titers. Rational strain engineering can be applied to enhance the secretion phenotype. This study aimed to improve the amount of cell-adhered cellulase activities of recombinant S. cerevisiae strains expressing a core set of four cellulases, through overexpression of genes that were previously shown to enhance cellulase secretion. Results showed significant increases in cellulolytic activity for all cell-adhered cellulase enzyme types. Cell-adhered cellobiohydrolase activity was improved by up to 101%, β-glucosidase activity by up to 99%, and endoglucanase activity by up to 231%. Improved hydrolysis of crystalline cellulose of up to 186% and improved ethanol yields from this substrate of 40-50% in different strain backgrounds were also observed. In addition, improvement in resistance to fermentation stressors was noted in some strains. These strains represent a step towards more efficient organisms for use in 2G biofuel production. KEY POINTS: • Cell-surface-adhered cellulase activity was improved in strains engineered for CBP. • Levels of improvement of activity were strain and enzyme dependent. • Crystalline cellulose conversion to ethanol could be improved up to 50%.
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Affiliation(s)
- Bronwyn Jean Chetty
- Department of Biotechnology, University of the Western Cape, Bellville, South Africa
| | - Kentaro Inokuma
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, 657-8501, Japan
| | - Tomohisa Hasunuma
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, 657-8501, Japan
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, 657-8501, Japan
| | | | - Riaan den Haan
- Department of Biotechnology, University of the Western Cape, Bellville, South Africa.
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Tan Y, Stein LY, Sauvageau D. The influence of self-cycling fermentation long- and short-cycle schemes on Saccharomyces cerevisiae and Escherichia coli. Sci Rep 2022; 12:13154. [PMID: 35915208 PMCID: PMC9343364 DOI: 10.1038/s41598-022-16831-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 07/18/2022] [Indexed: 11/09/2022] Open
Abstract
Self-cycling fermentation (SCF), a cyclic process in which cells, on average, divide once per cycle, has been shown to lead to whole-culture synchronization and improvements in productivity during bioconversion. Previous studies have shown that the completion of synchronized cell replication sometimes occurs simultaneously with depletion of the limiting nutrient. However, cases in which the end of cell doubling occurred before limiting nutrient exhaustion were also observed. In order to better understand the impact of these patterns on bioprocessing, we investigated the growth of Saccharomyces cerevisiae and Escherichia coli in long- and short-cycle SCF strategies. Three characteristic events were identified during SCF cycles: (1) an optimum in control parameters, (2) the time of completion of synchronized cell division, and (3) the depletion or plateau of the limiting nutrient. Results from this study and literature led to the identification of three potential trends in SCF cycles: (A) co-occurrence of the three key events, (B) cell replication ending prior to the co-occurrence of the other two events, and (C) depletion or plateau of the limiting nutrient occurring later than the co-occurrence of the other two events. Based on these observations, microbial physiological differences were analyzed and a novel definition for SCF is proposed.
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Affiliation(s)
- Yusheng Tan
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada
| | - Lisa Y Stein
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Dominic Sauvageau
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada.
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Tan Y, Agustin RVC, Stein LY, Sauvageau D. Transcriptomic analysis of synchrony and productivity in self-cycling fermentation of engineered yeast producing shikimic acid. BIOTECHNOLOGY REPORTS (AMSTERDAM, NETHERLANDS) 2021; 32:e00691. [PMID: 34934640 PMCID: PMC8660916 DOI: 10.1016/j.btre.2021.e00691] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 11/09/2021] [Accepted: 11/23/2021] [Indexed: 05/25/2023]
Abstract
Industrial fermentation provides a wide variety of bioproducts, such as food, biofuels and pharmaceuticals. Self-cycling fermentation (SCF), an advanced automated semi-continuous fermentation approach, has shown significant advantages over batch reactors (BR); including cell synchrony and improved production. Here, Saccharomyces cerevisiae engineered to overproduce shikimic acid was grown under SCF operation. This led to four-fold increases in product yield and volumetric productivity compared to BR. Transcriptomic analyses were performed to understand the cellular mechanisms leading to these increases. Results indicate an up-regulation of a large number of genes related to the cell cycle and DNA replication in the early stages of SCF cycles, inferring substantial synchronization. Moreover, numerous genes related to gluconeogenesis, the citrate cycle and oxidative phosphorylation were significantly up-regulated in the late stages of SCF cycles, consistent with significant increases in shikimic acid yield and productivity.
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Key Words
- BR, Batch reactor
- CER, Carbon dioxide evolution rate
- DDT, Dithiothreitol
- DNA, Deoxyribonucleic acid
- EDTA, Ethylenediaminetetraacetic acid
- FC, Fold change
- OD600, Optical density at 600 nm
- RNA, Ribonucleic acid
- SCF, Self-cycling fermentation
- STP, Standard temperature and pressure
- Saccharomyces cerevisiae
- Self-cycling fermentation (SCF)
- Shikimic acid
- Synchrony
- Transcriptomics
- cDNA, Complementary deoxyribonucleic acid
- mRNA, Messenger ribonucleic acid
- qPCR, Quantitative polymerase chain reaction
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Affiliation(s)
- Yusheng Tan
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Roman Vincent C. Agustin
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Lisa Y. Stein
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Dominic Sauvageau
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada
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den Haan R, Rose SH, Cripwell RA, Trollope KM, Myburgh MW, Viljoen-Bloom M, van Zyl WH. Heterologous production of cellulose- and starch-degrading hydrolases to expand Saccharomyces cerevisiae substrate utilization: Lessons learnt. Biotechnol Adv 2021; 53:107859. [PMID: 34678441 DOI: 10.1016/j.biotechadv.2021.107859] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 12/28/2022]
Abstract
Selected strains of Saccharomyces cerevisiae are used for commercial bioethanol production from cellulose and starch, but the high cost of exogenous enzymes for substrate hydrolysis remains a challenge. This can be addressed through consolidated bioprocessing (CBP) where S. cerevisiae strains are engineered to express recombinant glycoside hydrolases during fermentation. Looking back at numerous strategies undertaken over the past four decades to improve recombinant protein production in S. cerevisiae, it is evident that various steps in the protein production "pipeline" can be manipulated depending on the protein of interest and its anticipated application. In this review, we briefly introduce some of the strategies and highlight lessons learned with regards to improved transcription, translation, post-translational modification and protein secretion of heterologous hydrolases. We examine how host strain selection and modification, as well as enzyme compatibility, are crucial determinants for overall success. Finally, we discuss how lessons from heterologous hydrolase expression can inform modern synthetic biology and genome editing tools to provide process-ready yeast strains in future. However, it is clear that the successful expression of any particular enzyme is still unpredictable and requires a trial-and-error approach.
