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Mazzoli R, Pescarolo S, Gilli G, Gilardi G, Valetti F. Hydrogen production pathways in Clostridia and their improvement by metabolic engineering. Biotechnol Adv 2024; 73:108379. [PMID: 38754796 DOI: 10.1016/j.biotechadv.2024.108379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 05/13/2024] [Accepted: 05/13/2024] [Indexed: 05/18/2024]
Abstract
Biological production of hydrogen has a tremendous potential as an environmentally sustainable technology to generate a clean fuel. Among the different available methods to produce biohydrogen, dark fermentation features the highest productivity and can be used as a means to dispose of organic waste biomass. Within this approach, Clostridia have the highest theoretical H2 production yield. Nonetheless, most strains show actual yields far lower than the theoretical maximum: improving their efficiency becomes necessary for achieving cost-effective fermentation processes. This review aims at providing a survey of the metabolic network involved in H2 generation in Clostridia and strategies used to improve it through metabolic engineering. Together with current achievements, a number of future perspectives to implement these results will be illustrated.
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Affiliation(s)
- Roberto Mazzoli
- Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes, Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, 10123 Torino, Italy.
| | - Simone Pescarolo
- Biology applied to the environment, Laboratories of microbiology and ecotoxicology, Ecobioqual, Environment Park. Via Livorno 60, 10144 Torino, Italy
| | - Giorgio Gilli
- Department of Sciences of Public Health and Pediatrics, School of Medicine, University of Torino, Via Santena 5 bis, 10126 Torino, Italy
| | - Gianfranco Gilardi
- Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes, Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, 10123 Torino, Italy
| | - Francesca Valetti
- Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes, Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, 10123 Torino, Italy.
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2
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Zhang K, Qin M, Hou Y, Zhang W, Wang Z, Wang H. Efficient production of guanosine in Escherichia coli by combinatorial metabolic engineering. Microb Cell Fact 2024; 23:182. [PMID: 38898430 PMCID: PMC11186194 DOI: 10.1186/s12934-024-02452-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Accepted: 06/06/2024] [Indexed: 06/21/2024] Open
Abstract
BACKGROUND Guanosine is a purine nucleoside that is widely used as a raw material for food additives and pharmaceutical products. Microbial fermentation is the main production method of guanosine. However, the guanosine-producing strains possess multiple metabolic pathway interactions and complex regulatory mechanisms. The lack of strains with efficiently producing-guanosine greatly limited industrial application. RESULTS We attempted to efficiently produce guanosine in Escherichia coli using systematic metabolic engineering. First, we overexpressed the purine synthesis pathway from Bacillus subtilis and the prs gene, and deleted three genes involved in guanosine catabolism to increase guanosine accumulation. Subsequently, we attenuated purA expression and eliminated feedback and transcription dual inhibition. Then, we modified the metabolic flux of the glycolysis and Entner-Doudoroff (ED) pathways and performed redox cofactors rebalancing. Finally, transporter engineering and enhancing the guanosine synthesis pathway further increased the guanosine titre to 134.9 mg/L. After 72 h of the fed-batch fermentation in shake-flask, the guanosine titre achieved 289.8 mg/L. CONCLUSIONS Our results reveal that the guanosine synthesis pathway was successfully optimized by combinatorial metabolic engineering, which could be applicable to the efficient synthesis of other nucleoside products.
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Affiliation(s)
- Kun Zhang
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, 453007, China
| | - Mengxing Qin
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, 453007, China
| | - Yu Hou
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, 453007, China
| | - Wenwen Zhang
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, 453007, China
| | - Zhenyu Wang
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, 453007, China
| | - Hailei Wang
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, 453007, China.
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Kim SH, Hwang JH, Kim HJ, Oh SJ, Kim HJ, Shin N, Kim SH, Park JH, Bhatia SK, Yang YH. Enhancement of biohydrogen production in Clostridium acetobutylicum ATCC 824 by overexpression of glyceraldehyde-3-phosphate dehydrogenase gene. Enzyme Microb Technol 2023; 168:110244. [PMID: 37196383 DOI: 10.1016/j.enzmictec.2023.110244] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/28/2023] [Accepted: 05/01/2023] [Indexed: 05/19/2023]
Abstract
In the dark fermentation of hydrogen, development of production host is crucial as bacteria act on substrates and produce hydrogen. The present study aimed to improve hydrogen production through the development of Clostridium acetobutylicum as a superior biohydrogen producer. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which produces NADH/NADPH for metabolites and energy in primary pathways, was introduced to enhance hydrogen production. The strain CAC824-G containing gapC that encodes GAPDH showed a 66.3 % higher hydrogen production than the wild-type strain, with increased NADH and NADPH pools. Glucose consumption and other byproducts, such as acetone, butanol, and ethanol, were also high in CAC824-G. Overexpression of gapC resulted in increased hydrogen production with sugars obtained from different biomass, even in the presence of inhibitors such as vanillin, 5-hydroxymethylfufural, acetic acid, and formic acid. Our results imply that overexpression of gapC in Clostridium is possible to expand the production of the reported biochemicals to produce hydrogen.
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Affiliation(s)
- Sang Hyun Kim
- Department of Biological Engineering, College of Engineering, Konkuk University, 120, Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Jeong Hyeon Hwang
- Department of Biological Engineering, College of Engineering, Konkuk University, 120, Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Hyun Joong Kim
- Department of Biological Engineering, College of Engineering, Konkuk University, 120, Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Suk Jin Oh
- Department of Biological Engineering, College of Engineering, Konkuk University, 120, Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Hyun Jin Kim
- Department of Biological Engineering, College of Engineering, Konkuk University, 120, Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Nara Shin
- Department of Biological Engineering, College of Engineering, Konkuk University, 120, Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Sang-Hyoun Kim
- School of Civil and Environmental Engineering, Yonsei University, 50, Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Jeong-Hoon Park
- Sustainable Technology and Wellness R&D Group, Korea Institute of Industrial Technology (KITECH), Jeju-si 63243, Republic of Korea
| | - Shashi Kant Bhatia
- Department of Biological Engineering, College of Engineering, Konkuk University, 120, Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea; Institute for Ubiquitous Information Technology and Application, Konkuk University, Seoul 05029, Republic of Korea.
| | - Yung-Hun Yang
- Department of Biological Engineering, College of Engineering, Konkuk University, 120, Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea; Institute for Ubiquitous Information Technology and Application, Konkuk University, Seoul 05029, Republic of Korea.
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4
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Sun X, Peng Z, Li C, Zheng Y, Cheng Y, Zong J, Lu F, Li Y, Li Q. Combinatorial metabolic engineering and tolerance evolving of Escherichia coli for high production of 2'-fucosyllactose. BIORESOURCE TECHNOLOGY 2023; 372:128667. [PMID: 36702325 DOI: 10.1016/j.biortech.2023.128667] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 01/19/2023] [Accepted: 01/20/2023] [Indexed: 06/18/2023]
Abstract
2'-Fucosyllactose (2'-FL) is an important functional ingredient of advanced infant formula. Here, Escherichia coli MG1655 was engineered for achieving high 2'-FL production. The expressions of 2'-FL synthesis pathway genes were finely regulated with single or multi copies according to rate-limiting enzyme diagnosis. On this basic, the branch pathway genes were deleted, and the overexpression of the 2'-FL efflux protein SetA and the fructose-1,6-bisphosphatase GlpX were tuned. The resulting strain produced 46.06 ± 1.28 g/L 2'-FL in a 5-L fermenter. Furtherly, adaptive laboratory evolution was conducted. A rpoC gene mutation was obtained which could improve the cell tolerance and the 2'-FL production up to 61.06 ± 1.93 g/L, with the highest productivity of 1.70 g/L/h among E. coli strains by now. Taken together, this work provides a combinatorial strategy to improve 2'-FL accumulation including rational fine-tuning pathway genes expressions and irrational adaptive laboratory evolution. This study should be helpful for constructing high level 2'-FL producers.
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Affiliation(s)
- Xue Sun
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, National Engineering Laboratory for Industrial Enzymes, Tianjin 300457, PR China
| | - Zetao Peng
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, National Engineering Laboratory for Industrial Enzymes, Tianjin 300457, PR China
| | - Chang Li
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, National Engineering Laboratory for Industrial Enzymes, Tianjin 300457, PR China
| | - Yanling Zheng
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, National Engineering Laboratory for Industrial Enzymes, Tianjin 300457, PR China
| | - Ya'nan Cheng
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, National Engineering Laboratory for Industrial Enzymes, Tianjin 300457, PR China
| | - Jianfei Zong
- Shandong SynBio-Vision Technology Co., Ltd, Weifang 262500, PR China
| | - Fuping Lu
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, National Engineering Laboratory for Industrial Enzymes, Tianjin 300457, PR China
| | - Yu Li
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, National Engineering Laboratory for Industrial Enzymes, Tianjin 300457, PR China
| | - Qinggang Li
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, National Engineering Laboratory for Industrial Enzymes, Tianjin 300457, PR China; Haihe Laboratory of Synthetic Biology, Tianjin 300308, PR China.
