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Sharma J, Kumar V, Prasad R, Gaur NA. Engineering of Saccharomyces cerevisiae as a consolidated bioprocessing host to produce cellulosic ethanol: Recent advancements and current challenges. Biotechnol Adv 2022; 56:107925. [DOI: 10.1016/j.biotechadv.2022.107925] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/24/2022] [Accepted: 02/06/2022] [Indexed: 01/01/2023]
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Wightman ELI, Kroukamp H, Pretorius IS, Paulsen IT, Nevalainen HKM. Rapid optimisation of cellulolytic enzymes ratios in Saccharomyces cerevisiae using in vitro SCRaMbLE. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:182. [PMID: 33292481 PMCID: PMC7607656 DOI: 10.1186/s13068-020-01823-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 10/23/2020] [Indexed: 05/12/2023]
Abstract
BACKGROUND For the economic production of biofuels and other valuable products from lignocellulosic waste material, a consolidated bioprocessing (CBP) organism is required. With efficient fermentation capability and attractive industrial qualities, Saccharomyces cerevisiae is a preferred candidate and has been engineered to produce enzymes that hydrolyze cellulosic biomass. Efficient cellulose hydrolysis requires the synergistic action of several enzymes, with the optimum combined activity ratio dependent on the composition of the substrate. RESULTS In vitro SCRaMbLE generated a library of plasmids containing different ratios of a β-glucosidase gene (CEL3A) from Saccharomycopsis fibuligera and an endoglucanase gene (CEL5A) from Trichoderma reesei. S. cerevisiae, transformed with the plasmid library, displayed a range of individual enzyme activities and synergistic capabilities. Furthermore, we show for the first time that 4,6-O-(3-ketobutylidene)-4-nitrophenyl-β-D-cellopentaoside (BPNPG5) is a suitable substrate to determine synergistic Cel3A and Cel5A action and an accurate predictive model for this synergistic action was devised. Strains with highest BPNPG5 activity had an average CEL3A and CEL5A gene cassette copy number of 1.3 ± 0.6 and 0.8 ± 0.2, respectively (ratio of 1.6:1). CONCLUSIONS Here, we describe a synthetic biology approach to rapidly optimise gene copy numbers to achieve efficient synergistic substrate hydrolysis. This study demonstrates how in vitro SCRaMbLE can be applied to rapidly combine gene constructs in various ratios to allow screening of synergistic enzyme activities for efficient substrate hydrolysis.
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Affiliation(s)
- Elizabeth L I Wightman
- Centre of Excellence in Synthetic Biology, Department of Molecular Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Heinrich Kroukamp
- Centre of Excellence in Synthetic Biology, Department of Molecular Sciences, Macquarie University, Sydney, NSW, 2109, Australia.
- Biomolecular Discovery and Design Research Centre, Macquarie University, Sydney, NSW, 2109, Australia.
| | | | - Ian T Paulsen
- Centre of Excellence in Synthetic Biology, Department of Molecular Sciences, Macquarie University, Sydney, NSW, 2109, Australia
- Biomolecular Discovery and Design Research Centre, Macquarie University, Sydney, NSW, 2109, Australia
| | - Helena K M Nevalainen
- Centre of Excellence in Synthetic Biology, Department of Molecular Sciences, Macquarie University, Sydney, NSW, 2109, Australia
- Biomolecular Discovery and Design Research Centre, Macquarie University, Sydney, NSW, 2109, Australia
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Rosales-Calderon O, Arantes V. A review on commercial-scale high-value products that can be produced alongside cellulosic ethanol. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:240. [PMID: 31624502 PMCID: PMC6781352 DOI: 10.1186/s13068-019-1529-1] [Citation(s) in RCA: 138] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 07/17/2019] [Indexed: 05/03/2023]
Abstract
The demand for fossil derivate fuels and chemicals has increased, augmenting concerns on climate change, global economic stability, and sustainability on fossil resources. Therefore, the production of fuels and chemicals from alternative and renewable resources has attracted considerable and growing attention. Ethanol is a promising biofuel that can reduce the consumption of gasoline in the transportation sector and related greenhouse gas (GHG) emissions. Lignocellulosic biomass is a promising feedstock to produce bioethanol (cellulosic ethanol) because of its abundance and low cost. Since the conversion of lignocellulose to ethanol is complex and expensive, the cellulosic ethanol price cannot compete with those of the fossil derivate fuels. A promising strategy to lower the production cost of cellulosic ethanol is developing a biorefinery which produces ethanol and other high-value chemicals from lignocellulose. The selection of such chemicals is difficult because there are hundreds of products that can be produced from lignocellulose. Multiple reviews and reports have described a small group of lignocellulose derivate compounds that have the potential to be commercialized. Some of these products are in the bench scale and require extensive research and time before they can be industrially produced. This review examines chemicals and materials with a Technology Readiness Level (TRL) of at least 8, which have reached a commercial scale and could be shortly or immediately integrated into a cellulosic ethanol process.