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Affiliation(s)
- Riaan den Haan
- Department of Biotechnology, University of the Western Cape, Bellville, South Africa
| | - Shaunita H Rose
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Rosemary A Cripwell
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Kim M Trollope
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Marthinus W Myburgh
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | | | - Willem H van Zyl
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa.
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Bhardwaj N, Kumar B, Agrawal K, Verma P. Current perspective on production and applications of microbial cellulases: a review. BIORESOUR BIOPROCESS 2021; 8:95. [PMID: 38650192 PMCID: PMC10992179 DOI: 10.1186/s40643-021-00447-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 09/21/2021] [Indexed: 12/27/2022] Open
Abstract
The potential of cellulolytic enzymes has been widely studied and explored for bioconversion processes and plays a key role in various industrial applications. Cellulase, a key enzyme for cellulose-rich waste feedstock-based biorefinery, has increasing demand in various industries, e.g., paper and pulp, juice clarification, etc. Also, there has been constant progress in developing new strategies to enhance its production, such as the application of waste feedstock as the substrate for the production of individual or enzyme cocktails, process parameters control, and genetic manipulations for enzyme production with enhanced yield, efficiency, and specificity. Further, an insight into immobilization techniques has also been presented for improved reusability of cellulase, a critical factor that controls the cost of the enzyme at an industrial scale. In addition, the review also gives an insight into the status of the significant application of cellulase in the industrial sector, with its techno-economic analysis for future applications. The present review gives a complete overview of current perspectives on the production of microbial cellulases as a promising tool to develop a sustainable and greener concept for industrial applications.
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Affiliation(s)
- Nisha Bhardwaj
- Bioprocess and Bioenergy Laboratory, Department of Microbiology, Central University of Rajasthan, NH-8, Bandarsindri, Kishangarh, Ajmer, Rajasthan, 305817, India
- Department of Chemical Engineering, Institute of Chemical Technology, Nathalal Parekh Marg, Matunga, Mumbai, Maharashtra, 400019, India
| | - Bikash Kumar
- Bioprocess and Bioenergy Laboratory, Department of Microbiology, Central University of Rajasthan, NH-8, Bandarsindri, Kishangarh, Ajmer, Rajasthan, 305817, India
| | - Komal Agrawal
- Bioprocess and Bioenergy Laboratory, Department of Microbiology, Central University of Rajasthan, NH-8, Bandarsindri, Kishangarh, Ajmer, Rajasthan, 305817, India
| | - Pradeep Verma
- Bioprocess and Bioenergy Laboratory, Department of Microbiology, Central University of Rajasthan, NH-8, Bandarsindri, Kishangarh, Ajmer, Rajasthan, 305817, India.
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Stress modulation as a means to improve yeasts for lignocellulose bioconversion. Appl Microbiol Biotechnol 2021; 105:4899-4918. [PMID: 34097119 DOI: 10.1007/s00253-021-11383-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 05/20/2021] [Accepted: 05/28/2021] [Indexed: 12/15/2022]
Abstract
The second-generation (2G) fermentation environment for lignocellulose conversion presents unique challenges to the fermentative organism that do not necessarily exist in other industrial fermentations. While extreme osmotic, heat, and nutrient starvation stresses are observed in sugar- and starch-based fermentation environments, additional pre-treatment-derived inhibitor stress, potentially exacerbated by stresses such as pH and product tolerance, exist in the 2G environment. Furthermore, in a consolidated bioprocessing (CBP) context, the organism is also challenged to secrete enzymes that may themselves lead to unfolded protein response and other stresses. This review will discuss responses of the yeast Saccharomyces cerevisiae to 2G-specific stresses and stress modulation strategies that can be followed to improve yeasts for this application. We also explore published -omics data and discuss relevant rational engineering, reverse engineering, and adaptation strategies, with the view of identifying genes or alleles that will make positive contributions to the overall robustness of 2G industrial strains. KEYPOINTS: • Stress tolerance is a key driver to successful application of yeast strains in biorefineries. • A wealth of data regarding stress responses has been gained through omics studies. • Integration of this knowledge could inform engineering of fit for purpose strains.
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Lopes AMM, Martins M, Goldbeck R. Heterologous Expression of Lignocellulose-Modifying Enzymes in Microorganisms: Current Status. Mol Biotechnol 2021; 63:184-199. [PMID: 33484441 DOI: 10.1007/s12033-020-00288-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/19/2020] [Indexed: 02/06/2023]
Abstract
Heterologous expression of the carbohydrate-active enzymes in microorganisms is a promising approach to produce bio-based compounds, such as fuels, nutraceuticals and other value-added products from sustainable lignocellulosic sources. Several microorganisms, including Saccharomyces cerevisiae, Escherichia coli, and the filamentous fungi Aspergillus nidulans, have unique characteristics desirable for a biorefinery production approach like well-known genetic tools, thermotolerance, high fermentative capacity and product tolerance, and high amount of recombinant enzyme secretion. These microbial factories are already stablished in the heterologous production of the carbohydrate-active enzymes to produce, among others, ethanol, xylooligosaccharides and the valuable coniferol. A complete biocatalyst able to heterologous express the CAZymes of glycoside hydrolases, carbohydrate esterases and auxiliary activities families could release these compounds faster, with higher yield and specificity. Recent advances in the synthetic biology tools could expand the number and diversity of enzymes integrated in these microorganisms, and also modify those already integrated. This review outlines the heterologous expression of carbohydrate-active enzymes in microorganisms, as well as recent updates in synthetic biology.