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5
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Hao Y, Pan X, Xing R, You J, Hu M, Liu Z, Li X, Xu M, Rao Z. High-level production of L-valine in Escherichia coli using multi-modular engineering. BIORESOURCE TECHNOLOGY 2022; 359:127461. [PMID: 35700900 DOI: 10.1016/j.biortech.2022.127461] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 06/08/2022] [Accepted: 06/09/2022] [Indexed: 06/15/2023]
Abstract
L-valine is a valuable amino acid in mammals that is used as the main component of feed additives. The low efficiency of the fermentation titer limits the industrial application of L-valine. Here, an L-valine-producing strain of Escherichia coli was obtained using a multi-modular strategy. Initially, a chassis strain was generated by mutagenesis and high-throughput screening. The L-valine biosynthetic pathway and transport module were modified to improve the L-valine titer. Subsequently, the transcription factors associated with L-valine biosynthesis were investigated. Overexpression of PdhR and inhibition of the expression of RpoS promoted L-valine synthesis. Finally, the NADPH supply was enhanced after the introduction of the heterologous Entner-Doudoroff (ED) pathway from Zymomonas mobilis. The strain VAL38 produced 92 g/L L-valine in a 5-L bioreactor with a yield of 0.34 g/g glucose. This strategy is provided as a reference for improving the production performance of cell factories for L-valine and its derivatives.
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Affiliation(s)
- Yanan Hao
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xuewei Pan
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Rufan Xing
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jiajia You
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Mengkai Hu
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Zhifei Liu
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xiangfei Li
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Meijuan Xu
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Zhiming Rao
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
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6
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Cao Y, Liu H, Liu W, Guo J, Xian M. Debottlenecking the biological hydrogen production pathway of dark fermentation: insight into the impact of strain improvement. Microb Cell Fact 2022; 21:166. [PMID: 35986320 PMCID: PMC9389701 DOI: 10.1186/s12934-022-01893-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 07/26/2022] [Indexed: 11/26/2022] Open
Abstract
Confronted with the exhaustion of the earth’s fossil fuel reservoirs, bio-based process to produce renewable energy is receiving significant interest. Hydrogen is considered as an attractive energy carrier that can replace fossil fuels in the future mainly due to its high energy content, recyclability and environment-friendly nature. Biological hydrogen production from renewable biomass or waste materials by dark fermentation is a promising alternative to conventional routes since it is energy-saving and reduces environmental pollution. However, the current yield and evolution rate of fermentative hydrogen production are still low. Strain improvement of the microorganisms employed for hydrogen production is required to make the process competitive with traditional production methods. The present review summarizes recent progresses on the screening for highly efficient hydrogen-producing strains using various strategies. As the metabolic pathways for fermentative hydrogen production have been largely resolved, it is now possible to engineer the hydrogen-producing strains by rational design. The hydrogen yields and production rates by different genetically modified microorganisms are discussed. The key limitations and challenges faced in present studies are also proposed. We hope that this review can provide useful information for scientists in the field of fermentative hydrogen production. Hydrogen can be generated by microorganisms. Dark fermentation is efficient for biological hydrogen production. Strain improvement is critical to enhancing hydrogen-producing ability.
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7
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Tafur Rangel AE, Ríos W, Mejía D, Ojeda C, Carlson R, Gómez Ramírez JM, González Barrios AF. In silico Design for Systems-Based Metabolic Engineering for the Bioconversion of Valuable Compounds From Industrial By-Products. Front Genet 2021; 12:633073. [PMID: 33868371 PMCID: PMC8044919 DOI: 10.3389/fgene.2021.633073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 02/23/2021] [Indexed: 11/13/2022] Open
Abstract
Selecting appropriate metabolic engineering targets to build efficient cell factories maximizing the bioconversion of industrial by-products to valuable compounds taking into account time restrictions is a significant challenge in industrial biotechnology. Microbial metabolism engineering following a rational design has been widely studied. However, it is a cost-, time-, and laborious-intensive process because of the cell network complexity; thus, it is important to use tools that allow predicting gene deletions. An in silico experiment was performed to model and understand the metabolic engineering effects on the cell factory considering a second complexity level by transcriptomics data integration. In this study, a systems-based metabolic engineering target prediction was used to increase glycerol bioconversion to succinic acid based on Escherichia coli. Transcriptomics analysis suggests insights on how to increase cell glycerol utilization to further design efficient cell factories. Three E. coli models were used: a core model, a second model based on the integration of transcriptomics data obtained from growth in an optimized culture media, and a third one obtained after integration of transcriptomics data from adaptive laboratory evolution (ALE) experiments. A total of 2,402 strains were obtained with fumarase and pyruvate dehydrogenase being frequently predicted for all the models, suggesting these reactions as essential to increase succinic acid production. Finally, based on using flux balance analysis (FBA) results for all the mutants predicted, a machine learning method was developed to predict new mutants as well as to propose optimal metabolic engineering targets and mutants based on the measurement of the importance of each knockout's (feature's) contribution. Glycerol has become an interesting carbon source for industrial processes due to biodiesel business growth since it has shown promising results in terms of biomass/substrate yields. The combination of transcriptome, systems metabolic modeling, and machine learning analyses revealed the versatility of computational models to predict key metabolic engineering targets in a less cost-, time-, and laborious-intensive process. These data provide a platform to improve the prediction of metabolic engineering targets to design efficient cell factories. Our results may also work as a guide and platform for the selection/engineering of microorganisms for the production of interesting chemical compounds.
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Affiliation(s)
- Albert Enrique Tafur Rangel
- Grupo de Diseño de Productos y Procesos, Department of Chemical and Food Engineering, Universidad de los Andes, Bogotá, Colombia
- Grupo de Investigación CINBIOS, Department of Microbiology, Universidad Popular del Cesar, Valledupar, Colombia
| | - Wendy Ríos
- Grupo de Diseño de Productos y Procesos, Department of Chemical and Food Engineering, Universidad de los Andes, Bogotá, Colombia
| | - Daisy Mejía
- Grupo de Diseño de Productos y Procesos, Department of Chemical and Food Engineering, Universidad de los Andes, Bogotá, Colombia
| | - Carmen Ojeda
- Grupo de Diseño de Productos y Procesos, Department of Chemical and Food Engineering, Universidad de los Andes, Bogotá, Colombia
| | - Ross Carlson
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, United States
| | - Jorge Mario Gómez Ramírez
- Grupo de Diseño de Productos y Procesos, Department of Chemical and Food Engineering, Universidad de los Andes, Bogotá, Colombia
| | - Andrés Fernando González Barrios
- Grupo de Diseño de Productos y Procesos, Department of Chemical and Food Engineering, Universidad de los Andes, Bogotá, Colombia
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8
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Fan Q, Neubauer P, Lenz O, Gimpel M. Heterologous Hydrogenase Overproduction Systems for Biotechnology-An Overview. Int J Mol Sci 2020; 21:E5890. [PMID: 32824336 PMCID: PMC7460606 DOI: 10.3390/ijms21165890] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/06/2020] [Accepted: 08/14/2020] [Indexed: 01/16/2023] Open
Abstract
Hydrogenases are complex metalloenzymes, showing tremendous potential as H2-converting redox catalysts for application in light-driven H2 production, enzymatic fuel cells and H2-driven cofactor regeneration. They catalyze the reversible oxidation of hydrogen into protons and electrons. The apo-enzymes are not active unless they are modified by a complicated post-translational maturation process that is responsible for the assembly and incorporation of the complex metal center. The catalytic center is usually easily inactivated by oxidation, and the separation and purification of the active protein is challenging. The understanding of the catalytic mechanisms progresses slowly, since the purification of the enzymes from their native hosts is often difficult, and in some case impossible. Over the past decades, only a limited number of studies report the homologous or heterologous production of high yields of hydrogenase. In this review, we emphasize recent discoveries that have greatly improved our understanding of microbial hydrogenases. We compare various heterologous hydrogenase production systems as well as in vitro hydrogenase maturation systems and discuss their perspectives for enhanced biohydrogen production. Additionally, activities of hydrogenases isolated from either recombinant organisms or in vivo/in vitro maturation approaches were systematically compared, and future perspectives for this research area are discussed.