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Affiliation(s)
- Oscar Rosales-Calderon
- Department of Biotechnology, Lorena School of Engineering, University of Sao Paulo, Estrada Municipal do Campinho, Lorena, SP CEP 12602-810 Brazil
| | - Valdeir Arantes
- Department of Biotechnology, Lorena School of Engineering, University of Sao Paulo, Estrada Municipal do Campinho, Lorena, SP CEP 12602-810 Brazil
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Singh G, Patel AK, Gupta A, Gupta D, Mishra VK. Current Advancements in Recombinant Technology for Industrial Production of Cellulases: Part-II. Fungal Biol 2019. [DOI: 10.1007/978-3-030-14726-6_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Singhania RR, Patel AK, Pandey A, Ganansounou E. Genetic modification: A tool for enhancing beta-glucosidase production for biofuel application. BIORESOURCE TECHNOLOGY 2017; 245:1352-1361. [PMID: 28596076 DOI: 10.1016/j.biortech.2017.05.126] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/17/2017] [Accepted: 05/19/2017] [Indexed: 05/25/2023]
Abstract
Beta-glucosidase (BGL) is a rate-limiting enzyme for cellulose hydrolysis as it acts in the final step of lignocellulosic biomass conversion to convert cellobiose into glucose, the final end product. Most of the fungal strains used for cellulase production are deficient in BGL hence BGL is supplemented into cellulases to have an efficient biomass conversion. Genetic engineering has enabled strain modification to produce BGL optimally with desired properties to be employed for biofuel applications. It has been cloned either directly into the host strains lacking BGL or into another expression system, to be overexpressed so as to be blended into BGL deficient cellulases. In this article, role of genetic engineering to overcome BGL limitations in the cellulase cocktail and its significance for biofuel applications has been critically reviewed.
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Affiliation(s)
- Reeta Rani Singhania
- DBT-IOC Advanced Bio-Energy Research Centre, Indian Oil Corporation; R&D Centre, Sector-13, Faridabad 121007, India
| | - Anil Kumar Patel
- Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu 96822, HI, United States.
| | - Ashok Pandey
- Center of Innovative and Applied Bioprocessing, Sector 81, Knowledge City PO Manauli, SAS Nagar, Mohali 140306, Punjab, India
| | - Edgard Ganansounou
- Bioenergy and Energy Planning Research Group, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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Panda SK, Ray RC, Mishra SS, Kayitesi E. Microbial processing of fruit and vegetable wastes into potential biocommodities: a review. Crit Rev Biotechnol 2017; 38:1-16. [PMID: 28462596 DOI: 10.1080/07388551.2017.1311295] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The review focuses on some of the high value-end biocommodities, such as fermented beverages, single-cell proteins, single-cell oils, biocolors, flavors, fragrances, polysaccharides, biopesticides, plant growth regulators, bioethanol, biogas and biohydrogen, developed from the microbial processing of fruit and vegetable wastes. Microbial detoxification of fruit and vegetable processing effluents is briefly described. The advances in genetic engineering of microorganisms for enhanced yield of the above-mentioned biocommodities are elucidated with selected examples. The bottleneck in commercialization, integrated approach for improved production, techno-economical feasibility and real-life uses of some of these biocommodities, as well as research gaps and future directions are discussed.
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Affiliation(s)
- Sandeep K Panda
- a Department of Biotechnology and Food Technology, Faculty of Science , University of Johannesburg , Johannesburg , South Africa
| | - Ramesh C Ray
- b Microbiology Research Laboratory, ICAR- Regional Centre of Central Tuber Crops Research Institute , Bhubaneswar , India
| | - Swati S Mishra
- c Department of Biodiversity and Conservation of Natural Resources , Central University of Orissa , Koraput , India
| | - Eugenie Kayitesi
- a Department of Biotechnology and Food Technology, Faculty of Science , University of Johannesburg , Johannesburg , South Africa
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Singh G, Verma AK, Kumar V. Catalytic properties, functional attributes and industrial applications of β-glucosidases. 3 Biotech 2016; 6:3. [PMID: 28330074 PMCID: PMC4697909 DOI: 10.1007/s13205-015-0328-z] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 06/19/2015] [Indexed: 12/18/2022] Open
Abstract
β-Glucosidases are diverse group of enzymes with great functional importance to biological systems. These are grouped in multiple glycoside hydrolase families based on their catalytic and sequence characteristics. Most studies carried out on β-glucosidases are focused on their industrial applications rather than their endogenous function in the target organisms. β-Glucosidases performed many functions in bacteria as they are components of large complexes called cellulosomes and are responsible for the hydrolysis of short chain oligosaccharides and cellobiose. In plants, β-glucosidases are involved in processes like formation of required intermediates for cell wall lignification, degradation of endosperm’s cell wall during germination and in plant defense against biotic stresses. Mammalian β-glucosidases are thought to play roles in metabolism of glycolipids and dietary glucosides, and signaling functions. These enzymes have diverse biotechnological applications in food, surfactant, biofuel, and agricultural industries. The search for novel and improved β-glucosidase is still continued to fulfills demand of an industrially suitable enzyme. In this review, a comprehensive overview on detailed functional roles of β-glucosidases in different organisms, their industrial applications, and recent cloning and expression studies with biochemical characterization of such enzymes is presented for the better understanding and efficient use of diverse β-glucosidases.