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Affiliation(s)
- Alberto Moura Mendes Lopes
- Bioprocess and Metabolic Engineering Laboratory, School of Food Engineering, University of Campinas (UNICAMP), Rua Monteiro Lobato no 80, Cidade Universitária, Campinas, São Paulo, 13083-862, Brazil
| | - Manoela Martins
- Bioprocess and Metabolic Engineering Laboratory, School of Food Engineering, University of Campinas (UNICAMP), Rua Monteiro Lobato no 80, Cidade Universitária, Campinas, São Paulo, 13083-862, Brazil
| | - Rosana Goldbeck
- Bioprocess and Metabolic Engineering Laboratory, School of Food Engineering, University of Campinas (UNICAMP), Rua Monteiro Lobato no 80, Cidade Universitária, Campinas, São Paulo, 13083-862, Brazil.
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Lu J, Li J, Gao H, Zhou D, Xu H, Cong Y, Zhang W, Xin F, Jiang M. Recent progress on bio-succinic acid production from lignocellulosic biomass. World J Microbiol Biotechnol 2021; 37:16. [PMID: 33394223 DOI: 10.1007/s11274-020-02979-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/05/2020] [Indexed: 11/28/2022]
Abstract
Succinic acid is a valuable bulk chemical, which has been extensively applied in food, medicine, surfactants and biodegradable plastics industries. As a substitute for chemical raw material, bio-based succinic acid production has received increasing attention due to the depletion of fossil fuels and environmental issues. Meanwhile, the effective bioconversion of lignocellulosic biomass has always been a hot spot of interest owning to the advantages of low expense, abundance and renewability. Consolidated bioprocessing (CBP) is considered to be an alternative approach with outstanding potential, as CBP can not only improve the product yield and productivity, but also reduce the equipment and operating costs. In addition, the current emerging microbial co-cultivation systems provide strong competitiveness for lignocellulose utilization through CBP. This article comprehensively discusses different strategies for the bioconversion of lignocellulose to succinic acid. Based on the principles and technical concepts of CBP, this review focuses on the progress of succinic acid production under different CBP strategies (metabolic engineering based and microbial co-cultivation based). Moreover, the main challenges faced by CBP-based succinic acid fermentation are analyzed, and the future direction of CBP production is prospected.
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Affiliation(s)
- Jiasheng Lu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China
| | - Jiawen Li
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China
| | - Hao Gao
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China
| | - Dawei Zhou
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China
| | - Huixin Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China
| | - Yuexin Cong
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China
| | - Wenming Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China. .,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816, People's Republic of China.
| | - Fengxue Xin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China. .,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816, People's Republic of China.
| | - Min Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816, People's Republic of China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816, People's Republic of China
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11
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Microbial lignin peroxidases: Applications, production challenges and future perspectives. Enzyme Microb Technol 2020; 141:109669. [DOI: 10.1016/j.enzmictec.2020.109669] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/09/2020] [Accepted: 09/10/2020] [Indexed: 12/19/2022]
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12
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Cunha JT, Romaní A, Inokuma K, Johansson B, Hasunuma T, Kondo A, Domingues L. Consolidated bioprocessing of corn cob-derived hemicellulose: engineered industrial Saccharomyces cerevisiae as efficient whole cell biocatalysts. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:138. [PMID: 32782474 PMCID: PMC7414751 DOI: 10.1186/s13068-020-01780-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 07/29/2020] [Indexed: 05/24/2023]
Abstract
BACKGROUND Consolidated bioprocessing, which combines saccharolytic and fermentative abilities in a single microorganism, is receiving increased attention to decrease environmental and economic costs in lignocellulosic biorefineries. Nevertheless, the economic viability of lignocellulosic ethanol is also dependent of an efficient utilization of the hemicellulosic fraction, which contains xylose as a major component in concentrations that can reach up to 40% of the total biomass in hardwoods and agricultural residues. This major bottleneck is mainly due to the necessity of chemical/enzymatic treatments to hydrolyze hemicellulose into fermentable sugars and to the fact that xylose is not readily consumed by Saccharomyces cerevisiae-the most used organism for large-scale ethanol production. In this work, industrial S. cerevisiae strains, presenting robust traits such as thermotolerance and improved resistance to inhibitors, were evaluated as hosts for the cell-surface display of hemicellulolytic enzymes and optimized xylose assimilation, aiming at the development of whole-cell biocatalysts for consolidated bioprocessing of corn cob-derived hemicellulose. RESULTS These modifications allowed the direct production of ethanol from non-detoxified hemicellulosic liquor obtained by hydrothermal pretreatment of corn cob, reaching an ethanol titer of 11.1 g/L corresponding to a yield of 0.328 g/g of potential xylose and glucose, without the need for external hydrolytic catalysts. Also, consolidated bioprocessing of pretreated corn cob was found to be more efficient for hemicellulosic ethanol production than simultaneous saccharification and fermentation with addition of commercial hemicellulases. CONCLUSIONS These results show the potential of industrial S. cerevisiae strains for the design of whole-cell biocatalysts and paves the way for the development of more efficient consolidated bioprocesses for lignocellulosic biomass valorization, further decreasing environmental and economic costs.