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Affiliation(s)
- Qin Fan
- Institute of Biotechnology, Technical University of Berlin, Ackerstraße 76, 13355 Berlin, Germany; (Q.F.); (P.N.)
| | - Peter Neubauer
- Institute of Biotechnology, Technical University of Berlin, Ackerstraße 76, 13355 Berlin, Germany; (Q.F.); (P.N.)
| | - Oliver Lenz
- Department of Chemistry, Technical University of Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany;
| | - Matthias Gimpel
- Institute of Biotechnology, Technical University of Berlin, Ackerstraße 76, 13355 Berlin, Germany; (Q.F.); (P.N.)
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9
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Valle A, Cantero D, Bolívar J. Metabolic engineering for the optimization of hydrogen production in Escherichia coli: A review. Biotechnol Adv 2019; 37:616-633. [DOI: 10.1016/j.biotechadv.2019.03.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 03/05/2019] [Accepted: 03/07/2019] [Indexed: 12/29/2022]
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10
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Biological hydrogen production: molecular and electrolytic perspectives. World J Microbiol Biotechnol 2019; 35:116. [PMID: 31332538 DOI: 10.1007/s11274-019-2692-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 07/07/2019] [Indexed: 10/26/2022]
Abstract
Exploration of renewable energy sources is an imperative task in order to replace fossil fuels and to diminish atmospheric pollution. Hydrogen is considered one of the most promising fuels for the future and implores further investigation to find eco-friendly ways toward viable production. Expansive processes like electrolysis and fossil fuels are currently being used to produce hydrogen. Biological hydrogen production (BHP) displays recyclable and economical traits, and is thus imperative for hydrogen economy. Three basic modes of BHP were investigated, including bio photolysis, photo fermentation and dark fermentation. Photosynthetic microorganisms could readily serve as powerhouses to successively produce this type of energy. Cyanobacteria, blue green algae (bio photolysis) and some purple non-sulfur bacteria (Photo fermentation) utilize solar energy and produce hydrogen during their metabolic processes. Ionic species, including hydrogen (H+) and electrons (e-) are combined into hydrogen gas (H2), with the use of special enzymes called hydrogenases in the case of bio photolysis, and nitrogenases catalyze the formation of hydrogen in the case of photo fermentation. Nevertheless, oxygen sensitivity of these enzymes is a drawback for bio photolysis and photo fermentation, whereas, the amount of hydrogen per unit substrate produced appears insufficient for dark fermentation. This review focuses on innovative advances in the bioprocess research, genetic engineering and bioprocess technologies such as microbial fuel cell technology, in developing bio hydrogen production.
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11
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Felipe Hernández-Pérez A, de Arruda PV, Sene L, da Silva SS, Kumar Chandel A, de Almeida Felipe MDG. Xylitol bioproduction: state-of-the-art, industrial paradigm shift, and opportunities for integrated biorefineries. Crit Rev Biotechnol 2019; 39:924-943. [DOI: 10.1080/07388551.2019.1640658] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
| | - Priscila Vaz de Arruda
- Department of Bioprocess Engineering and Biotechnology-COEBB/TD, Universidade Tecnológica Federal do Paraná, Toledo, Brazil
| | - Luciane Sene
- Center for Exact and Technological Sciences, Universidade Estadual do Oeste de Paraná (UNIOESTE), Cascavel, Brazil
| | - Silvio Silvério da Silva
- Departamento de Biotecnologia, Escola de Engenharia de Lorena (EEL), Universidade de São Paulo, Lorena, Brazil
| | - Anuj Kumar Chandel
- Departamento de Biotecnologia, Escola de Engenharia de Lorena (EEL), Universidade de São Paulo, Lorena, Brazil
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12
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Sha Y, Sun T, Qiu Y, Zhu Y, Zhan Y, Zhang Y, Xu Z, Li S, Feng X, Xu H. Investigation of Glutamate Dependence Mechanism for Poly-γ-glutamic Acid Production in Bacillus subtilis on the Basis of Transcriptome Analysis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:6263-6274. [PMID: 31088055 DOI: 10.1021/acs.jafc.9b01755] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The development of commercial poly-γ-glutamic acid (γ-PGA) production by glutamate-dependent strains requires understanding the glutamate dependence mechanism in the strains. Here, we first systematically analyzed the response pattern of Bacillus subtilis to glutamate addition by comparative transcriptomics. Glutamate addition induced great changes in intracellular metabolite concentrations and significantly upregulated genes involved in the central metabolic pathways. Subsequent gene overexpression experiments revealed that only the enhancement of glutamate synthesis pathway successfully led to γ-PGA accumulation without glutamate addition, indicating the key role of intracellular glutamate for γ-PGA synthesis in glutamate-dependent strains. Finally, by a combination of metabolic engineering targets, the γ-PGA titer reached 10.21 ± 0.42 g/L without glutamate addition. Exogenous glutamate further enhanced the γ-PGA yield (35.52 ± 0.26 g/L) and productivity (0.74 g/(L h)) in shake-flask fermentation. This work provides insights into the glutamate dependence mechanism in B. subtilis and reveals potential molecular targets for increasing economical γ-PGA production.
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Affiliation(s)
- Yuanyuan Sha
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , People's Republic of China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , People's Republic of China
| | - Tao Sun
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , People's Republic of China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , People's Republic of China
| | - Yibin Qiu
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , People's Republic of China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , People's Republic of China
| | - Yifan Zhu
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , People's Republic of China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , People's Republic of China
| | - Yijing Zhan
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , People's Republic of China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , People's Republic of China
- Nanjing Shineking Biotech Co., Ltd. , Nanjing 210061 , People's Republic of China
| | - Yatao Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , People's Republic of China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , People's Republic of China
| | - Zongqi Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , People's Republic of China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , People's Republic of China
| | - Sha Li
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , People's Republic of China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , People's Republic of China
| | - Xiaohai Feng
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , People's Republic of China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , People's Republic of China
| | - Hong Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , People's Republic of China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , People's Republic of China
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13
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Lyu Y, Wu J, Shi Y. Metabolic and physiological perturbations of Escherichia coli W3100 by bacterial small RNA RyhB. Biochimie 2019; 162:144-155. [PMID: 31002843 DOI: 10.1016/j.biochi.2019.04.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Accepted: 04/12/2019] [Indexed: 11/17/2022]
Abstract
RyhB is a key regulator of iron level in Escherichia coli (E. coli), which assists in conserving iron for life-sustaining cellular functions when cytoplasmic levels of the ferrous form of iron is limited. RyhB affects glucose metabolism. Seventy percent of the genes that are regulated by RyhB are related to metabolism. We demonstrated for the first time that the activity of the pentose phosphate pathway increased upon ryhB activation using a13C stable isotope-based technique called METAFoR (Metabolic flux ratio analysis). U-13C glucose-based studies showed that the reversible exchange activity of serine and glycine was enhanced by flux redistribution, which further favors NADPH formation. In addition, Entner-Doudoroff (ED) pathway activity was inhibited in the ryhB-defective cells. Quantitative physiology-based experiments highlighted a significant increase in the levels of reactive oxygen species (ROS) in ryhB-induced W3100 E. coli cells in batch culture. A simultaneous decrease in NADH/NAD+ and NADPH/NADP+ ratios outlined the potentially direct roles of NADH and NADPH in antagonizing the excess ROS formed after ryhB activation. Our observations offer a new perspective regarding the roles of RyhB and highlight that this small RNA can significantly affect cell metabolism in addition to its role as a regulator of gene expression.
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Affiliation(s)
- Yu Lyu
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, 230027, People's Republic of China
| | - Jihui Wu
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, 230027, People's Republic of China.
| | - Yunyu Shi
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, 230027, People's Republic of China.
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14
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Zhan Y, Sheng B, Wang H, Shi J, Cai D, Yi L, Yang S, Wen Z, Ma X, Chen S. Rewiring glycerol metabolism for enhanced production of poly-γ-glutamic acid in Bacillus licheniformis. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:306. [PMID: 30455735 PMCID: PMC6225680 DOI: 10.1186/s13068-018-1311-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 11/01/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Poly-γ-glutamic acid (γ-PGA) is a natural polymer with great potential applications in areas of agriculture, industry, and pharmaceutical. The biodiesel-derived glycerol can be used as an attractive feedstock for γ-PGA production due to its availability and low price; however, insufficient production of γ-PGA from glycerol is limitation. RESULTS The metabolic pathway of Bacillus licheniformis WX-02 was rewired to improve the efficiency of glycerol assimilation and the supply of NADPH for γ-PGA synthesis. GlpK, GlpX, Zwf, and Tkt1 were found to be the key enzymes for γ-PGA synthesis using glycerol as a feedstock. Through combinational expression of these key enzymes, the γ-PGA titer increased to 19.20 ± 1.57 g/L, which was 1.50-fold of that of the wild-type strain. Then, we studied the flux distributions, gene expression, and intracellular metabolites in WX-02 and the recombinant strain BC4 (over-expression of the above quadruple enzymes). Our results indicated that over-expression of the quadruple enzymes redistributed metabolic flux to γ-PGA synthesis. Furthermore, using crude glycerol as carbon source, the BC4 strain showed a high productivity of 0.38 g/L/h, and produced 18.41 g/L γ-PGA, with a high yield of 0.46 g γ-PGA/g glycerol. CONCLUSIONS The approach to rewiring of metabolic pathways enables B. licheniformis to efficiently synthesize γ-PGA from glycerol. The γ-PGA productivity reported in this work is the highest obtained in glutamate-free medium. The present study demonstrates that the recombinant B. licheniformis strain shows significant potential to produce valuable compounds from crude glycerol.
