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Ma XY, Coleman B, Prabhu P, Yang M, Wen F. Engineering Compositionally Uniform Yeast Whole-Cell Biocatalysts with Maximized Surface Enzyme Density for Cellulosic Biofuel Production. ACS Synth Biol 2024; 13:1225-1236. [PMID: 38551819 DOI: 10.1021/acssynbio.3c00669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
In recent decades, whole-cell biocatalysis has played an increasingly important role in the food, pharmaceutical, and energy sector. One promising application is the use of ethanologenic yeast displaying minicellulosomes on the cell surface to combine cellulose hydrolysis and fermentation into a single step for consolidated bioprocessing. However, cellulosic ethanol production using existing yeast whole-cell biocatalysts (yWCBs) has not reached industrial feasibility due to their inefficient cellulose hydrolysis. As prior studies have demonstrated enzyme density on the yWCB surface to be one of the most important parameters for enhancing cellulose hydrolysis, we sought to maximize this parameter at both the population and single-cell levels in yWCBs displaying tetrafunctional minicellulosomes. At the population level, enzyme density is limited by the presence of a nondisplay population constituting 25-50% of all cells. In this study, we identified the cause to be plasmid loss and successfully eliminated the nondisplay population to generate compositionally uniform yWCBs. At the single-cell level, we demonstrate that enzyme density is limited by molecular crowding, which hinders minicellulosome assembly. By adjusting the integrated gene copy number, we obtained yWCBs of tunable enzyme display levels. This tunability allowed us to avoid the crowding-limited regime and achieve a maximum enzyme density per cell. As a result, the best strain showed a cellulose-to-ethanol yield of 4.92 g/g, corresponding to 96% of the theoretical maximum and near-complete conversion (∼96%) of the starting cellulose (1% PASC). Our holistic engineering strategy that combines a population and single-cell level approach is broadly applicable to enhance the WCB performance in other biocatalytic cascade schemes.
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Affiliation(s)
- Xiao Yin Ma
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Catalysis Science and Technology Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Bryan Coleman
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Catalysis Science and Technology Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Ponnandy Prabhu
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Margaret Yang
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Fei Wen
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Catalysis Science and Technology Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
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Muñoz-Muñoz PLA, Terán-Ramírez C, Mares-Alejandre RE, Márquez-González AB, Madero-Ayala PA, Meléndez-López SG, Ramos-Ibarra MA. Surface Engineering of Escherichia coli to Display Its Phytase (AppA) and Functional Analysis of Enzyme Activities. Curr Issues Mol Biol 2024; 46:3424-3437. [PMID: 38666945 PMCID: PMC11048855 DOI: 10.3390/cimb46040215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 04/11/2024] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
Escherichia coli phytase (AppA) is widely used as an exogenous enzyme in monogastric animal feed mainly because of its ability to degrade phytic acid or its salt (phytate), a natural source of phosphorus. Currently, successful recombinant production of soluble AppA has been achieved by gene overexpression using both bacterial and yeast systems. However, some methods for the biomembrane immobilization of phytases (including AppA), such as surface display on yeast cells and bacterial spores, have been investigated to avoid expensive enzyme purification processes. This study explored a homologous protein production approach for displaying AppA on the cell surface of E. coli by engineering its outer membrane (OM) for extracellular expression. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of total bacterial lysates and immunofluorescence microscopy of non-permeabilized cells revealed protein expression, whereas activity assays using whole cells or OM fractions indicated functional enzyme display, as evidenced by consistent hydrolytic rates on typical substrates (i.e., p-nitrophenyl phosphate and phytic acid). Furthermore, the in vitro results obtained using a simple method to simulate the gastrointestinal tract of poultry suggest that the whole-cell biocatalyst has potential as a feed additive. Overall, our findings support the notion that biomembrane-immobilized enzymes are reliable for the hydrolysis of poorly digestible substrates relevant to animal nutrition.
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Affiliation(s)
- Patricia L. A. Muñoz-Muñoz
- Biotechnology and Biosciences Research Group, School of Chemical Sciences and Engineering, Autonomous University of Baja California, Tijuana 22390, BCN, Mexico; (P.L.A.M.-M.); (C.T.-R.); (R.E.M.-A.); (A.B.M.-G.); (P.A.M.-A.); (S.G.M.-L.)
| | - Celina Terán-Ramírez
- Biotechnology and Biosciences Research Group, School of Chemical Sciences and Engineering, Autonomous University of Baja California, Tijuana 22390, BCN, Mexico; (P.L.A.M.-M.); (C.T.-R.); (R.E.M.-A.); (A.B.M.-G.); (P.A.M.-A.); (S.G.M.-L.)