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Affiliation(s)
- Gopal Singh
- Institute of Himalayan Bioresource Technology, Palampur, 176062, India
| | - A K Verma
- Department of Biochemistry, College of Basic Sciences and Humanities, G. B. Pant University of Agriculture and Technology, Pantnagar, 263145, India
| | - Vinod Kumar
- Department of Biotechnology, Akal College of Agriculture, Eternal University, Baru Sahib, Sirmour, 173101, India.
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Larue K, Melgar M, Martin VJJ. Directed evolution of a fungal β-glucosidase in Saccharomyces cerevisiae. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:52. [PMID: 26949413 PMCID: PMC4778352 DOI: 10.1186/s13068-016-0470-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/22/2016] [Indexed: 05/13/2023]
Abstract
BACKGROUND β-glucosidases (BGLs) catalyze the hydrolysis of soluble cellodextrins to glucose and are a critical component of cellulase systems. In order to engineer Saccharomyces cerevisiae for the production of ethanol from cellulosic biomass, a BGL tailored to industrial bioconversions is needed. RESULTS We applied a directed evolution strategy to a glycosyl hydrolase family 3 (GH3) BGL from Aspergillus niger (BGL1) by expressing a library of mutated bgl1 genes in S. cerevisiae and used a two-step functional screen to identify improved enzymes. Twelve BGL variants that supported growth of S. cerevisiae on cellobiose and showed increased activity on the synthetic substrate p-nitrophenyl-β-D-glucopyranoside were identified and characterized. By performing kinetic experiments, we found that a Tyr → Cys substitution at position 305 of BGL1 dramatically reduced transglycosidation activity that causes inhibition of the hydrolytic reaction at high substrate concentrations. Targeted mutagenesis demonstrated that the position 305 residue is critical in GH3 BGLs and likely determines the extent to which transglycosidation reactions occur. We also found that a substitution at Gln(140) reduced the inhibitory effect of glucose and could be combined with the Y305C substitution to produce a BGL with decreased sensitivity to both the product and substrate. Using the crystal structure of a GH3 BGL from A. aculeatus, we mapped a group of beneficial mutations to the β/α domain of the molecule and postulate that this region modulates activity through subunit interactions. Six BGL variants were identified with substitutions in the MFα pre-sequence that was used to mediate secretion of the protein. Substitutions at Pro(21) or Val(22) of the MFα pre-sequence could produce up to a twofold increase in supernatant hydrolase activity and provides evidence that expression and/or secretion was an additional factor limiting hydrolytic activity. CONCLUSIONS Using directed evolution on BGL1, we identified a key residue that controls hydrolytic and transglycosidation reactions in GH3 BGLs. We also found that several beneficial mutations could be combined and increased the hydrolytic activity for both synthetic and natural substrates.
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Affiliation(s)
- Kane Larue
- Department of Biology, Centre for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke West, Montreal, QC H4B 1R6 Canada
| | - Mindy Melgar
- Department of Biology, Centre for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke West, Montreal, QC H4B 1R6 Canada
| | - Vincent J. J. Martin
- Department of Biology, Centre for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke West, Montreal, QC H4B 1R6 Canada
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de Amorim Araújo J, Ferreira TC, Rubini MR, Duran AGG, De Marco JL, de Moraes LMP, Torres FAG. Coexpression of cellulases in Pichia pastoris as a self-processing protein fusion. AMB Express 2015; 5:84. [PMID: 26698316 PMCID: PMC4689727 DOI: 10.1186/s13568-015-0170-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 12/11/2015] [Indexed: 02/06/2023] Open
Abstract
The term cellulase refers to any component of the enzymatic complex produced by some fungi, bacteria and protozoans which act serially or synergistically to catalyze the cleavage of cellulosic materials. Cellulases have been widely used in many industrial applications ranging from food industry to the production of second generation ethanol. In an effort to develop new strategies to minimize the costs of enzyme production we describe the development of a Pichia pastoris strain able to coproduce two different cellulases. For that purpose the eglII (endoglucanase II) and cbhII (cellobiohydrolase II) genes from Trichoderma reesei were fused in-frame separated by the self-processing 2A peptide sequence from the foot-and-mouth disease virus. The protein fusion construct was placed under the control of the strong inducible AOX1 promoter. Analysis of culture supernatants from methanol-induced yeast transformants showed that the protein fusion was effectively processed. Enzymatic assay showed that the processed enzymes were fully functional with the same catalytic properties of the individual enzymes produced separately. Furthermore, when combined both enzymes acted synergistically on filter paper to produce cellobiose as the main end-product. Based on these results we propose that P. pastoris should be considered as an alternative platform for the production of cellulases at competitive costs.