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Affiliation(s)
- Joana T. Cunha
- CEB–Centre of Biological Engineering, University of Minho, Campus Gualtar, Braga, Portugal
| | - Aloia Romaní
- CEB–Centre of Biological Engineering, University of Minho, Campus Gualtar, Braga, Portugal
| | - Kentaro Inokuma
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501 Japan
| | - Björn Johansson
- Center of Molecular and Environmental Biology (CBMA), University of Minho, Braga, Portugal
| | - Tomohisa Hasunuma
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501 Japan
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501 Japan
| | - Akihiko Kondo
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501 Japan
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501 Japan
| | - Lucília Domingues
- CEB–Centre of Biological Engineering, University of Minho, Campus Gualtar, Braga, Portugal
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13
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Enzymatic Hydrolysis of Softwood Derived Paper Sludge by an In Vitro Recombinant Cellulase Cocktail for the Production of Fermentable Sugars. Catalysts 2020. [DOI: 10.3390/catal10070775] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Paper sludge is an attractive biomass feedstock for bioconversion to ethanol due to its low cost and the lack of pretreatment required for its bioprocessing. This study assessed the use of a recombinant cellulase cocktail (mono-components: S. cerevisiae-derived PcBGL1B (BGL), TeCel7A (CBHI), ClCel6A (CBHII) and TrCel5A (EGII) mono-component cellulase enzymes) for the efficient saccharification of softwood-derived paper sludge to produce fermentable sugars. The paper sludge mainly contained 74.3% moisture and 89.7% (per dry mass (DM)) glucan with a crystallinity index of 91.5%. The optimal protein ratio for paper sludge hydrolysis was observed at 9.4: 30.2: 30.2: 30.2% for BGL: CBHI: CBHII: EGII. At a protein loading of 7.5 mg/g DW paper sludge, the yield from hydrolysis was approximately 80%, based on glucan, with scanning electron microscopy micrographs indicating a significant alteration in the microfibril size (length reduced from ≥ 2 mm to 93 µm) of the paper sludge. The paper sludge hydrolysis potential of the Opt CelMix (formulated cellulase cocktail) was similar to the commercial Cellic CTec2® and Celluclast® 1.5 L cellulase preparations and better than Viscozyme® L. Low enzyme loadings (15 mg/g paper sludge) of the Opt CelMix and solid loadings ranging between 1 to 10% (w/v) rendered over 80% glucan conversion. The high glucose yields attained on the paper sludge by the low enzyme loading of the Opt CelMix demonstrated the value of enzyme cocktail optimisation on specific substrates for efficient cellulose conversion to fermentable sugars.
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14
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Lamour J, Wan C, Zhang M, Zhao X, Den Haan R. Overexpression of endogenous stress-tolerance related genes in Saccharomyces cerevisiae improved strain robustness and production of heterologous cellobiohydrolase. FEMS Yeast Res 2020; 19:5479884. [PMID: 31073597 DOI: 10.1093/femsyr/foz035] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 04/25/2019] [Indexed: 12/11/2022] Open
Abstract
To enable Saccharomyces cerevisiae to produce renewable fuels from lignocellulose in a consolidated bioprocess, a heterologous cellulase system must be engineered into this yeast. In addition, inherently low secretion titers and sensitivity to adverse environmental conditions must be overcome. Here, two native S. cerevisiae genes related to yeast stress tolerance, YHB1 and SET5, were overexpressed under transcriptional control of the constitutive PGK1 promoter and their effects on heterologous secretion of Talaromyces emersonii cel7A cellobiohydrolase was investigated. Transformants showed increased secreted enzyme activity that ranged from 22% to 55% higher compared to the parental strains and this did not lead to deleterious growth effects. The recombinant strains overexpressing either YHB1 or SET5 also demonstrated multi-tolerant characteristics desirable in bioethanol production, i.e. improved tolerance to osmotic and heat stress. Quantitative reverse transcriptase PCR analysis in these strains showed decreased transcription of secretion pathway genes. However, decreased unfolded protein response was also observed, suggesting novel mechanisms for enhancing enzyme production through stress modulation. Overexpression of YHB1 in an unrelated diploid strain also enhanced stress tolerance and improved ethanol productivity in medium containing acetic acid. To our knowledge, this is the first demonstration that improved heterologous secretion and environmental stress tolerance could be engineered into yeast simultaneously.
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Affiliation(s)
- Jarryd Lamour
- Department of Biotechnology, University of the Western Cape, Bellville 7530, South Africa
| | - Chun Wan
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Mingming Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xinqing Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Riaan Den Haan
- Department of Biotechnology, University of the Western Cape, Bellville 7530, South Africa
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15
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Exploiting strain diversity and rational engineering strategies to enhance recombinant cellulase secretion by Saccharomyces cerevisiae. Appl Microbiol Biotechnol 2020; 104:5163-5184. [PMID: 32337628 DOI: 10.1007/s00253-020-10602-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 03/26/2020] [Accepted: 03/31/2020] [Indexed: 12/14/2022]
Abstract
Consolidated bioprocessing (CBP) of lignocellulosic material into bioethanol has progressed in the past decades; however, several challenges still exist which impede the industrial application of this technology. Identifying the challenges that exist in all unit operations is crucial and needs to be optimised, but only the barriers related to the secretion of recombinant cellulolytic enzymes in Saccharomyces cerevisiae will be addressed in this review. Fundamental principles surrounding CBP as a biomass conversion platform have been established through the successful expression of core cellulolytic enzymes, namely β-glucosidases, endoglucanases, and exoglucanases (cellobiohydrolases) in S. cerevisiae. This review will briefly address the challenges involved in the construction of an efficient cellulolytic yeast, with particular focus on the secretion efficiency of cellulases from this host. Additionally, strategies for studying enhanced cellulolytic enzyme secretion, which include both rational and reverse engineering approaches, will be discussed. One such technique includes bio-engineering within genetically diverse strains, combining the strengths of both natural strain diversity and rational strain development. Furthermore, with the advancement in next-generation sequencing, studies that utilise this method of exploiting intra-strain diversity for industrially relevant traits will be reviewed. Finally, future prospects are discussed for the creation of ideal CBP strains with high enzyme production levels.Key Points• Several challenges are involved in the construction of efficient cellulolytic yeast, in particular, the secretion efficiency of cellulases from the hosts.• Strategies for enhancing cellulolytic enzyme secretion, a core requirement for CBP host microorganism development, include both rational and reverse engineering approaches.• One such technique includes bio-engineering within genetically diverse strains, combining the strengths of both natural strain diversity and rational strain development.