- Biochemical Sciences Graduate Program (Doctorate Studies), National Autonomous University of Mexico, Cuernavaca 62210, MOR, Mexico
| | - Rosa E. Mares-Alejandre
- Biotechnology and Biosciences Research Group, School of Chemical Sciences and Engineering, Autonomous University of Baja California, Tijuana 22390, BCN, Mexico; (P.L.A.M.-M.); (C.T.-R.); (R.E.M.-A.); (A.B.M.-G.); (P.A.M.-A.); (S.G.M.-L.)
| | - Ariana B. Márquez-González
- Biotechnology and Biosciences Research Group, School of Chemical Sciences and Engineering, Autonomous University of Baja California, Tijuana 22390, BCN, Mexico; (P.L.A.M.-M.); (C.T.-R.); (R.E.M.-A.); (A.B.M.-G.); (P.A.M.-A.); (S.G.M.-L.)
- Biological and Biomedical Sciences Graduate Program (Doctorate Studies), University of North Carolina, Chapel Hill, NC 27599, USA
| | - Pablo A. Madero-Ayala
- Biotechnology and Biosciences Research Group, School of Chemical Sciences and Engineering, Autonomous University of Baja California, Tijuana 22390, BCN, Mexico; (P.L.A.M.-M.); (C.T.-R.); (R.E.M.-A.); (A.B.M.-G.); (P.A.M.-A.); (S.G.M.-L.)
- Science and Engineering Graduate Program (Doctorate Studies), Autonomous University of Baja California, Tijuana 22390, BCN, Mexico
| | - Samuel G. Meléndez-López
- Biotechnology and Biosciences Research Group, School of Chemical Sciences and Engineering, Autonomous University of Baja California, Tijuana 22390, BCN, Mexico; (P.L.A.M.-M.); (C.T.-R.); (R.E.M.-A.); (A.B.M.-G.); (P.A.M.-A.); (S.G.M.-L.)
| | - Marco A. Ramos-Ibarra
- Biotechnology and Biosciences Research Group, School of Chemical Sciences and Engineering, Autonomous University of Baja California, Tijuana 22390, BCN, Mexico; (P.L.A.M.-M.); (C.T.-R.); (R.E.M.-A.); (A.B.M.-G.); (P.A.M.-A.); (S.G.M.-L.)
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Overexpression of LAS21 in Cellulase-Displaying Saccharomyces cerevisiae for High-Yield Ethanol Production from Pretreated Sugarcane Bagasse. FERMENTATION-BASEL 2022. [DOI: 10.3390/fermentation8110652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The valorization of lignocellulosic feedstocks into biofuels and biochemicals has received much attention due to its environmental friendliness and sustainability. However, engineering an ideal microorganism that can both produce sufficient cellulases and ferment ethanol is highly challenging. In this study, we have tested seven different genes that are involved in glycosylphosphatidylinositol (GPI) biosynthesis and remodeling for the improvement of cellulase activity tethered on the S. cerevisiae cell surface. It was found that the overexpression of LAS21 can improve β-glucosidase activity by 48.8% compared to the original strain. Then, the three cellulase genes (cellobiohydrolase, endoglucanase, and β-glucosidase) and the LAS21 gene were co-introduced into a diploid thermotolerant S. cerevisiae strain by a multiple-round transformation approach, resulting in the cellulolytic ECBLCCE5 strain. Further optimization of the bioprocess parameters was found to enhance the ethanol yield of the ECBLCCE5 strain. Scaling up the valorization of pretreated sugarcane bagasses in a 1 L bioreactor resulted in a maximum ethanol concentration of 28.0 g/L (86.5% of theoretical yield). Our study provides a promising way to improve the economic viability of second-generation ethanol production. Moreover, the engineering of genes involved in GPI biosynthesis and remodeling can be applied to other yeast cell surface display applications.