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Bhattacharya AS, Bhattacharya A, Pletschke BI. Synergism of fungal and bacterial cellulases and hemicellulases: a novel perspective for enhanced bio-ethanol production. Biotechnol Lett 2015; 37:1117-29. [DOI: 10.1007/s10529-015-1779-3] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 01/21/2015] [Indexed: 12/15/2022]
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Guo Z, Duquesne S, Bozonnet S, Cioci G, Nicaud JM, Marty A, O’Donohue MJ. Development of cellobiose-degrading ability in Yarrowia lipolytica strain by overexpression of endogenous genes. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:109. [PMID: 26244054 PMCID: PMC4524412 DOI: 10.1186/s13068-015-0289-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 07/22/2015] [Indexed: 05/03/2023]
Abstract
BACKGROUND Yarrowia lipolytica, one of the most widely studied "nonconventional" oleaginous yeast species, is unable to grow on cellobiose. Engineering cellobiose-degrading ability into this yeast is a vital step towards the development of cellulolytic biocatalysts suitable for consolidated bioprocessing. RESULTS In the present work, we identified six genes encoding putative β-glucosidases in the Y. lipolytica genome. To study these, homologous expression was attempted in Y. lipolytica JMY1212 Zeta. Two strains overexpressing BGL1 (YALI0F16027g) and BGL2 (YALI0B14289g) produced β-glucosidase activity and were able to degrade cellobiose, while the other four did not display any detectable activity. The two active β-glucosidases, one of which was mainly cell-associated while the other was present in the extracellular medium, were purified and characterized. The two Bgls were most active at 40-45°C and pH 4.0-4.5, and exhibited hydrolytic activity on various β-glycoside substrates. Specifically, Bgl1 displayed 12.5-fold higher catalytic efficiency on cellobiose than Bgl2. Significantly, in experiments where cellobiose or cellulose (performed in the presence of a β-glucosidase-deficient commercial cellulase cocktail produced by Trichoderma reseei) was used as carbon source for aerobic cultivation, Y. lipolytica ∆pox co-expressing BGL1 and BGL2 grew better than the Y. lipolytica strains expressing single BGLs. The specific growth rate and biomass yield of Y. lipolytica JMY1212 co-expressing BGL1 and BGL2 were 0.15 h(-1) and 0.50 g-DCW/g-cellobiose, respectively, similar to that of the control grown on glucose. CONCLUSIONS We conclude that the bi-functional Y. lipolytica developed in the current study represents a vital step towards the creation of a cellulolytic yeast strain that can be used for lipid production from lignocellulosic biomass. When used in combination with commercial cellulolytic cocktails, this strain will no doubt reduce enzyme requirements and thus costs.
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Affiliation(s)
- Zhongpeng Guo
- />LISBP-Biocatalysis Group, INSA/INRA UMR 792, Université de Toulouse, 135 Avenue de Rangueil, 31077 Toulouse, France
- />INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, 31400 Toulouse, France
- />CNRS, UMR5504, 31400 Toulouse, France
| | - Sophie Duquesne
- />LISBP-Biocatalysis Group, INSA/INRA UMR 792, Université de Toulouse, 135 Avenue de Rangueil, 31077 Toulouse, France
- />INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, 31400 Toulouse, France
- />CNRS, UMR5504, 31400 Toulouse, France
| | - Sophie Bozonnet
- />LISBP-Biocatalysis Group, INSA/INRA UMR 792, Université de Toulouse, 135 Avenue de Rangueil, 31077 Toulouse, France
- />INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, 31400 Toulouse, France
- />CNRS, UMR5504, 31400 Toulouse, France
| | - Gianluca Cioci
- />LISBP-Biocatalysis Group, INSA/INRA UMR 792, Université de Toulouse, 135 Avenue de Rangueil, 31077 Toulouse, France
- />INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, 31400 Toulouse, France
- />CNRS, UMR5504, 31400 Toulouse, France
| | - Jean-Marc Nicaud
- />INRA, UMR1319 Micalis, 78352 Jouy-en-Josas, France
- />AgroParisTech, UMR Micalis, 78352 Jouy-en-Josas, France
| | - Alain Marty
- />LISBP-Biocatalysis Group, INSA/INRA UMR 792, Université de Toulouse, 135 Avenue de Rangueil, 31077 Toulouse, France
- />INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, 31400 Toulouse, France
- />CNRS, UMR5504, 31400 Toulouse, France
| | - Michael Joseph O’Donohue
- />LISBP-Biocatalysis Group, INSA/INRA UMR 792, Université de Toulouse, 135 Avenue de Rangueil, 31077 Toulouse, France
- />INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, 31400 Toulouse, France
- />CNRS, UMR5504, 31400 Toulouse, France
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Kim SJ, Hyeon JE, Jeon SD, Choi GW, Han SO. Bi-functional cellulases complexes displayed on the cell surface of Corynebacterium glutamicum increase hydrolysis of lignocelluloses at elevated temperature. Enzyme Microb Technol 2014; 66:67-73. [PMID: 25248702 DOI: 10.1016/j.enzmictec.2014.08.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 08/20/2014] [Accepted: 08/22/2014] [Indexed: 12/11/2022]
Abstract
Introducing cellulases into Corynebacterium glutamicum leads to the direct degradation of lignocellulosic materials for energy sources. In this study, a cellulase complex containing two cellulolytic enzymes, endoglucanase E (CelE) and β-glucosidase A (BglA), was established to completely degrade cellulose to glucose. The cellulases complexes were displayed on the cell surface of C. glutamicum by using the mechanosensitive channel (Msc) to anchor enzymes in the cytoplasmic membrane. As confirmed by comparison enzyme activities in the cell pellet fraction and supernatant and dual color based immunofluorescence microscopy, the cellulolytic enzymes was successfully associated with the cell surface of C. glutamicum. The displayed cellulases complexes had a synergic effect on the direct conversion of biomass to reducing sugars leading to 3.1- to 6.0-fold increase compared to the conversion by the secreted cellulases complexes. In addition, the displayed cellulases complexes increased the residual activities of cCelE and cBglA at 70°C from 28.3% and 24.3% in the secreted form to 65.1% and 82.8%, respectively. The display of cellulases complexes on the cell surface of C. glutamicum enhances the polysaccharide equivalent and the direct saccharification of low cost biomass via the action of multi-thermostable enzyme complexes.