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16
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Engineering of industrially important microorganisms for assimilation of cellulosic biomass: towards consolidated bioprocessing. Biochem Soc Trans 2020; 47:1781-1794. [PMID: 31845725 DOI: 10.1042/bst20190293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 11/28/2019] [Accepted: 11/28/2019] [Indexed: 01/01/2023]
Abstract
Conversion of cellulosic biomass (non-edible plant material) to products such as chemical feedstocks and liquid fuels is a major goal of industrial biotechnology and an essential component of plans to move from an economy based on fossil carbon to one based on renewable materials. Many microorganisms can effectively degrade cellulosic biomass, but attempts to engineer this ability into industrially useful strains have met with limited success, suggesting an incomplete understanding of the process. The recent discovery and continuing study of enzymes involved in oxidative depolymerisation, as well as more detailed study of natural cellulose degradation processes, may offer a way forward.
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17
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Cedras G, Kroukamp H, Van Zyl WH, Den Haan R. The
in vivo
detection and measurement of the unfolded protein response in recombinant cellulase producing
Saccharomyces cerevisiae
strains. Biotechnol Appl Biochem 2020; 67:82-94. [DOI: 10.1002/bab.1819] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 08/16/2019] [Indexed: 11/10/2022]
Affiliation(s)
- Gillian Cedras
- Department of BiotechnologyUniversity of the Western Cape Bellville South Africa
| | - Heinrich Kroukamp
- Department of Molecular SciencesMacquarie University North Ryde NSW Australia
| | | | - Riaan Den Haan
- Department of BiotechnologyUniversity of the Western Cape Bellville South Africa
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18
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Improved cellulase expression in diploid yeast strains enhanced consolidated bioprocessing of pretreated corn residues. Enzyme Microb Technol 2019; 131:109382. [DOI: 10.1016/j.enzmictec.2019.109382] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 06/27/2019] [Accepted: 07/12/2019] [Indexed: 01/12/2023]
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19
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Huertas MJ, Michán C. Paving the way for the production of secretory proteins by yeast cell factories. Microb Biotechnol 2019; 12:1095-1096. [PMID: 30735012 PMCID: PMC6801135 DOI: 10.1111/1751-7915.13342] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 11/06/2018] [Indexed: 01/23/2023] Open
Affiliation(s)
- Maria José Huertas
- Instituto de Bioquímica Vegetal y FotosíntesisUniversidad de Sevilla‐CSICAmérico Vespucio 4941092SevillaSpain
| | - Carmen Michán
- Departamento de Bioquímica y Biología MolecularCampus de Excelencia Internacional Agroalimentario CeiA3Universidad de CórdobaEdificio Severo Ochoa C‐6, 2Planta14071CórdobaSpain
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20
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Davison SA, den Haan R, van Zyl WH. Identification of superior cellulase secretion phenotypes in haploids derived from natural Saccharomyces cerevisiae isolates. FEMS Yeast Res 2019; 19:5154912. [PMID: 30388213 DOI: 10.1093/femsyr/foy117] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 10/31/2018] [Indexed: 01/11/2023] Open
Abstract
The yeast Saccharomyces cerevisiae is considered an important host for consolidated bioprocessing and the production of high titres of recombinant cellulases is required for efficient hydrolysis of lignocellulosic substrates to fermentable sugars. Since recombinant protein secretion profiles vary highly among different strain backgrounds, careful selection of robust strains with optimal secretion profiles is of crucial importance. Here, we construct and screen sets of haploid derivatives, derived from natural strain isolates YI13, FINI and YI59, for improved general cellulase secretion. This report details a novel approach that combines secretion profiles of strains and phenotypic responses to stresses known to influence the secretion pathway for the development of a phenotypic screen to isolate strains with improved secretory capacities. A clear distinction was observed between the YI13 haploid derivatives and industrial and laboratory counterparts, Ethanol Red and S288c, respectively. By using sub-lethal concentrations of the secretion stressor tunicamycin and cell wall stressor Congo Red, YI13 haploid derivative strains demonstrated tolerance profiles related to their heterologous secretion profiles. Our results demonstrated that a new screening technique combined with a targeted mating approach could produce a pool of novel strains capable of high cellulase secretion.
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Affiliation(s)
- Steffi A Davison
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Riaan den Haan
- Department of Biotechnology, University of the Western Cape, Bellville 7535, South Africa
| | - Willem Heber van Zyl
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
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21
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Favaro L, Jansen T, van Zyl WH. Exploring industrial and naturalSaccharomyces cerevisiaestrains for the bio-based economy from biomass: the case of bioethanol. Crit Rev Biotechnol 2019; 39:800-816. [DOI: 10.1080/07388551.2019.1619157] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Lorenzo Favaro
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), University of Padova, Legnaro, Italy
| | - Trudy Jansen
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
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22
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The biotechnological potential of the yeast Dekkera bruxellensis. World J Microbiol Biotechnol 2019; 35:103. [PMID: 31236799 DOI: 10.1007/s11274-019-2678-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Accepted: 06/15/2019] [Indexed: 10/26/2022]
Abstract
Dekkera bruxellensis is an industrial yeast mainly regarded as a contaminant species in fermentation processes. In winemaking, it is associated with off-flavours that cause wine spoilage, while in bioethanol production this yeast is linked to a reduction of industrial productivity by competing with Saccharomyces cerevisiae for the substrate. In spite of that, this point of view is gradually changing, mostly because D. bruxellensis is also able to produce important metabolites, such as ethanol, acetate, fusel alcohols, esters and others. This dual role is likely due to the fact that this yeast presents a set of metabolic traits that might be either industrially attractive or detrimental, depending on how they are faced and explored. Therefore, a proper industrial application for D. bruxellensis depends on the correct assembly of its central metabolic puzzle. In this sense, researchers have addressed issues regarding the physiological and genetic aspects of D. bruxellensis, which have brought to light much of our current knowledge on this yeast. In this review, we shall outline what is presently understood about the main metabolic features of D. bruxellensis and how they might be managed to improve its current or future industrial applications (except for winemaking, in which it is solely regarded as a contaminant). Moreover, we will discuss the advantages and challenges that must be overcome in order to take advantage of the full biotechnological potential of this yeast.