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Affiliation(s)
- Yangyang Zhan
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, 430062 Hubei People’s Republic of China
| | - Bojie Sheng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Huan Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, 430062 Hubei People’s Republic of China
| | - Jiao Shi
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, 430062 Hubei People’s Republic of China
| | - Dongbo Cai
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, 430062 Hubei People’s Republic of China
| | - Li Yi
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, 430062 Hubei People’s Republic of China
| | - Shihui Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, 430062 Hubei People’s Republic of China
| | - Zhiyou Wen
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
- Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011 USA
| | - Xin Ma
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, 430062 Hubei People’s Republic of China
| | - Shouwen Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, 430062 Hubei People’s Republic of China
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
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15
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Metabolomics of colistin methanesulfonate treated Mycobacterium tuberculosis. Tuberculosis (Edinb) 2018; 111:154-160. [PMID: 30029902 DOI: 10.1016/j.tube.2018.06.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 05/29/2018] [Accepted: 06/07/2018] [Indexed: 01/03/2023]
Abstract
Over the past 5 years, there has been a renewed interest in finding new compounds with anti-TB action. Colistin methanesulfonate or polymyxin E, is a possible anti-TB drug candidate, which may in future be used either alone or in combination to the current 6 month "directly observed treatment short-course" (DOTS) regimen. However its mechanism of action has to date not yet been fully explored, and only described from a histological and genomics perspective. Considering this, we used a GCxGC-TOFMS metabolomics approach and identified those metabolite markers characterising Mycobacterium tuberculosis (Mtb) cultured in the presence of colistin methanesulfonate, in order to better understand or confirm its mechanism of action. The metabolite markers identified indicated a flux in the metabolism of the colistin methanesulfonate treated Mtb towards fatty acid synthesis and cell wall repair, confirming previous reports that colistin acts by disrupting the cell wall of mycobacteria. Accompanying this, is a subsequently elevated glucose uptake, since the latter now serves as the primary energy substrate for the upregulated glyoxylate cycle, and additionally as a precursor for further fatty acid synthesis via the glycerolipid metabolic pathway. Furthermore, the elevated concentrations of those metabolites associated with pentose phosphate, valine, threonine, and pentanediol metabolism, also confirms a shift towards glucose utilization for energy production, in the colistin methanesulfonate treated Mtb.
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16
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Xu N, Ye C, Chen X, Liu J, Liu L. Genome-scale metabolic modelling common cofactors metabolism in microorganisms. J Biotechnol 2017; 251:1-13. [PMID: 28385592 DOI: 10.1016/j.jbiotec.2017.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Revised: 04/02/2017] [Accepted: 04/03/2017] [Indexed: 12/20/2022]
Abstract
The common cofactors ATP/ADP, NAD(P)(H), and acetyl-CoA/CoA are indispensable participants in biochemical reactions in industrial microbes. To systematically explore the effects of these cofactors on cell growth and metabolic phenotypes, the first genome-scale cofactor metabolic model, icmNX6434, including 6434 genes, 1782 metabolites, and 6877 reactions, was constructed from 14 genome-scale metabolic models of 14 industrial strains. The origin, consumption, and interactions of these common cofactors in microbial cells were elucidated by the icmNX6434 model, and they played important roles in cell growth. The essential cofactor modules contained 2480 genes and 2948 reactions; therefore, improving cofactor biosynthesis, directing these cofactors into essential metabolic pathways, as well as avoiding cofactor utilization during byproduct biosynthesis and futile cycles, are three ways to increase cell growth. The effects of these common cofactors on the distribution and rate of the carbon flux in four universal modes, as well as an optimized metabolic flux, could be obtained by manipulating cofactor availability and balance. Significant changes in the ATP, NAD(H), NADP(H), or acetyl-CoA concentrations triggered relevant metabolic responses to acidic, oxidative, heat, and osmotic stress. Globally, the model icmNX6434 provides a comprehensive platform to elucidate the physiological effects of these cofactors on cell growth, metabolic flux, and industrial robustness. Moreover, the results of this study are a further example of using a consensus genome-scale metabolic model to increase our understanding of key biological processes.
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Affiliation(s)
- Nan Xu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, Jiangsu 225009, China; The Laboratory of Food Microbial-Manufacturing Engineering, Jiangnan University, Wuxi 214122, China
| | - Chao Ye
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; The Laboratory of Food Microbial-Manufacturing Engineering, Jiangnan University, Wuxi 214122, China
| | - Xiulai Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; The Laboratory of Food Microbial-Manufacturing Engineering, Jiangnan University, Wuxi 214122, China
| | - Jia Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; The Laboratory of Food Microbial-Manufacturing Engineering, Jiangnan University, Wuxi 214122, China
| | - Liming Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; The Laboratory of Food Microbial-Manufacturing Engineering, Jiangnan University, Wuxi 214122, China.
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17
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Guo W, Sheng J, Feng X. Synergizing 13C Metabolic Flux Analysis and Metabolic Engineering for Biochemical Production. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2017; 162:265-299. [PMID: 28424826 DOI: 10.1007/10_2017_2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Metabolic engineering of industrial microorganisms to produce chemicals, fuels, and drugs has attracted increasing interest as it provides an environment-friendly and renewable route that does not depend on depleting petroleum sources. However, the microbial metabolism is so complex that metabolic engineering efforts often have difficulty in achieving a satisfactory yield, titer, or productivity of the target chemical. To overcome this challenge, 13C Metabolic Flux Analysis (13C-MFA) has been developed to investigate rigorously the cell metabolism and quantify the carbon flux distribution in central metabolic pathways. In the past decade, 13C-MFA has been widely used in academic labs and the biotechnology industry to pinpoint the key issues related to microbial-based chemical production and to guide the development of the appropriate metabolic engineering strategies for improving the biochemical production. In this chapter we introduce the basics of 13C-MFA and illustrate how 13C-MFA has been applied to synergize with metabolic engineering to identify and tackle the rate-limiting steps in biochemical production.
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Affiliation(s)
- Weihua Guo
- Department of Biological Systems Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
| | - Jiayuan Sheng
- Department of Biological Systems Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
| | - Xueyang Feng
- Department of Biological Systems Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA.
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18
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Ma W, Wang J, Li Y, Hu X, Shi F, Wang X. Enhancing pentose phosphate pathway in Corynebacterium glutamicum to improve l-isoleucine production. Biotechnol Appl Biochem 2016; 63:877-885. [PMID: 27010514 DOI: 10.1002/bab.1442] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 08/26/2015] [Indexed: 11/09/2022]
Abstract
Three genes, gnd, pgl, and fbp, relevant to the pentose phosphate pathway (PPP) were overexpressed in Corynebacterium glutamicum IWJ001, leading to increase of l-isoleucine production. The transcriptional levels of gnd, pgl, and fbp significantly increased in IWJ001/pDXW-8-gnd-fbp-pgl. Compared with the control strain IWJ001/pDXW-8, intracellular NADPH/NADP+ ratios in IWJ001/pDXW-8-gnd and IWJ001/pDXW-8-gnd-fbp cells grown for 36 H increased threefold and fourfold, respectively, indicating that overexpression of gnd and fbp redirected the carbon flux to PPP. Intracellular NADPH/NADP+ ratio in IWJ001/pDXW-8-gnd-fbp-pgl grown for 36 H was similar to IWJ001/pDXW-8, suggesting that the NADPH produced by PPP could be quickly consumed for l-isoleucine production. 10.9 and 28.96 g/L of l-isoleucine was produced in IWJ001/pDXW-8-gnd-fbp-pgl in shake flask cultivation and fed-batch fermentation, respectively. In addition, IWJ001/pDXW-8-gnd-fbp-pgl grew fast, its dry cell weight reached 49 g/L after 48 H, whereas the start strain IWJ001/pDXW-8 reached only 40 g/L. After 96 H fermentation, l-isoleucine yield on glucose in IWJ001/pDXW-8-gnd-fbp-pgl reached 0.138 g/g. The results demonstrate that carbon flux redirection to PPP is an efficient approach to enhance l-isoleucine production in C. glutamicum.