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Affiliation(s)
- Su Jung Kim
- Department of Biotechnology, Korea University, Seoul 136-701, Republic of Korea
| | - Jeong Eun Hyeon
- Department of Biotechnology, Korea University, Seoul 136-701, Republic of Korea
| | - Sang Duck Jeon
- Department of Biotechnology, Korea University, Seoul 136-701, Republic of Korea
| | - Gi-wook Choi
- Changhae Advanced Institute of Technology, Changhae Ethanol C., Ltd., Jeonju 561-203, Republic of Korea
| | - Sung Ok Han
- Department of Biotechnology, Korea University, Seoul 136-701, Republic of Korea.
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Hyeon JE, You SK, Kang DH, Ryu SH, Kim M, Lee SS, Han SO. Enzymatic degradation of lignocellulosic biomass by continuous process using laccase and cellulases with the aid of scaffoldin for ethanol production. Process Biochem 2014. [DOI: 10.1016/j.procbio.2014.05.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Hyeon JE, Jeon SD, Han SO. Cellulosome-based, Clostridium-derived multi-functional enzyme complexes for advanced biotechnology tool development: advances and applications. Biotechnol Adv 2013; 31:936-44. [PMID: 23563098 DOI: 10.1016/j.biotechadv.2013.03.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 03/22/2013] [Accepted: 03/25/2013] [Indexed: 12/20/2022]
Abstract
The cellulosome is one of nature's most elegant and elaborate nanomachines and a key biological and biotechnological macromolecule that can be used as a multi-functional protein complex tool. Each protein module in the cellulosome system is potentially useful in an advanced biotechnology application. The high-affinity interactions between the cohesin and dockerin domains can be used in protein-based biosensors to improve both sensitivity and selectivity. The scaffolding protein includes a carbohydrate-binding module (CBM) that attaches strongly to cellulose substrates and facilitates the purification of proteins fused with the dockerin module through a one-step CBM purification method. Although the surface layer homology (SLH) domain of CbpA is not present in other strains, replacement of the cell surface anchoring domain allows a foreign protein to be displayed on the surface of other strains. The development of a hydrolysis enzyme complex is a useful strategy for consolidated bioprocessing (CBP), enabling microorganisms with biomass hydrolysis activity. Thus, the development of various configurations of multi-functional protein complexes for use as tools in whole-cell biocatalyst systems has drawn considerable attention as an attractive strategy for bioprocess applications. This review provides a detailed summary of the current achievements in Clostridium-derived multi-functional complex development and the impact of these complexes in various areas of biotechnology.
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Affiliation(s)
- Jeong Eun Hyeon
- School of Life Sciences and Biotechnology, Korea University, Seoul, 136-701, Republic of Korea
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Unique contribution of the cell wall-binding endoglucanase G to the cellulolytic complex in Clostridium cellulovorans. Appl Environ Microbiol 2013; 79:5942-8. [PMID: 23872560 DOI: 10.1128/aem.01400-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The cellulosomes produced by Clostridium cellulovorans are organized by the specific interactions between the cohesins in the scaffolding proteins and the dockerins of the catalytic components. Using a cohesin biomarker, we identified a cellulosomal enzyme which belongs to the glycosyl hydrolase family 5 and has a domain of unknown function 291 (DUF291) with functions similar to those of the surface layer homology domain in C. cellulovorans. The purified endoglucanase G (EngG) had the highest synergistic degree with exoglucanase (ExgS) in the hydrolysis of crystalline cellulose (EngG/ExgS ratio = 3:1; 1.71-fold). To measure the binding affinity of the dockerins in EngG for the cohesins of the main scaffolding protein, a competitive enzyme-linked interaction assay was performed. Competitors, such as ExgS, reduced the percentage of EngG that were bound to the cohesins to less than 20%; the results demonstrated that the cohesins prefer to bind to the common cellulosomal enzymes rather than to EngG. Additionally, in surface plasmon resonance analysis, the dockerin in EngG had a relatively weak affinity (30- to 123-fold) for cohesins compared with the other cellulosomal enzymes. In the cell wall affinity assay, EngG anchored to the cell surfaces of C. cellulovorans using its DUF291 domain. Immunofluorescence microscopy confirmed the cell surface display of the EngG complex. These results indicated that in C. cellulovorans, EngG assemble into both the cellulolytic complex and the cell wall complex to aid in the hydrolysis of cellulose substrates.