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23
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Engineering the early secretory pathway for increased protein secretion in Saccharomyces cerevisiae. Metab Eng 2019; 55:142-151. [PMID: 31220665 DOI: 10.1016/j.ymben.2019.06.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 05/31/2019] [Accepted: 06/17/2019] [Indexed: 11/21/2022]
Abstract
The yeast Saccharomyces cerevisiae is a valuable host for the production of heterologous proteins with a wide array of applications, ranging from cellulose saccharification enzymes to biopharmaceuticals. Efficient protein secretion may be critical for economic viability; however previous efforts have shown limited improvements that are often protein-specific. By enhancing transit through the early secretory pathway, we have successfully improved extracellular levels of three different proteins from variety of origins: a bacterial endoglucanase (CelA), a fungal β-glucosidase (BglI) and a single-chain antibody fragment (4-4-20 scFv). Efficient co-translational translocation into the endoplasmic reticulum (ER) was achieved via secretion peptide engineering and the novel use of a 3'-untranslated region, improving extracellular activity or fluorescence 2.2-5.4-fold. We further optimized the pathway using a variety of new strategies including: i) increasing secretory pathway capacity by expanding the ER, ii) limiting ER-associated degradation, and iii) enhancing exit from the ER. By addressing these additional ER processing steps, extracellular activity/fluorescence increased by 3.5-7.1-fold for the three diverse proteins. The optimal combination of pathway interventions varied, and the highest overall increases ranged from 5.8 to 11-fold. These successful strategies should prove effective for improving the secretion of a wide range of heterologous proteins.
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24
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Cagnin L, Favaro L, Gronchi N, Rose SH, Basaglia M, van Zyl WH, Casella S. Comparing laboratory and industrial yeast platforms for the direct conversion of cellobiose into ethanol under simulated industrial conditions. FEMS Yeast Res 2019; 19:5333308. [DOI: 10.1093/femsyr/foz018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Accepted: 02/15/2019] [Indexed: 11/13/2022] Open
Affiliation(s)
- Lorenzo Cagnin
- Department of Agronomy Food Natural resources Animals and Enviroment (DAFNAE), University of Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro (PD), Italy
| | - Lorenzo Favaro
- Department of Agronomy Food Natural resources Animals and Enviroment (DAFNAE), University of Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro (PD), Italy
| | - Nicoletta Gronchi
- Department of Agronomy Food Natural resources Animals and Enviroment (DAFNAE), University of Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro (PD), Italy
| | - Shaunita Hellouise Rose
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland, 7602, Stellenbosch, South Africa
| | - Marina Basaglia
- Department of Agronomy Food Natural resources Animals and Enviroment (DAFNAE), University of Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro (PD), Italy
| | - Willem Heber van Zyl
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland, 7602, Stellenbosch, South Africa
| | - Sergio Casella
- Department of Agronomy Food Natural resources Animals and Enviroment (DAFNAE), University of Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro (PD), Italy
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25
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Yang P, Wu Y, Zheng Z, Cao L, Zhu X, Mu D, Jiang S. CRISPR-Cas9 Approach Constructing Cellulase sestc-Engineered Saccharomyces cerevisiae for the Production of Orange Peel Ethanol. Front Microbiol 2018; 9:2436. [PMID: 30364071 PMCID: PMC6191481 DOI: 10.3389/fmicb.2018.02436] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 09/24/2018] [Indexed: 11/25/2022] Open
Abstract
The development of lignocellulosic bioethanol plays an important role in the substitution of petrochemical energy and high-value utilization of agricultural wastes. The safe and stable expression of cellulase gene sestc was achieved by applying the clustered regularly interspaced short palindromic repeats-Cas9 approach to the integration of sestc expression cassette containing Agaricus biporus glyceraldehyde-3-phosphate-dehydrogenase gene (gpd) promoter in the Saccharomyces cerevisiae chromosome. The target insertion site was found to be located in the S. cerevisiae hexokinase 2 by designing a gRNA expression vector. The recombinant SESTC protein exhibited a size of approximately 44 kDa in the engineered S. cerevisiae. By using orange peel as the fermentation substrate, the filter paper, endo-1,4-β-glucanase, exo-1,4-β-glucanase activities of the transformants were 1.06, 337.42, and 1.36 U/mL, which were 35.3-fold, 23.03-fold, and 17-fold higher than those from wild-type S. cerevisiae, respectively. After 6 h treatment, approximately 20 g/L glucose was obtained. Under anaerobic conditions the highest ethanol concentration reached 7.53 g/L after 48 h fermentation and was 37.7-fold higher than that of wild-type S. cerevisiae (0.2 g/L). The engineered strains may provide a valuable material for the development of lignocellulosic ethanol.
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Affiliation(s)
- Peizhou Yang
- College of Food and Biological Engineering, Anhui Key Laboratory of Intensive Processing of Agricultural Products, Hefei University of Technology, Hefei, China
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26
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Karakus BZ, Korkmaz İ, Demirci K, Sinan Arslan K, Unlu O, Catal T. A combined treatment using ethylmethane sulfonate and ultraviolet light to compare amylase production by three Bacillus sp. isolates. Prep Biochem Biotechnol 2018; 48:815-822. [PMID: 30265205 DOI: 10.1080/10826068.2018.1509088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
In this study, three Bacillus sp.-producing amylase enzymes were isolated from soil samples and identified using 16S rDNA sequence analysis. Amylase production and total protein productions were spectrophotometrically measured. The following media were tested to increase enzyme production: LB medium and molasses. Three Bacillus sp. were identified as follows: Bacillus subtilis subtilis, Bacillus thuringiensis, and Bacillus cereus. Amylase production levels were in the range of 10 U/mL, whereas total protein production levels were at 15 mg/mL. Higher amylase activity was found in the Bacillus subtilis isolate. Ethylmethane sulfonate (EMS) and ultraviolet (UV) mutagenesis in combination were applied to compare amylase production. Amylase activity was increased to around 58% in the treatment with 0.03 mL of EMS and UV when compared to the control group. A pilot scale bioreactor with a total working volume of 10 liters was used to produce amylase by B. subtilis subtilis. In conclusion, B. subtilis subtilis can be used to produce amylase enzyme for various industrial purposes, and, for the first time, the amylase activities of B. subtilis can be enhanced with EMS and UV treatment.