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Dhakal S, Macreadie I. The Use of Yeast in Biosensing. Microorganisms 2022; 10:microorganisms10091772. [PMID: 36144374 PMCID: PMC9505958 DOI: 10.3390/microorganisms10091772] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/24/2022] [Accepted: 08/30/2022] [Indexed: 11/18/2022] Open
Abstract
Yeast has been used as a model for several diseases as it is the simplest unicellular eukaryote, safe and easy to culture and harbors most of the fundamental processes that are present in almost all higher eukaryotes, including humans. From understanding the pathogenesis of disease to drug discovery studies, yeast has served as an important biosensor. It is not only due to the conservation of genetics, amenable modification of its genome and easily accessible analytical methods, but also some characteristic features such as its ability to survive with defective mitochondria, making it a highly flexible microbe for designing whole-cell biosensing systems. The aim of this review is to report on how yeasts have been utilized as biosensors, reporting on responses to various stimuli.
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Qiao J, Cui H, Wang M, Fu X, Wang X, Li X, Huang H. Integrated biorefinery approaches for the industrialization of cellulosic ethanol fuel. BIORESOURCE TECHNOLOGY 2022; 360:127516. [PMID: 35764282 DOI: 10.1016/j.biortech.2022.127516] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/20/2022] [Accepted: 06/22/2022] [Indexed: 06/15/2023]
Abstract
Lignocellulosic biomass is an abundant and sustainable raw material, but its conversion into ethanol fuel has not yet achieved large-scale industrialization and economic benefits. Integrated biorefineries have been widely identified as the key to achieving this goal. Here, four promising routes were summarized to assemble the new industrial plants for cellulose-based fuels and chemicals, including 1) integration of cellulase production systems into current cellulosic ethanol processes; 2) combination of processes and facilities between cellulosic ethanol and first-generation ethanol; 3) application of enzyme-free saccharification processes and computational approaches to increase the bioethanol yield and optimize the integration process; 4) production of multiple products to maximize the value derived from the lignocellulosic biomass. Finally, the remaining challenges and perspectives of this field are also discussed.
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Affiliation(s)
- Jie Qiao
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 2 Xuelin Road, Nanjing 210097, China
| | - Haiyang Cui
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
| | - Minghui Wang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 2 Xuelin Road, Nanjing 210097, China
| | - Xianshen Fu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 2 Xuelin Road, Nanjing 210097, China
| | - Xinyue Wang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 2 Xuelin Road, Nanjing 210097, China
| | - Xiujuan Li
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 2 Xuelin Road, Nanjing 210097, China.
| | - He Huang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 2 Xuelin Road, Nanjing 210097, China; School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, China
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6
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Rafieenia R, Atkinson E, Ledesma-Amaro R. Division of labor for substrate utilization in natural and synthetic microbial communities. Curr Opin Biotechnol 2022; 75:102706. [DOI: 10.1016/j.copbio.2022.102706] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/07/2022] [Accepted: 02/15/2022] [Indexed: 01/30/2023]
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Šuchová K, Fehér C, Ravn JL, Bedő S, Biely P, Geijer C. Cellulose- and xylan-degrading yeasts: Enzymes, applications and biotechnological potential. Biotechnol Adv 2022; 59:107981. [DOI: 10.1016/j.biotechadv.2022.107981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 05/08/2022] [Accepted: 05/10/2022] [Indexed: 01/23/2023]
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Abstract
In this study, we overcame the limitations of single-enzyme system catalysis by codisplaying Candida rugosa lipase 1 (CRL1) and Rhizopus oryzae lipase (ROL) on the cell surfaces of the whole-cell catalyst Pichia pastoris to produce biodiesel from tallow seed oil. We screened double antibiotic-resistant strains on tributyrin plates, performed second electroporation based on single-displayed ROL on GS115/KpRS recombinants and single-displayed CRL1 on GS115/ZCS recombinants and obtained an ROL/CRL1 codisplay on P. pastoris GS115 surfaces. The maximum activity of the codisplaying GS115/pRCS recombinant was 470.59 U/g dried cells, which was 3.9-fold and 1.3-fold higher than that of single-displayed ROL and CRL1, respectively. When self-immobilized lipases were used as whole-cell catalysts, the rate of methyl ester production from GS115/pRCS harboring ROL and CRL1 was 1.4-fold higher than that obtained with single-displayed ROL. Therefore, biodiesel catalysis by synergetic codisplayed enzymes is an alternative biodiesel production strategy.