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Singhania RR, Patel AK, Sukumaran RK, Larroche C, Pandey A. Role and significance of beta-glucosidases in the hydrolysis of cellulose for bioethanol production. BIORESOURCE TECHNOLOGY 2013; 127:500-7. [PMID: 23069613 DOI: 10.1016/j.biortech.2012.09.012] [Citation(s) in RCA: 321] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 09/05/2012] [Accepted: 09/05/2012] [Indexed: 05/02/2023]
Abstract
One of the major challenges in the bioconversion of lignocellulosic biomass into liquid biofuels includes the search for a glucose tolerant beta-gulucosidase. Beta-glucosidase is the key enzyme component present in cellulase and completes the final step during cellulose hydrolysis by converting the cellobiose to glucose. This reaction is always under control as it gets inhibited by its product glucose. It is a major bottleneck in the efficient biomass conversion by cellulase. To circumvent this problem several strategies have been adopted which we have discussed in the article along with its production strategies and general properties. It plays a very significant role in bioethanol production from biomass through enzymatic route. Hence several amendments took place in the commercial preparation of cellulase for biomass hydrolysis, which contains higher and improved beta-glucosidase for efficient biomass conversion. This article presents beta-glucosidase as the key component for bioethanol from biomass through enzymatic route.
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Affiliation(s)
- Reeta Rani Singhania
- Laboratoire de Génie Chimique et Biochimique, Université Blaise Pascal, Polytech Clermont-Ferrand, Aubiere cedex, France.
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17
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Lin H, Wang Q, Shen Q, Zhan J, Zhao Y. Genetic engineering of microorganisms for biodiesel production. Bioengineered 2012; 4:292-304. [PMID: 23222170 DOI: 10.4161/bioe.23114] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Biodiesel, as one type of renewable energy, is an ideal substitute for petroleum-based diesel fuel and is usually made from triacylglycerides by transesterification with alcohols. Biodiesel production based on microbial fermentation aiming to establish more efficient, less-cost and sustainable biodiesel production strategies is under current investigation by various start-up biotechnology companies and research centers. Genetic engineering plays a key role in the transformation of microbes into the desired cell factories with high efficiency of biodiesel production. Here, we present an overview of principal microorganisms used in the microbial biodiesel production and recent advances in metabolic engineering for the modification required. Overexpression or deletion of the related enzymes for de novo synthesis of biodiesel is highlighted with relevant examples.
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Affiliation(s)
- Hui Lin
- Institute of Microbiology; College of Life Sciences; Zhejiang University; Hangzhou, China; Institute of Plant Science; College of Life Sciences; Zhejiang University; Hangzhou, China
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Baek SH, Kim S, Lee K, Lee JK, Hahn JS. Cellulosic ethanol production by combination of cellulase-displaying yeast cells. Enzyme Microb Technol 2012; 51:366-72. [PMID: 23040393 DOI: 10.1016/j.enzmictec.2012.08.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 08/06/2012] [Accepted: 08/10/2012] [Indexed: 10/28/2022]
Abstract
As an effort to find suitable endoglucanases to generate cellulolytic yeast strains, two fungal endoglucanases, Thermoascus aurantiacus EGI and Trichoderma reesei EGII, and two bacterial endoglucanases, Clostridium thermocellum CelA and CelD, were expressed on the yeast surface, and their surface expression levels, pH- and temperature-dependent enzyme activities, and substrate specificities were analyzed. T. aurantiacus EGI showed similar patterns of pH- and temperature-dependent activities to those of T. reesei EGII which has been widely used due to its high enzyme activity. Although EGII showed higher carboxymethyl cellulose (CMC) degradation activity than EGI, EGI showed better activity toward phosphoric acid swollen cellulose (PASC). For ethanol production from PASC, we combined three types of yeast cells, each displaying T. aurantiacus EGI, T. reesei CBHII (exoglucanase) and Aspergillus aculeatus BGLI (β-glucosidase), instead of co-expressing these enzymes in a single cell. In this system, ethanol production can be easily optimized by adjusting the combination ratio of each cell type. A mixture of cells with the optimized EGI:CBHII:BGLI ratio of 6:2:1 produced 1.3 fold more ethanol (2.1g/l) than cells composed of an equal amount of each cell type, suggesting the usefulness of this system for cellulosic ethanol production.