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Affiliation(s)
- Betul Zehra Karakus
- a Istanbul Protein Reserach and Inovation Center (PROMER) , Istanbul , Turkey
| | - İlknur Korkmaz
- a Istanbul Protein Reserach and Inovation Center (PROMER) , Istanbul , Turkey
| | - Kubra Demirci
- a Istanbul Protein Reserach and Inovation Center (PROMER) , Istanbul , Turkey
| | - Kadir Sinan Arslan
- a Istanbul Protein Reserach and Inovation Center (PROMER) , Istanbul , Turkey
| | - Ozge Unlu
- a Istanbul Protein Reserach and Inovation Center (PROMER) , Istanbul , Turkey
| | - Tunc Catal
- a Istanbul Protein Reserach and Inovation Center (PROMER) , Istanbul , Turkey.,b Department of Molecular Biology and Genetics , Uskudar University , Istanbul , Turkey
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27
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Liu ZL, Li HN, Song HT, Xiao WJ, Xia WC, Liu XP, Jiang ZB. Construction of a trifunctional cellulase and expression in Saccharomyces cerevisiae using a fusion protein. BMC Biotechnol 2018; 18:43. [PMID: 30005661 PMCID: PMC6044064 DOI: 10.1186/s12896-018-0454-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 07/04/2018] [Indexed: 01/11/2023] Open
Abstract
Background Cellulose is the most important component of lignocellulose, and its degradation requires three different types of enzymes to act synergistically. There have been reports of single gene duality, but no gene has been described to have more than two functions. Cloning and expression of fusion cellulases containing more than two kinds of catalytic domains has not been reported thus far. Results We synthesized three different cellulase genes and linked the three catalytic domains with a (G4S)3 flexible linker. The trifunctional cellulase gene (BCE) containing three types of cellulase functions was constructed and expressed in S. cerevisiae successfully. The β-glucosidase, the exoglucanase and the endoglucanase activity of the trifunctional cellulase BCE reached 16.80 IU/mg, 2.26 IU/mg and 20.67 IU/mg, which was 46.27, 6.73 and 46.20% higher than the activities of the β-glucosidase BG, the endoglucanase CBH and the endoglucanase EG. The filter paper enzyme activity of BCE was higher than those of BG, CBH and EG, reached 2.04 IU/mg. Conclusions The trifunctional cellulase BCE was designed based on β-glucosidase BG, endoglucanase EG and exoglucanase CBH, and it possessed β-glucosidase activity, endoglucanase activity and exoglucanase activity simultaneously. The BCE has better filter paper activity, it means the potential practical application. Electronic supplementary material The online version of this article (10.1186/s12896-018-0454-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zi-Lu Liu
- Hubei Key Laboratory of Industrial Biotechnology College of Life Science, Hubei University, Wuhan, 430062, People's Republic of China.,Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei University, Wuhan, 430062, People's Republic of China
| | - Hua-Nan Li
- Hubei Key Laboratory of Industrial Biotechnology College of Life Science, Hubei University, Wuhan, 430062, People's Republic of China
| | - Hui-Ting Song
- Hubei Key Laboratory of Industrial Biotechnology College of Life Science, Hubei University, Wuhan, 430062, People's Republic of China.,College of Resources and Environmental Science, Hubei University, Wuhan, 430062, People's Republic of China
| | - Wen-Jing Xiao
- Hubei Key Laboratory of Industrial Biotechnology College of Life Science, Hubei University, Wuhan, 430062, People's Republic of China
| | - Wu-Cheng Xia
- Hubei Key Laboratory of Industrial Biotechnology College of Life Science, Hubei University, Wuhan, 430062, People's Republic of China
| | - Xiao-Peng Liu
- Department of Biological Science and Technology, Hubei University for Nationalities, Ensi, 445000, People's Republic of China
| | - Zheng-Bing Jiang
- Hubei Key Laboratory of Industrial Biotechnology College of Life Science, Hubei University, Wuhan, 430062, People's Republic of China. .,Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei University, Wuhan, 430062, People's Republic of China.
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28
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Ding J, Liang G, Zhang K, Hong J, Zou S, Lu H, Ma Y, Zhang M. Extra metabolic burden by displaying over secreting: Growth, fermentation and enzymatic activity in cellobiose of recombinant yeast expressing β-glucosidase. BIORESOURCE TECHNOLOGY 2018; 254:107-114. [PMID: 29413910 DOI: 10.1016/j.biortech.2017.12.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 12/09/2017] [Accepted: 12/11/2017] [Indexed: 06/08/2023]
Abstract
β-Glucosidase was selected to be a reporter to study metabolic burden imposed by its expression in yeast. Cell growth, fermentation yield and enzymatic activity were used as indicators of the metabolic burden borne by 14 recombinant yeast strains. Various factors were found to affect metabolic burden, including BGLI gene source, gene dose, trafficking of the enzyme (either cell-surface display or secretion), and oxygen supply. While BGLI gene from Aspergillus aculeatus provided better performance for the host cells than that from Saccharomycopsis fibuligera, displaying β-glucosidase on the cell surface generally led to lower μm, total activity and ethanol titer, and longer lag period, lower (aerobic condition) or higher (anaerobic condition) biomass yield than that of secreting β-glucosidase. The negative effect on growth increased with gene dose level until a final failure to grow. This growth difference implies that displaying β-glucosidase on the cell surface imposes an extra metabolic burden. The molecular basis and mechanisms for this phenomenon need to further be investigated in order to develop better strategies for utilizing displayed and secreted enzymes in biotechnology and yeast breeding.