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Affiliation(s)
- Wenjian Ma
- School of Biotechnology, Jiangnan University, Wuxi, People's Republic of China
| | - Jianli Wang
- School of Biotechnology, Jiangnan University, Wuxi, People's Republic of China
| | - Ye Li
- School of Biotechnology, Jiangnan University, Wuxi, People's Republic of China.,State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, People's Republic of China
| | - Xiaoqing Hu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, People's Republic of China.,Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, People's Republic of China
| | - Feng Shi
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, People's Republic of China.,Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, People's Republic of China
| | - Xiaoyuan Wang
- School of Biotechnology, Jiangnan University, Wuxi, People's Republic of China.,State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, People's Republic of China.,Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, People's Republic of China
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19
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13C-Metabolic Flux Analysis: An Accurate Approach to Demystify Microbial Metabolism for Biochemical Production. Bioengineering (Basel) 2015; 3:bioengineering3010003. [PMID: 28952565 PMCID: PMC5597161 DOI: 10.3390/bioengineering3010003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 12/10/2015] [Accepted: 12/18/2015] [Indexed: 12/15/2022] Open
Abstract
Metabolic engineering of various industrial microorganisms to produce chemicals, fuels, and drugs has raised interest since it is environmentally friendly, sustainable, and independent of nonrenewable resources. However, microbial metabolism is so complex that only a few metabolic engineering efforts have been able to achieve a satisfactory yield, titer or productivity of the target chemicals for industrial commercialization. In order to overcome this challenge, 13C Metabolic Flux Analysis (13C-MFA) has been continuously developed and widely applied to rigorously investigate cell metabolism and quantify the carbon flux distribution in central metabolic pathways. In the past decade, many 13C-MFA studies have been performed in academic labs and biotechnology industries to pinpoint key issues related to microbe-based chemical production. Insightful information about the metabolic rewiring has been provided to guide the development of the appropriate metabolic engineering strategies for improving the biochemical production. In this review, we will introduce the basics of 13C-MFA and illustrate how 13C-MFA has been applied via integration with metabolic engineering to identify and tackle the rate-limiting steps in biochemical production for various host microorganisms
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20
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Qian X, Kumaraswamy GK, Zhang S, Gates C, Ananyev GM, Bryant DA, Dismukes GC. Inactivation of nitrate reductase alters metabolic branching of carbohydrate fermentation in the cyanobacterium Synechococcus sp. strain PCC 7002. Biotechnol Bioeng 2015; 113:979-88. [PMID: 26479976 DOI: 10.1002/bit.25862] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 10/07/2015] [Accepted: 10/13/2015] [Indexed: 11/07/2022]
Abstract
To produce cellular energy, cyanobacteria reduce nitrate as the preferred pathway over proton reduction (H2 evolution) by catabolizing glycogen under dark anaerobic conditions. This competition lowers H2 production by consuming a large fraction of the reducing equivalents (NADPH and NADH). To eliminate this competition, we constructed a knockout mutant of nitrate reductase, encoded by narB, in Synechococcus sp. PCC 7002. As expected, ΔnarB was able to take up intracellular nitrate but was unable to reduce it to nitrite or ammonia, and was unable to grow photoautotrophically on nitrate. During photoautotrophic growth on urea, ΔnarB significantly redirects biomass accumulation into glycogen at the expense of protein accumulation. During subsequent dark fermentation, metabolite concentrations--both the adenylate cellular energy charge (∼ATP) and the redox poise (NAD(P)H/NAD(P))--were independent of nitrate availability in ΔnarB, in contrast to the wild type (WT) control. The ΔnarB strain diverted more reducing equivalents from glycogen catabolism into reduced products, mainly H2 and d-lactate, by 6-fold (2.8% yield) and 2-fold (82.3% yield), respectively, than WT. Continuous removal of H2 from the fermentation medium (milking) further boosted net H2 production by 7-fold in ΔnarB, at the expense of less excreted lactate, resulting in a 49-fold combined increase in the net H2 evolution rate during 2 days of fermentation compared to the WT. The absence of nitrate reductase eliminated the inductive effect of nitrate addition on rerouting carbohydrate catabolism from glycolysis to the oxidative pentose phosphate (OPP) pathway, indicating that intracellular redox poise and not nitrate itself acts as the control switch for carbon flux branching between pathways.
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Affiliation(s)
- Xiao Qian
- Waksman Institute, Rutgers University, New Brunswick, New Jersey.,Department of Microbiology and Biochemistry, Rutgers University, New Brunswick, New Jersey
| | | | - Shuyi Zhang
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, Pennsylvania
| | - Colin Gates
- Waksman Institute, Rutgers University, New Brunswick, New Jersey
| | | | - Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, Pennsylvania.,Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana
| | - G Charles Dismukes
- Waksman Institute, Rutgers University, New Brunswick, New Jersey. .,Department of Chemistry and Biological Chemistry, Rutgers University, New Brunswick, New Jersey, 08901.
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21
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Jo BH, Cha HJ. Activation of formate hydrogen-lyase via expression of uptake [NiFe]-hydrogenase in Escherichia coli BL21(DE3). Microb Cell Fact 2015; 14:151. [PMID: 26395073 PMCID: PMC4578252 DOI: 10.1186/s12934-015-0343-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Accepted: 09/16/2015] [Indexed: 11/27/2022] Open
Abstract
Background Several recent studies have reported successful hydrogen (H2) production achieved via recombinant expression of uptake [NiFe]-hydrogenases from Hydrogenovibrio marinus, Rhodobacter sphaeroides, and Escherichia coli (hydrogenase-1) in E. coli BL21(DE3), a strain that lacks H2-evolving activity. However, there are some unclear points that do not support the conclusion that the recombinant hydrogenases are responsible for the in vivo H2 production. Results Unlike wild-type BL21(DE3), the recombinant BL21(DE3) strains possessed formate hydrogen-lyase (FHL) activities. Through experiments using fdhF (formate dehydrogenase-H) or hycE (hydrogenase-3) mutants, it was shown that H2 production was almost exclusively dependent on FHL. Upon expression of hydrogenase, extracellular formate concentration was changed even in the mutant strains lacking FHL, indicating that formate metabolism other than FHL was also affected. The two subunits of H. marinus uptake [NiFe]-hydrogenase could activate FHL independently of each other, implying the presence of more than two different mechanisms for FHL activation in BL21(DE3). It was also revealed that the signal peptide in the small subunit was essential for activation of FHL via the small subunit. Conclusions Herein, we demonstrated that the production of H2 was indeed induced via native FHL activated by the expression of recombinant hydrogenases. The recombinant strains with [NiFe]-hydrogenase appear to be unsuitable for practical in vivo H2 production due to their relatively low H2 yields and productivities. We suggest that an improved H2-producing cell factory could be designed by constructing a well characterized and overproduced synthetic H2 pathway and fully activating the native FHL in BL21(DE3).
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Affiliation(s)
- Byung Hoon Jo
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 790-784, Korea.
| | - Hyung Joon Cha
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 790-784, Korea.
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22
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Spaans SK, Weusthuis RA, van der Oost J, Kengen SWM. NADPH-generating systems in bacteria and archaea. Front Microbiol 2015; 6:742. [PMID: 26284036 PMCID: PMC4518329 DOI: 10.3389/fmicb.2015.00742] [Citation(s) in RCA: 197] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 07/06/2015] [Indexed: 12/22/2022] Open
Abstract
Reduced nicotinamide adenine dinucleotide phosphate (NADPH) is an essential electron donor in all organisms. It provides the reducing power that drives numerous anabolic reactions, including those responsible for the biosynthesis of all major cell components and many products in biotechnology. The efficient synthesis of many of these products, however, is limited by the rate of NADPH regeneration. Hence, a thorough understanding of the reactions involved in the generation of NADPH is required to increase its turnover through rational strain improvement. Traditionally, the main engineering targets for increasing NADPH availability have included the dehydrogenase reactions of the oxidative pentose phosphate pathway and the isocitrate dehydrogenase step of the tricarboxylic acid (TCA) cycle. However, the importance of alternative NADPH-generating reactions has recently become evident. In the current review, the major canonical and non-canonical reactions involved in the production and regeneration of NADPH in prokaryotes are described, and their key enzymes are discussed. In addition, an overview of how different enzymes have been applied to increase NADPH availability and thereby enhance productivity is provided.