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Affiliation(s)
- Seung-Ho Baek
- School of Chemical and Biological Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-744, Republic of Korea
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Taylor MP, Mulako I, Tuffin M, Cowan D. Understanding physiological responses to pre-treatment inhibitors in ethanologenic fermentations. Biotechnol J 2012; 7:1169-81. [PMID: 22331581 DOI: 10.1002/biot.201100335] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 12/15/2011] [Accepted: 01/17/2012] [Indexed: 11/10/2022]
Abstract
Alcohol-based liquid fuels feature significantly in the political and social agendas of many countries, seeking energy sustainability. It is certain that ethanol will be the entry point for many sustainable processes. Conventional ethanol production using maize- and sugarcane-based carbohydrates with Saccharomyces cerevisiae is well established, while lignocellulose-based processes are receiving growing interest despite posing greater technical and scientific challenges. A significant challenge that arises from the chemical hydrolysis of lignocellulose is the generation of toxic compounds in parallel with the release of sugars. These compounds, collectively termed pre-treatment inhibitors, impair metabolic functionality and growth. Their removal, pre-fermentation or their abatement, via milder hydrolysis, are currently uneconomic options. It is widely acknowledged that a more cost effective strategy is to develop resistant process strains. Here we describe and classify common inhibitors and describe in detail the reported physiological responses that occur in second-generation strains, which include engineered yeast and mesophilic and thermophilic prokaryotes. It is suggested that a thorough understanding of tolerance to common pre-treatment inhibitors should be a major focus in ongoing strain engineering. This review is a useful resource for future metabolic engineering strategies.
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Affiliation(s)
- Mark P Taylor
- TMO Renewables Ltd., The Surrey Research Park, Guildford, UK
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20
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Jeon SD, Yu KO, Kim SW, Han SO. The processive endoglucanase EngZ is active in crystalline cellulose degradation as a cellulosomal subunit of Clostridium cellulovorans. N Biotechnol 2012; 29:365-71. [DOI: 10.1016/j.nbt.2011.06.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 05/17/2011] [Accepted: 06/01/2011] [Indexed: 10/18/2022]
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21
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Wilde C, Gold ND, Bawa N, Tambor JHM, Mougharbel L, Storms R, Martin VJJ. Expression of a library of fungal β-glucosidases in Saccharomyces cerevisiae for the development of a biomass fermenting strain. Appl Microbiol Biotechnol 2012; 95:647-59. [DOI: 10.1007/s00253-011-3788-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Revised: 11/21/2011] [Accepted: 11/23/2011] [Indexed: 10/14/2022]
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Goyal G, Tsai SL, Madan B, DaSilva NA, Chen W. Simultaneous cell growth and ethanol production from cellulose by an engineered yeast consortium displaying a functional mini-cellulosome. Microb Cell Fact 2011; 10:89. [PMID: 22044771 PMCID: PMC3219590 DOI: 10.1186/1475-2859-10-89] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 11/01/2011] [Indexed: 12/04/2022] Open
Abstract
Background The recalcitrant nature of cellulosic materials and the high cost of enzymes required for efficient hydrolysis are the major impeding steps to their practical usage for ethanol production. Ideally, a recombinant microorganism, possessing the capability to utilize cellulose for simultaneous growth and ethanol production, is of great interest. We have reported recently the use of a yeast consortium for the functional presentation of a mini-cellulosome structure onto the yeast surface by exploiting the specific interaction of different cohesin-dockerin pairs. In this study, we engineered a yeast consortium capable of displaying a functional mini-cellulosome for the simultaneous growth and ethanol production on phosphoric acid swollen cellulose (PASC). Results A yeast consortium composed of four different populations was engineered to display a functional mini-cellulosome containing an endoglucanase, an exoglucanase and a β-glucosidase. The resulting consortium was demonstrated to utilize PASC for growth and ethanol production. The final ethanol production of 1.25 g/L corresponded to 87% of the theoretical value and was 3-fold higher than a similar yeast consortium secreting only the three cellulases. Quantitative PCR was used to enumerate the dynamics of each individual yeast population for the two consortia. Results indicated that the slight difference in cell growth cannot explain the 3-fold increase in PASC hydrolysis and ethanol production. Instead, the substantial increase in ethanol production is consistent with the reported synergistic effect on cellulose hydrolysis using the displayed mini-cellulosome. Conclusions This report represents a significant step towards the goal of cellulosic ethanol production. This engineered yeast consortium displaying a functional mini-cellulosome demonstrated not only the ability to grow on the released sugars from PASC but also a 3-fold higher ethanol production than a similar yeast consortium secreting only the three cellulases. The use of more complex cellulosomal structures may further improve the overall efficiency for ethanol production.