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Andreu C, Gómez-Peinado J, Winandy L, Fischer R, Del Olmo ML. Surface display of HFBI and DewA hydrophobins on Saccharomyces cerevisiae modifies tolerance to several adverse conditions and biocatalytic performance. Appl Microbiol Biotechnol 2021; 105:1505-1518. [PMID: 33484321 DOI: 10.1007/s00253-021-11090-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/14/2020] [Accepted: 01/03/2021] [Indexed: 02/06/2023]
Abstract
Hydrophobins are relatively small proteins produced naturally by filamentous fungi with interesting biotechnological and biomedical applications given their self-assembly capacity, efficient adherence to natural and artificial surfaces, and to introduce modifications on the hydrophobicity/hydrophilicity of surfaces. In this work we demonstrate the efficient expression on the S. cerevisiae cell surface of class II HFBI of Trichoderma reesei and class I DewA of Aspergillus nidulans, a hydrophobin not previously exposed, using the Yeast Surface Display a-agglutinin (Aga1-Aga2) system. We show that the resulting modifications affect surface properties, and also yeast cells' resistance to several adverse conditions. The fact that viability of the engineered strains increases under heat and osmotic stress is particularly interesting. Besides, improved biocatalytic activity toward the reduction of ketone 1-phenoxypropan-2-one takes place in the reactions carried out at both 30 °C and 40 °C, within a concentration range between 0.65 and 2.5 mg/mL. These results suggest interesting potential applications for hydrophobin-exposing yeasts. KEY POINTS : • Class I hydrophobin DewA can be efficiently exposed on S. cerevisiae cell surfaces. • Yeast exposure of HFBI and DewA increases osmotic and heat resistance. • Engineered strains show modified biocatalytic behavior.
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Affiliation(s)
- Cecilia Andreu
- Departament de Química Orgànica, Facultat de Farmàcia, Universitat de València, Burjassot, València, Spain
| | - Javier Gómez-Peinado
- Departament de Bioquímica i Biologia Molecular, Facultat de Ciències Biològiques, Universitat de València, Burjassot, València, Spain
| | - Lex Winandy
- Department of Microbiology, Karlsruhe Institute of Technology (KIT)-South Campus, Fritz-Haber-Weg 4, D-76131, Karlsruhe, Germany
| | - Reinhard Fischer
- Department of Microbiology, Karlsruhe Institute of Technology (KIT)-South Campus, Fritz-Haber-Weg 4, D-76131, Karlsruhe, Germany
| | - Marcel Li Del Olmo
- Departament de Bioquímica i Biologia Molecular, Facultat de Ciències Biològiques, Universitat de València, Burjassot, València, Spain.
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10
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Ye M, Ye Y, Du Z, Chen G. Cell-surface engineering of yeasts for whole-cell biocatalysts. Bioprocess Biosyst Eng 2021; 44:1003-1019. [PMID: 33389168 DOI: 10.1007/s00449-020-02484-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 11/16/2020] [Indexed: 01/23/2023]
Abstract
Due to the unique advantages comparing with traditional free enzymes and chemical catalysis, whole-cell biocatalysts have been widely used to catalyze reactions effectively, simply and environment friendly. Cell-surface display technology provides a novel and effective approach for improved whole-cell biocatalysts expressing heterologous enzymes on the cell surface. They can overcome the substrate transport limitation of the intracellular expression and provide the enzymes with enhanced properties. Among all the host surface-displaying microorganisms, yeast is ideally suitable for constructing whole cell-surface-displaying biocatalyst, because of the large cell size, the generally regarded as safe (GRAS) status, and the perfect post-translational processing of secreted proteins. Yeast cell-surface display system has been a promising and powerful method for development of novel and improved engineered biocatalysts. In this review, the characterization and principles of yeast cell-surface display and the applications of yeast cell-surface display in engineered whole-cell biocatalysts as well as the improvement of the enzyme efficiency are summarized and discussed.
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Affiliation(s)
- Mengqi Ye
- Marine College, Shandong University, Weihai, 264209, China
| | - Yuqi Ye
- Marine College, Shandong University, Weihai, 264209, China
| | - Zongjun Du
- Marine College, Shandong University, Weihai, 264209, China
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China
| | - Guanjun Chen
- Marine College, Shandong University, Weihai, 264209, China.
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China.