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Affiliation(s)
| | - Ruud A. Weusthuis
- Bioprocess Engineering, Wageningen UniversityWageningen, Netherlands
| | - John van der Oost
- Laboratory of Microbiology, Wageningen UniversityWageningen, Netherlands
| | - Servé W. M. Kengen
- Laboratory of Microbiology, Wageningen UniversityWageningen, Netherlands
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23
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Whitaker WB, Sandoval NR, Bennett RK, Fast AG, Papoutsakis ET. Synthetic methylotrophy: engineering the production of biofuels and chemicals based on the biology of aerobic methanol utilization. Curr Opin Biotechnol 2015; 33:165-75. [PMID: 25796071 DOI: 10.1016/j.copbio.2015.01.007] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 12/24/2014] [Accepted: 01/19/2015] [Indexed: 10/23/2022]
Abstract
Synthetic methylotrophy is the development of non-native methylotrophs that can utilize methane and methanol as sole carbon and energy sources or as co-substrates with carbohydrates to produce metabolites as biofuels and chemicals. The availability of methane (from natural gas) and its oxidation product, methanol, has been increasing, while prices have been decreasing, thus rendering them as attractive fermentation substrates. As they are more reduced than most carbohydrates, methane and methanol, as co-substrates, can enhance the yields of biologically produced metabolites. Here we discuss synthetic biology and metabolic engineering strategies based on the native biology of aerobic methylotrophs for developing synthetic strains grown on methanol, with Escherichia coli as the prototype.
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Affiliation(s)
- William B Whitaker
- Department of Chemical and Biomolecular Engineering & The Delaware Biotechnology Institute, University of Delaware, 15 Innovation Way, Newark, DE 19711, USA
| | - Nicholas R Sandoval
- Department of Chemical and Biomolecular Engineering & The Delaware Biotechnology Institute, University of Delaware, 15 Innovation Way, Newark, DE 19711, USA
| | - Robert K Bennett
- Department of Chemical and Biomolecular Engineering & The Delaware Biotechnology Institute, University of Delaware, 15 Innovation Way, Newark, DE 19711, USA
| | - Alan G Fast
- Department of Chemical and Biomolecular Engineering & The Delaware Biotechnology Institute, University of Delaware, 15 Innovation Way, Newark, DE 19711, USA
| | - Eleftherios T Papoutsakis
- Department of Chemical and Biomolecular Engineering & The Delaware Biotechnology Institute, University of Delaware, 15 Innovation Way, Newark, DE 19711, USA; Department of Biological Sciences, University of Delaware, USA.
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Liu P, Zhu X, Tan Z, Zhang X, Ma Y. Construction of Escherichia Coli Cell Factories for Production of Organic Acids and Alcohols. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2015; 155:107-40. [PMID: 25577396 DOI: 10.1007/10_2014_294] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Production of bulk chemicals from renewable biomass has been proved to be sustainable and environmentally friendly. Escherichia coli is the most commonly used host strain for constructing cell factories for production of bulk chemicals since it has clear physiological and genetic characteristics, grows fast in minimal salts medium, uses a wide range of substrates, and can be genetically modified easily. With the development of metabolic engineering, systems biology, and synthetic biology, a technology platform has been established to construct E. coli cell factories for bulk chemicals production. In this chapter, we will introduce this technology platform, as well as E. coli cell factories successfully constructed for production of organic acids and alcohols.
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Affiliation(s)
- Pingping Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, 32 West 7th Ave, Tianjin Airport Economic Area, Tianjin, 300308, China
| | - Xinna Zhu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, 32 West 7th Ave, Tianjin Airport Economic Area, Tianjin, 300308, China
| | - Zaigao Tan
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, 32 West 7th Ave, Tianjin Airport Economic Area, Tianjin, 300308, China.,University of Chinese Academy of Sciences, Tianjin, China
| | - Xueli Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China. .,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, 32 West 7th Ave, Tianjin Airport Economic Area, Tianjin, 300308, China.
| | - Yanhe Ma
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
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Qi H, Li S, Zhao S, Huang D, Xia M, Wen J. Model-driven redox pathway manipulation for improved isobutanol production in Bacillus subtilis complemented with experimental validation and metabolic profiling analysis. PLoS One 2014; 9:e93815. [PMID: 24705866 PMCID: PMC3976320 DOI: 10.1371/journal.pone.0093815] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 03/06/2014] [Indexed: 12/05/2022] Open
Abstract
To rationally guide the improvement of isobutanol production, metabolic network and metabolic profiling analysis were performed to provide global and profound insights into cell metabolism of isobutanol-producing Bacillus subtilis. The metabolic flux distribution of strains with different isobutanol production capacity (BSUL03, BSUL04 and BSUL05) drops a hint of the importance of NADPH on isobutanol biosynthesis. Therefore, the redox pathways were redesigned in this study. To increase NADPH concentration, glucose-6-phosphate isomerase was inactivated (BSUL06) and glucose-6-phosphate dehydrogenase was overexpressed (BSUL07) successively. As expected, NADPH pool size in BSUL07 was 4.4-fold higher than that in parental strain BSUL05. However, cell growth, isobutanol yield and production were decreased by 46%, 22%, and 80%, respectively. Metabolic profiling analysis suggested that the severely imbalanced redox status might be the primary reason. To solve this problem, gene udhA of Escherichia coli encoding transhydrogenase was further overexpressed (BSUL08), which not only well balanced the cellular ratio of NAD(P)H/NAD(P)+, but also increased NADH and ATP concentration. In addition, a straightforward engineering approach for improving NADPH concentrations was employed in BSUL05 by overexpressing exogenous gene pntAB and obtained BSUL09. The performance for isobutanol production by BSUL09 was poorer than BSUL08 but better than other engineered strains. Furthermore, in fed-batch fermentation the isobutanol production and yield of BSUL08 increased by 11% and 19%, up to the value of 6.12 g/L and 0.37 C-mol isobutanol/C-mol glucose (63% of the theoretical value), respectively, compared with parental strain BSUL05. These results demonstrated that model-driven complemented with metabolic profiling analysis could serve as a useful approach in the strain improvement for higher bio-productivity in further application.
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Affiliation(s)
- Haishan Qi
- Key Laboratory of System Bioengineering, Ministry of Education, Tianjin University, Tianjin, People's Republic of China
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
| | - Shanshan Li
- Key Laboratory of System Bioengineering, Ministry of Education, Tianjin University, Tianjin, People's Republic of China
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
| | - Sumin Zhao
- Key Laboratory of System Bioengineering, Ministry of Education, Tianjin University, Tianjin, People's Republic of China
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
| | - Di Huang
- Key Laboratory of System Bioengineering, Ministry of Education, Tianjin University, Tianjin, People's Republic of China
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
| | - Menglei Xia
- Key Laboratory of System Bioengineering, Ministry of Education, Tianjin University, Tianjin, People's Republic of China
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
| | - Jianping Wen
- Key Laboratory of System Bioengineering, Ministry of Education, Tianjin University, Tianjin, People's Republic of China
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, People's Republic of China
- * E-mail:
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Predictive combinatorial design of mRNA translation initiation regions for systematic optimization of gene expression levels. Sci Rep 2014; 4:4515. [PMID: 24682040 PMCID: PMC3970122 DOI: 10.1038/srep04515] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 03/13/2014] [Indexed: 01/03/2023] Open
Abstract
Balancing the amounts of enzymes is one of the important factors to achieve optimum performance of a designed metabolic pathway. However, the random mutagenesis approach is impractical since it requires searching an unnecessarily large number of variants and often results in searching a narrow range of expression levels which are out of optimal level. Here, we developed a predictive combinatorial design method, called UTR Library Designer, which systematically searches a large combinatorial space of expression levels. It accomplishes this by designing synthetic translation initiation region of mRNAs in a predictive way based on a thermodynamic model and genetic algorithm. Using this approach, we successfully enhanced lysine and hydrogen production in Escherichia coli. Our method significantly reduced the number of variants to be explored for covering large combinatorial space and efficiently enhanced pathway efficiency, thereby facilitating future efforts in metabolic engineering and synthetic biology.
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Wecker MSA, Ghirardi ML. High-throughput biosensor discriminates between different algal H2 -photoproducing strains. Biotechnol Bioeng 2014; 111:1332-40. [PMID: 24578287 DOI: 10.1002/bit.25206] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 01/15/2014] [Accepted: 01/28/2014] [Indexed: 12/24/2022]
Abstract
A number of species of microalgae and cyanobacteria photosynthetically produce H2 gas by coupling water oxidation with the reduction of protons to molecular hydrogen, generating renewable energy from sunlight and water. Photosynthetic H2 production, however, is transitory, and there is considerable interest in increasing and extending it for commercial applications. Here we report a Petri-plate version of our previous, microplate-based assay that detects photosynthetic H2 production by algae. The assay consists of an agar overlay of H2 -sensing Rhodobacter capsulatus bacteria carrying a green fluorescent protein that responds to H2 produced by single algal colonies in the bottom agar layer. The assay distinguishes between algal strains that photoproduce H2 at different levels under high light intensities, and it does so in a simple, inexpensive, and high-throughput manner. The assay will be useful for screening both natural populations and mutant libraries for strains having increased H2 production, and useful for identifying various genetic factors that physiologically or genetically alter algal hydrogen production.