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Affiliation(s)
- Juanjuan Ding
- Tianjin R&D Center for Petrochemical Technology, Tianjin University, Tianjin 300072, China; Key Laboratory of Systems Bioengineering, Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Guohong Liang
- Key Laboratory of Systems Bioengineering, Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Kun Zhang
- Tianjin R&D Center for Petrochemical Technology, Tianjin University, Tianjin 300072, China; School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China
| | - Jiefang Hong
- Tianjin R&D Center for Petrochemical Technology, Tianjin University, Tianjin 300072, China
| | - Shaolan Zou
- Tianjin R&D Center for Petrochemical Technology, Tianjin University, Tianjin 300072, China; Key Laboratory of Systems Bioengineering, Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
| | - Haiyan Lu
- Key Laboratory of Systems Bioengineering, Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Yuanyuan Ma
- Tianjin R&D Center for Petrochemical Technology, Tianjin University, Tianjin 300072, China
| | - Minhua Zhang
- Tianjin R&D Center for Petrochemical Technology, Tianjin University, Tianjin 300072, China; Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University, Tianjin 300072, China; State Key Laboratory of Engine, Tianjin University, Tianjin 300072, China
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29
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Manfrão-Netto JHC, Mello-de-Sousa TM, Mach-Aigner AR, Mach RL, Poças-Fonseca MJ. The DNA-methyltransferase inhibitor 5-aza-2-deoxycytidine affects Humicola grisea enzyme activities and the glucose-mediated gene repression. J Basic Microbiol 2017; 58:144-153. [PMID: 29193198 DOI: 10.1002/jobm.201700415] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 10/27/2017] [Accepted: 11/09/2017] [Indexed: 11/07/2022]
Abstract
Humicola grisea var. thermoidea (Hgvt) is a thermophilic ascomycete that produces lignocellulolytic enzymes and it is proposed for the conversion of agricultural residues into useful byproducts. Drugs that inhibit the DNA methyltransferases (DNMTs) activity are employed in epigenetic studies but nothing is known about a possible effect on the production of fungal enzymes. We evaluated the effect of 5-aza-2'-deoxycytidine (5-Aza; a chemical inhibitor of DNMTs activity) on the secreted enzyme activity and on the transcription of cellulase and xylanase genes from Hgvt grown in agricultural residues and in glucose. Upon cultivation on wheat bran (WB), the drug provoked an increase in the xylanase activity at 96 h. When Hgvt was grown in glucose (GLU), a repressor of Hgvt glycosyl hydrolase genes, 5-Aza led to increased transcript accumulation for the cellobiohydrolases and for the xyn2 xylanase genes. In WB, 5-Aza enhanced the expression of the transcription factor CreA gene. Growth on WB or GLU, in presence of 5-Aza, led to a significant increase in transcripts of the pH-response regulator PacC gene. To our knowledge, this is the first report on the effect of a DNMT inhibitor in the production of fungal plant cell wall degradation enzymes.
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Affiliation(s)
| | - Thiago M Mello-de-Sousa
- Research Area of Biochemical Technology, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria
| | - Astrid R Mach-Aigner
- Research Area of Biochemical Technology, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria
| | - Robert L Mach
- Research Area of Biochemical Technology, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria
| | - Marcio J Poças-Fonseca
- Graduation Program in Molecular Biology, University of Brasilia, Brasilia-DF, Brazil.,Department of Genetics and Morphology, University of Brasilia, Brasilia-DF, Brazil
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30
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Lee CR, Sung BH, Lim KM, Kim MJ, Sohn MJ, Bae JH, Sohn JH. Co-fermentation using Recombinant Saccharomyces cerevisiae Yeast Strains Hyper-secreting Different Cellulases for the Production of Cellulosic Bioethanol. Sci Rep 2017; 7:4428. [PMID: 28667330 PMCID: PMC5493647 DOI: 10.1038/s41598-017-04815-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 05/19/2017] [Indexed: 01/02/2023] Open
Abstract
To realize the economical production of ethanol and other bio-based chemicals from lignocellulosic biomass by consolidated bioprocessing (CBP), various cellulases from different sources were tested to improve the level of cellulase secretion in the yeast Saccharomyces cerevisiae by screening an optimal translational fusion partner (TFP) as both a secretion signal and fusion partner. Among them, four indispensable cellulases for cellulose hydrolysis, including Chaetomium thermophilum cellobiohydrolase (CtCBH1), Chrysosporium lucknowense cellobiohydrolase (ClCBH2), Trichoderma reesei endoglucanase (TrEGL2), and Saccharomycopsis fibuligera β-glucosidase (SfBGL1), were identified to be highly secreted in active form in yeast. Despite variability in the enzyme levels produced, each recombinant yeast could secrete approximately 0.6–2.0 g/L of cellulases into the fermentation broth. The synergistic effect of the mixed culture of the four strains expressing the essential cellulases with the insoluble substrate Avicel and several types of cellulosic biomass was demonstrated to be effective. Co-fermentation of these yeast strains produced approximately 14 g/L ethanol from the pre-treated rice straw containing 35 g/L glucan with 3-fold higher productivity than that of wild type yeast using a reduced amount of commercial cellulases. This process will contribute to the cost-effective production of bioenergy such as bioethanol and biochemicals from cellulosic biomass.
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Affiliation(s)
- Cho-Ryong Lee
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 34141, Republic of Korea.,Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, Korea University of Science and Technology (UST), Daejeon, 34113, Republic of Korea
| | - Bong Hyun Sung
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 34141, Republic of Korea.,Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, Korea University of Science and Technology (UST), Daejeon, 34113, Republic of Korea
| | - Kwang-Mook Lim
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 34141, Republic of Korea
| | - Mi-Jin Kim
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 34141, Republic of Korea
| | - Min Jeong Sohn
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 34141, Republic of Korea
| | - Jung-Hoon Bae
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 34141, Republic of Korea
| | - Jung-Hoon Sohn
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 34141, Republic of Korea. .,Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, Korea University of Science and Technology (UST), Daejeon, 34113, Republic of Korea.
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31
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Synergies in coupled hydrolysis and fermentation of cellulose using a Trichoderma reesei enzyme preparation and a recombinant Saccharomyces cerevisiae strain. World J Microbiol Biotechnol 2017; 33:140. [DOI: 10.1007/s11274-017-2308-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 06/01/2017] [Indexed: 11/27/2022]
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