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11
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Cripwell RA, Favaro L, Viljoen-Bloom M, van Zyl WH. Consolidated bioprocessing of raw starch to ethanol by Saccharomyces cerevisiae: Achievements and challenges. Biotechnol Adv 2020; 42:107579. [PMID: 32593775 DOI: 10.1016/j.biotechadv.2020.107579] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 06/05/2020] [Accepted: 06/14/2020] [Indexed: 12/30/2022]
Abstract
Recent advances in amylolytic strain engineering for starch-to-ethanol conversion have provided a platform for the development of raw starch consolidated bioprocessing (CBP) technologies. Several proof-of-concept studies identified improved enzyme combinations, alternative feedstocks and novel host strains for evaluation and application under fermentation conditions. However, further research efforts are required before this technology can be scaled up to an industrial level. In this review, different CBP approaches are defined and discussed, also highlighting the role of auxiliary enzymes for a supplemented CBP process. Various achievements in the development of amylolytic Saccharomyces cerevisiae strains for CBP of raw starch and the remaining challenges that need to be tackled/pursued to bring yeast raw starch CBP to industrial realization, are described. Looking towards the future, it provides potential solutions to develop more cost-effective processes that include cheaper substrates, integration of the 1G and 2G economies and implementing a biorefinery concept where high-value products are also derived from starchy substrates.
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Affiliation(s)
- Rosemary A Cripwell
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Lorenzo Favaro
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università di Padova, Agripolis, Viale dell'Università 16, 35020, Legnaro, Padova, Italy
| | - Marinda Viljoen-Bloom
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Willem H van Zyl
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa.
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12
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Consolidated bio-saccharification: Leading lignocellulose bioconversion into the real world. Biotechnol Adv 2020; 40:107535. [DOI: 10.1016/j.biotechadv.2020.107535] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/03/2020] [Accepted: 02/12/2020] [Indexed: 11/22/2022]
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13
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Ellis GA, Klein WP, Lasarte-Aragonés G, Thakur M, Walper SA, Medintz IL. Artificial Multienzyme Scaffolds: Pursuing in Vitro Substrate Channeling with an Overview of Current Progress. ACS Catal 2019. [DOI: 10.1021/acscatal.9b02413] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Gregory A. Ellis
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
| | - William P. Klein
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
- National Research Council, Washington, D.C. 20001, United States
| | - Guillermo Lasarte-Aragonés
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
- College of Science, George Mason University, Fairfax, Virginia 22030, United States
| | - Meghna Thakur
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
- College of Science, George Mason University, Fairfax, Virginia 22030, United States
| | - Scott A. Walper
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Igor L. Medintz
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
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14
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Liu S, Liu YJ, Feng Y, Li B, Cui Q. Construction of consolidated bio-saccharification biocatalyst and process optimization for highly efficient lignocellulose solubilization. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:35. [PMID: 30820245 PMCID: PMC6378752 DOI: 10.1186/s13068-019-1374-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 02/07/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND The industrial conversion of biomass to high-value biofuels and biochemical is mainly restricted by lignocellulose solubilization. Consolidated bio-saccharification (CBS) is considered a promising process for lignocellulose solubilization depending on whole-cell biocatalysts that simultaneously perform effective cellulase production and hydrolysis. However, it usually takes a long time to reach a high saccharification level using the current CBS biocatalyst and process. RESULTS To promote the saccharification efficiency and reduce the cost, a Clostridium thermocellum recombinant strain ∆pyrF::KBm was constructed as a new CBS biocatalyst in this study. The key CBS factors, including the medium, inoculum size and cultivation, and substrate load, were investigated and optimized. The saccharification process was also stimulated by adding free hemicellulases, suggesting the need to further enhance hemicellulase activity of the whole-cell catalyst. Under the optimal conditions, the CBS process was shortened by 50% with pretreated wheat straw as the substrate. The sugar yield reached 0.795 g/g and the saccharification level was 89.3%. CONCLUSIONS This work provided a new biocatalyst and an optimized process of CBS and confirmed that CBS is a feasible strategy for cost-efficient solubilization of lignocellulose, which will greatly promote the industrial utilization of lignocellulosic biomass.
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Affiliation(s)
- Shiyue Liu
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian, China
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
| | - Ya-Jun Liu
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian, China
| | - Yingang Feng
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian, China
| | - Bin Li
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian, China
| | - Qiu Cui
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian, China
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Abstract
An application-related definition for immobilized enzymes was given by Chibata in 1978 […]
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16
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Tabañag IDF, Chu IM, Wei YH, Tsai SL. Ethanol production from hemicellulose by a consortium of different genetically-modified sacharomyces cerevisiae. J Taiwan Inst Chem Eng 2018. [DOI: 10.1016/j.jtice.2018.04.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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