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Ghosh D, Bisaillon A, Hallenbeck PC. Increasing the metabolic capacity of Escherichia coli for hydrogen production through heterologous expression of the Ralstonia eutropha SH operon. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:122. [PMID: 23977944 PMCID: PMC3765991 DOI: 10.1186/1754-6834-6-122] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 08/21/2013] [Indexed: 06/01/2023]
Abstract
BACKGROUND Fermentative hydrogen production is an attractive means for the sustainable production of this future energy carrier but is hampered by low yields. One possible solution is to create, using metabolic engineering, strains which can bypass the normal metabolic limits to substrate conversion to hydrogen. Escherichia coli can degrade a variety of sugars to hydrogen but can only convert electrons available at the pyruvate node to hydrogen, and is unable to use the electrons available in NADH generated during glycolysis. RESULTS Here, the heterologous expression of the soluble [NiFe] hydrogenase from Ralstonia eutropha H16 (the SH hydrogenase) was used to demonstrate the introduction of a pathway capable of deriving substantial hydrogen from the NADH generated by fermentation. Successful expression was demonstrated by in vitro assay of enzyme activity. Moreover, expression of SH restored anaerobic growth on glucose to adhE strains, normally blocked for growth due to the inability to re-oxidize NADH. Measurement of in vivo hydrogen production showed that several metabolically engineered strains were capable of using the SH hydrogenase to derive 2 mol H2 per mol of glucose consumed, close to the theoretical maximum. CONCLUSION Previous introduction of heterologous [NiFe] hydrogenase in E. coli led to NAD(P)H dependent activity, but hydrogen production levels were very low. Here we have shown for the first time substantial in vivo hydrogen production by a heterologously expressed [NiFe] hydrogenase, the soluble NAD-dependent H2ase of R. eutropha (SH hydrogenase). This hydrogenase was able to couple metabolically generated NADH to hydrogen production, thus rescuing an alcohol dehydrogenase (adhE) mutant. This enlarges the range of metabolism available for hydrogen production, thus potentially opening the door to the creation of greatly improved hydrogen production. Strategies for further increasing yields should revolve around making additional NADH available.
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Affiliation(s)
- Dipankar Ghosh
- Département de Microbiologie et Immunologie, Université de Montréal, CP 6128 Succursale Centre-ville, Montréal, Québec, Canada H3C 3J7
| | - Ariane Bisaillon
- Département de Microbiologie et Immunologie, Université de Montréal, CP 6128 Succursale Centre-ville, Montréal, Québec, Canada H3C 3J7
| | - Patrick C Hallenbeck
- Département de Microbiologie et Immunologie, Université de Montréal, CP 6128 Succursale Centre-ville, Montréal, Québec, Canada H3C 3J7
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Pawar SS, van Niel EWJ. Thermophilic biohydrogen production: how far are we? Appl Microbiol Biotechnol 2013; 97:7999-8009. [PMID: 23948723 PMCID: PMC3757257 DOI: 10.1007/s00253-013-5141-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 07/16/2013] [Accepted: 07/17/2013] [Indexed: 01/10/2023]
Abstract
Apart from being applied as an energy carrier, hydrogen is in increasing demand as a commodity. Currently, the majority of hydrogen (H2) is produced from fossil fuels, but from an environmental perspective, sustainable H2 production should be considered. One of the possible ways of hydrogen production is through fermentation, in particular, at elevated temperature, i.e. thermophilic biohydrogen production. This short review recapitulates the current status in thermophilic biohydrogen production through fermentation of commercially viable substrates produced from readily available renewable resources, such as agricultural residues. The route to commercially viable biohydrogen production is a multidisciplinary enterprise. Microbiological studies have pointed out certain desirable physiological characteristics in H2-producing microorganisms. More process-oriented research has identified best applicable reactor types and cultivation conditions. Techno-economic and life cycle analyses have identified key process bottlenecks with respect to economic feasibility and its environmental impact. The review has further identified current limitations and gaps in the knowledge, and also deliberates directions for future research and development of thermophilic biohydrogen production.
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Affiliation(s)
- Sudhanshu S Pawar
- Applied Microbiology, Lund University, Getingevägen 60, 222 41, Lund, Sweden.
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Wang Y, San KY, Bennett GN. Cofactor engineering for advancing chemical biotechnology. Curr Opin Biotechnol 2013; 24:994-9. [PMID: 23611567 DOI: 10.1016/j.copbio.2013.03.022] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 03/21/2013] [Accepted: 03/22/2013] [Indexed: 11/26/2022]
Abstract
Cofactors provide redox carriers for biosynthetic reactions, catabolic reactions and act as important agents in transfer of energy for the cell. Recent advances in manipulating cofactors include culture conditions or additive alterations, genetic modification of host pathways for increased availability of desired cofactor, changes in enzyme cofactor specificity, and introduction of novel redox partners to form effective circuits for biochemical processes and biocatalysts. Genetic strategies to employ ferredoxin, NADH and NADPH most effectively in natural or novel pathways have improved yield and efficiency of large-scale processes for fuels and chemicals and have been demonstrated with a variety of microbial organisms.
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Affiliation(s)
- Yipeng Wang
- Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77005, USA
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31
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Wang Y, San KY, Bennett GN. Improvement of NADPH bioavailability in Escherichia coli through the use of phosphofructokinase deficient strains. Appl Microbiol Biotechnol 2013; 97:6883-93. [PMID: 23558585 DOI: 10.1007/s00253-013-4859-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 03/11/2013] [Accepted: 03/13/2013] [Indexed: 11/26/2022]
Abstract
NADPH-dependent reactions play important roles in production of industrially valuable compounds. In this study, we used phosphofructokinase (PFK)-deficient strains to direct fructose-6-phosphate to be oxidized through the pentose phosphate pathway (PPP) to increase NADPH generation. pfkA or pfkB single deletion and double-deletion strains were tested for their ability to produce lycopene. Since lycopene biosynthesis requires many NADPH, levels of lycopene were compared in a set of isogenic strains, with the pfkA single deletion strain showing the highest lycopene yield. Using another NADPH-requiring process, a one-step reduction reaction of 2-chloroacrylate to 2-chloropropionic acid by 2-haloacrylate reductase, the pfkA pfkB double-deletion strain showed the highest yield of 2-chloropropionic acid product. The combined effect of glucose-6-phosphate dehydrogenase overexpression or lactate dehydrogenase deletion with PFK deficiency on NADPH bioavailability was also studied. The results indicated that the flux distribution of fructose-6-phosphate between glycolysis and the pentose phosphate pathway determines the amount of NAPDH available for reductive biosynthesis.
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Affiliation(s)
- Yipeng Wang
- Department of Biochemistry and Cell Biology, MS-140, Rice University, 6100 Main Street, Houston, TX 77005-1892, USA
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32
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Fang H, Xie X, Xu Q, Zhang C, Chen N. Enhancement of cytidine production by coexpression of gnd, zwf, and prs genes in recombinant Escherichia coli CYT15. Biotechnol Lett 2012; 35:245-51. [PMID: 23070626 DOI: 10.1007/s10529-012-1068-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2012] [Accepted: 10/04/2012] [Indexed: 11/28/2022]
Abstract
Cytidine is a precursor of several antiviral drugs. The pentose phosphate pathway (PPP) is primarily responsible for NADPH and 5-phospho-α-D-ribose 1-diphosphate as an important precursor of cytidine biosynthesis in Escherichia coli. To enhance cytidine production, we obtained the recombinant E. coli CYT15-gnd-prs-zwf that co-expressed the prs, zwf, and gnd genes encoding phosphoribosylpyrophosphate synthetase, glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase (three key enzymes in PPP) respectively. In fermentation experiments, strain CYT15-gnd-prs-zwf produced 735 mg cytidine/l using glucose as substrate, which was approx. 128 % higher than the cytidine production by the parental strain (CYT15). Co-expression of zwf, gnd, and prs decreased growth (3.2 %) slightly and increased glucose uptake (72 %). This is the first study to report increased cytidine production by increasing metabolic flux through the PPP in E. coli.
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Affiliation(s)
- Haitian Fang
- Metabolic Engineering Laboratory, College of Biotechnology, Tianjin University of Science & Technology, No. 29 13 Main Street, Tianjin Economic and Technological Development Zone, Tianjin, China.