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Affiliation(s)
- Garima Goyal
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, USA
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van Zyl WH, Chimphango AFA, den Haan R, Görgens JF, Chirwa PWC. Next-generation cellulosic ethanol technologies and their contribution to a sustainable Africa. Interface Focus 2011; 1:196-211. [PMID: 22482027 PMCID: PMC3262263 DOI: 10.1098/rsfs.2010.0017] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Accepted: 01/12/2011] [Indexed: 11/12/2022] Open
Abstract
The world is currently heavily dependent on oil, especially in the transport sector. However, rising oil prices, concern about environmental impact and supply instability are among the factors that have led to greater interest in renewable fuel and green chemistry alternatives. Lignocellulose is the only foreseeable renewable feedstock for sustainable production of transport fuels. The main technological impediment to more widespread utilization of lignocellulose for production of fuels and chemicals in the past has been the lack of low-cost technologies to overcome the recalcitrance of its structure. Both biological and thermochemical second-generation conversion technologies are currently coming online for the commercial production of cellulosic ethanol concomitantly with heat and electricity production. The latest advances in biological conversion of lignocellulosics to ethanol with a focus on consolidated bioprocessing are highlighted. Furthermore, integration of cellulosic ethanol production into existing bio-based industries also using thermochemical processes to optimize energy balances is discussed. Biofuels have played a pivotal yet suboptimal role in supplementing Africa's energy requirements in the past. Capitalizing on sub-Saharan Africa's total biomass potential and using second-generation technologies merit a fresh look at the potential role of bioethanol production towards developing a sustainable Africa while addressing food security, human needs and local wealth creation.
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Affiliation(s)
- W. H. van Zyl
- Department of Microbiology, University of Stellenbosch, De Beer Street, Stellenbosch 7600, South Africa
| | - A. F. A. Chimphango
- Department of Process Engineering, University of Stellenbosch, De Beer Street, Stellenbosch 7600, South Africa
| | - R. den Haan
- Department of Microbiology, University of Stellenbosch, De Beer Street, Stellenbosch 7600, South Africa
| | - J. F. Görgens
- Department of Process Engineering, University of Stellenbosch, De Beer Street, Stellenbosch 7600, South Africa
| | - P. W. C. Chirwa
- Forest Science Postgraduate Programme, University of Pretoria, Pretoria 0002, South Africa
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Jeon SD, Yu KO, Kim SW, Han SO. A celluloytic complex from Clostridium cellulovorans consisting of mannanase B and endoglucanase E has synergistic effects on galactomannan degradation. Appl Microbiol Biotechnol 2011; 90:565-72. [DOI: 10.1007/s00253-011-3108-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 12/30/2010] [Accepted: 01/05/2011] [Indexed: 10/18/2022]
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Madhavan A, Srivastava A, Kondo A, Bisaria VS. Bioconversion of lignocellulose-derived sugars to ethanol by engineered Saccharomyces cerevisiae. Crit Rev Biotechnol 2011; 32:22-48. [PMID: 21204601 DOI: 10.3109/07388551.2010.539551] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Lignocellulosic biomass from agricultural and agro-industrial residues represents one of the most important renewable resources that can be utilized for the biological production of ethanol. The yeast Saccharomyces cerevisiae is widely used for the commercial production of bioethanol from sucrose or starch-derived glucose. While glucose and other hexose sugars like galactose and mannose can be fermented to ethanol by S. cerevisiae, the major pentose sugars D-xylose and L-arabinose remain unutilized. Nevertheless, D-xylulose, the keto isomer of xylose, can be fermented slowly by the yeast and thus, the incorporation of functional routes for the conversion of xylose and arabinose to xylulose or xylulose-5-phosphate in Saccharomyces cerevisiae can help to improve the ethanol productivity and make the fermentation process more cost-effective. Other crucial bottlenecks in pentose fermentation include low activity of the pentose phosphate pathway enzymes and competitive inhibition of xylose and arabinose transport into the cell cytoplasm by glucose and other hexose sugars. Along with a brief introduction of the pretreatment of lignocellulose and detoxification of the hydrolysate, this review provides an updated overview of (a) the key steps involved in the uptake and metabolism of the hexose sugars: glucose, galactose, and mannose, together with the pentose sugars: xylose and arabinose, (b) various factors that play a major role in the efficient fermentation of pentose sugars along with hexose sugars, and (c) the approaches used to overcome the metabolic constraints in the production of bioethanol from lignocellulose-derived sugars by developing recombinant S. cerevisiae strains.
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Affiliation(s)
- Anjali Madhavan
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
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Elkins JG, Raman B, Keller M. Engineered microbial systems for enhanced conversion of lignocellulosic biomass. Curr Opin Biotechnol 2010; 21:657-62. [DOI: 10.1016/j.copbio.2010.05.008] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Accepted: 05/27/2010] [Indexed: 11/16/2022]
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la Grange DC, den Haan R, van Zyl WH. Engineering cellulolytic ability into bioprocessing organisms. Appl Microbiol Biotechnol 2010; 87:1195-208. [DOI: 10.1007/s00253-010-2660-x] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 05/02/2010] [Accepted: 05/02/2010] [Indexed: 10/19/2022]
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28
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Current awareness on yeast. Yeast 2010. [DOI: 10.1002/yea.1717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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