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Rittmann S, Herwig C. A comprehensive and quantitative review of dark fermentative biohydrogen production. Microb Cell Fact 2012; 11:115. [PMID: 22925149 PMCID: PMC3443015 DOI: 10.1186/1475-2859-11-115] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 08/03/2012] [Indexed: 01/25/2023] Open
Abstract
Biohydrogen production (BHP) can be achieved by direct or indirect biophotolysis, photo-fermentation and dark fermentation, whereof only the latter does not require the input of light energy. Our motivation to compile this review was to quantify and comprehensively report strains and process performance of dark fermentative BHP. This review summarizes the work done on pure and defined co-culture dark fermentative BHP since the year 1901. Qualitative growth characteristics and quantitative normalized results of H2 production for more than 2000 conditions are presented in a normalized and therefore comparable format to the scientific community.Statistically based evidence shows that thermophilic strains comprise high substrate conversion efficiency, but mesophilic strains achieve high volumetric productivity. Moreover, microbes of Thermoanaerobacterales (Family III) have to be preferred when aiming to achieve high substrate conversion efficiency in comparison to the families Clostridiaceae and Enterobacteriaceae. The limited number of results available on dark fermentative BHP from fed-batch cultivations indicates the yet underestimated potential of this bioprocessing application. A Design of Experiments strategy should be preferred for efficient bioprocess development and optimization of BHP aiming at improving medium, cultivation conditions and revealing inhibitory effects. This will enable comparing and optimizing strains and processes independent of initial conditions and scale.
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Affiliation(s)
- Simon Rittmann
- Institute of Chemical Engineering, Research Area Biochemical Engineering, Gumpendorferstraße 1a, Vienna University of Technology, Vienna, 1060, Austria
| | - Christoph Herwig
- Institute of Chemical Engineering, Research Area Biochemical Engineering, Gumpendorferstraße 1a, Vienna University of Technology, Vienna, 1060, Austria
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Rational engineering of enzyme allosteric regulation through sequence evolution analysis. PLoS Comput Biol 2012; 8:e1002612. [PMID: 22807670 PMCID: PMC3395594 DOI: 10.1371/journal.pcbi.1002612] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 05/29/2012] [Indexed: 12/04/2022] Open
Abstract
Control of enzyme allosteric regulation is required to drive metabolic flux toward desired levels. Although the three-dimensional (3D) structures of many enzyme-ligand complexes are available, it is still difficult to rationally engineer an allosterically regulatable enzyme without decreasing its catalytic activity. Here, we describe an effective strategy to deregulate the allosteric inhibition of enzymes based on the molecular evolution and physicochemical characteristics of allosteric ligand-binding sites. We found that allosteric sites are evolutionarily variable and comprised of more hydrophobic residues than catalytic sites. We applied our findings to design mutations in selected target residues that deregulate the allosteric activity of fructose-1,6-bisphosphatase (FBPase). Specifically, charged amino acids at less conserved positions were substituted with hydrophobic or neutral amino acids with similar sizes. The engineered proteins successfully diminished the allosteric inhibition of E. coli FBPase without affecting its catalytic efficiency. We expect that our method will aid the rational design of enzyme allosteric regulation strategies and facilitate the control of metabolic flux. Design of allosterically regulatable enzyme is essential to develop a highly efficient metabolite production. However, mutations on allosteric ligand binding sites often disrupt the catalytic activity of enzyme. To aid the design process of allosterically controllable enzymes, we develop an effective computational strategy to deregulate the allosteric inhibition of enzymes based on sequence evolution analysis of allosteric ligand-binding sites. We analyzed the molecular evolution and amino acid composition of catalytic and allosteric sites of enzymes, and discovered that allosteric sites are evolutionarily variable and comprised of more hydrophobic residues than catalytic sites. We then experimentally tested our strategy of enzyme allosteric regulation and found that the designed mutations effectively deregulated allosteric inhibition of FBPase. We believe that our method will aid the rational design of enzyme allosteric regulation and help to facilitate control of metabolic flux.
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Cho HS, Seo SW, Kim YM, Jung GY, Park JM. Engineering glyceraldehyde-3-phosphate dehydrogenase for switching control of glycolysis in Escherichia coli. Biotechnol Bioeng 2012; 109:2612-9. [PMID: 22528318 DOI: 10.1002/bit.24532] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 03/20/2012] [Accepted: 04/13/2012] [Indexed: 11/06/2022]
Abstract
Glycolysis has evolved to be a highly robust mechanism for maintaining the cellular metabolism of living organisms. However, relevant modifications of glycolytic activity are required to intentionally modulate cellular phenotypes. Here, we designed a platform that allows switching control of glycolysis in Escherichia coli in response to an environmental signal, in this case, temperature. This system functions by regulating the expression of gapA, which encodes glyceraldehyde-3-phosphate dehydrogenase (GAPDH), one of the key glycolytic enzymes. Because a very low level of gapA expression is capable of maintaining cellular physiology, we also modified GAPDH through directed evolution to provide sensitive regulation of glycolytic activity. The switching control of glycolysis was successfully demonstrated by regulating the expression of engineered gapA through changes in temperature. This system offers potential control over the cell's central carbon-metabolism switch, providing the ability to perform reprogrammed tasks with desired timing depending on environmental signals.
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Affiliation(s)
- Han-Saem Cho
- Department of Chemical Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Nam-gu, Pohang, Gyeong-buk 790-784, South Korea
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Recent advances in engineering the central carbon metabolism of industrially important bacteria. Microb Cell Fact 2012; 11:50. [PMID: 22545791 PMCID: PMC3461431 DOI: 10.1186/1475-2859-11-50] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 04/30/2012] [Indexed: 01/19/2023] Open
Abstract
This paper gives an overview of the recent advances in engineering the central carbon metabolism of the industrially important bacteria Escherichia coli, Bacillus subtilis, Corynobacterium glutamicum, Streptomyces spp., Lactococcus lactis and other lactic acid bacteria. All of them are established producers of important classes of products, e.g. proteins, amino acids, organic acids, antibiotics, high-value metabolites for the food industry and also, promising producers of a large number of industrially or therapeutically important chemicals. Optimization of existing or introduction of new cellular processes in these microorganisms is often achieved through manipulation of targets that reside at major points of central metabolic pathways, such as glycolysis, gluconeogenesis, the pentose phosphate pathway and the tricarboxylic acid cycle with the glyoxylate shunt. Based on the huge progress made in recent years in biochemical, genetic and regulatory studies, new fascinating engineering approaches aim at ensuring an optimal carbon and energy flow within central metabolism in order to achieve optimized metabolite production.
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37
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Hallenbeck PC, Abo-Hashesh M, Ghosh D. Strategies for improving biological hydrogen production. BIORESOURCE TECHNOLOGY 2012; 110:1-9. [PMID: 22342581 DOI: 10.1016/j.biortech.2012.01.103] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 01/15/2012] [Accepted: 01/19/2012] [Indexed: 05/21/2023]
Abstract
Biological hydrogen production presents a possible avenue for the large scale sustainable generation of hydrogen needed to fuel a future hydrogen economy. Amongst the possible approaches that are under active investigation and that will be briefly discussed; biophotolysis, photofermentation, microbial electrolysis, and dark fermentation, dark fermentation has the additional advantages of largely relying on already developed bioprocess technology and of potentially using various waste streams as feedstock. However, the major roadblock to developing a practical process has been the low yields, typically around 25%, well below those achievable for the production of other biofuels from the same feedstocks. Moreover, low yields also lead to the generation of side products whose large scale production would generate a waste disposal problem. Here recent attempts to overcome these barriers are reviewed and recent progress in efforts to increase hydrogen yields through physiological manipulation, metabolic engineering and the use of two-stage systems are described.
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Affiliation(s)
- Patrick C Hallenbeck
- Département de microbiologie et immunologie, Université de Montréal, CP 6128, Centre-ville, Montréal, Canada PQ H3C 3J7.
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Kontur WS, Noguera DR, Donohue TJ. Maximizing reductant flow into microbial H2 production. Curr Opin Biotechnol 2011; 23:382-9. [PMID: 22036711 DOI: 10.1016/j.copbio.2011.10.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 10/03/2011] [Accepted: 10/04/2011] [Indexed: 01/08/2023]
Abstract
Developing microbes into a sustainable source of hydrogen gas (H2) will require maximizing intracellular reductant flow toward the H2-producing enzymes. Recent attempts to increase H2 production in dark fermentative bacteria include increasing oxidation of organic substrates through metabolic engineering and expression of exogenous hydrogenases. In photofermentative bacteria, H2 production can be increased by minimizing reductant flow into competing pathways such as biomass formation and the Calvin cycle. One method of directing reductant toward H2 production being investigated in oxygenic phototrophs, which could potentially be applied to other H2-producing organisms, is the tethering of electron donors and acceptors, such as hydrogenase and photosystem I, to create new intermolecular electron transfer pathways.
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Affiliation(s)
- Wayne S Kontur
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, United States; DOE Great Lakes Bioenergy Research Center, Madison, WI, United States
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