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Gecse G, Labunskaite R, Pedersen M, Kilstrup M, Johanson T. Minimizing acetate formation from overflow metabolism in Escherichia coli: comparison of genetic engineering strategies to improve robustness toward sugar gradients in large-scale fermentation processes. Front Bioeng Biotechnol 2024; 12:1339054. [PMID: 38419731 PMCID: PMC10899681 DOI: 10.3389/fbioe.2024.1339054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 01/15/2024] [Indexed: 03/02/2024] Open
Abstract
Introduction: Escherichia coli, a well characterized workhorse in biotechnology, has been used to produce many recombinant proteins and metabolites, but have a major drawback in its tendency to revert to overflow metabolism. This phenomenon occurs when excess sugar triggers the production of mainly acetate under aerobic conditions, a detrimental by-product that reduces carbon efficiency, increases cell maintenance, and ultimately inhibits growth. Although this can be prevented by controlled feeding of the sugar carbon source to limit its availability, gradients in commercial-scale bioreactors can still induce it in otherwise carbon-limited cells. While the underlying mechanisms have been extensively studied, these have mostly used non-limited cultures. In contrast, industrial production typically employs carbon-limited processes, which results in a substantially different cell physiology. Objective: The objective of this study was to evaluate and compare the efficiency of different metabolic engineering strategies with the aim to reduce overflow metabolism and increase the robustness of an industrial 2'-O-fucosyllactose producing strain under industrially relevant conditions. Methods: Three distinct metabolic engineering strategies were compared: i) alterations to pathways leading to and from acetate, ii) increased flux towards the tricarboxylic acid (TCA) cycle, and iii) reduced glucose uptake rate. The engineered strains were evaluated for growth, acetate formation, and product yield under non-limiting batch conditions, carbon limited fed-batch conditions, and after a glucose pulse in fed-batch mode. Results and Discussion: The findings demonstrated that blockage of the major acetate production pathways by deletion of the pta and poxB genes or increased carbon flux into the TCA cycle by overexpression of the gltA and deletion of the iclR genes, were efficient ways to reduce acetate accumulation. Surprisingly, a reduced glucose uptake rate did not reduce acetate formation despite it having previously been shown as a very effective strategy. Interestingly, overexpression of gltA was the most efficient way to reduce acetate accumulation in non-limited cultures, whereas disruption of the poxB and pta genes was more effective for carbon-limited cultures exposed to a sudden glucose shock. Strains from both strategies showed increased tolerance towards a glucose pulse during carbon-limited growth indicating feasible ways to engineer industrial E. coli strains with enhanced robustness.
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Affiliation(s)
| | | | | | - Mogens Kilstrup
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
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Mund M, Weber W, Degreif D, Schiklenk C. A MAD7-based genome editing system for Escherichia coli. Microb Biotechnol 2023; 16:1000-1010. [PMID: 36929689 PMCID: PMC10128132 DOI: 10.1111/1751-7915.14234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 01/29/2023] [Accepted: 01/31/2023] [Indexed: 03/18/2023] Open
Abstract
A broad variety of biomolecules is industrially produced in bacteria and yeasts. These microbial expression hosts can be optimized through genetic engineering using CRISPR tools. Here, we designed and characterized such a modular genome editing system based on the Cas12a-like RNA-guided nuclease MAD7 in Escherichia coli. This system enables the efficient generation of single nucleotide polymorphisms (SNPs) or gene deletions and can directly be used with donor DNA from benchtop DNA assembly to increase throughput. We combined multiple edits to engineer an E. coli strain with reduced overflow metabolism and increased plasmid yield, highlighting the versatility and industrial applicability of this approach.
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Affiliation(s)
- Markus Mund
- Sanofi-Aventis Deutschland GmbH, Global CMC Microbial Platform, USP Development - Molecular Biology, Frankfurt am Main, Germany
| | - Wadim Weber
- Sanofi-Aventis Deutschland GmbH, Global CMC Microbial Platform, USP Development - Molecular Biology, Frankfurt am Main, Germany
| | - Daniel Degreif
- Sanofi-Aventis Deutschland GmbH, Global CMC Microbial Platform, USP Development - Molecular Biology, Frankfurt am Main, Germany
| | - Christoph Schiklenk
- Sanofi-Aventis Deutschland GmbH, Global CMC Microbial Platform, USP Development - Molecular Biology, Frankfurt am Main, Germany
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Kiefer D, Tadele LR, Lilge L, Henkel M, Hausmann R. High-level recombinant protein production with Corynebacterium glutamicum using acetate as carbon source. Microb Biotechnol 2022; 15:2744-2757. [PMID: 36178056 PMCID: PMC9618323 DOI: 10.1111/1751-7915.14138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 08/24/2022] [Indexed: 11/27/2022] Open
Abstract
In recent years, biotechnological conversion of the alternative carbon source acetate has attracted much attention. So far, acetate has been mainly used for microbial production of bioproducts with bulk applications. In this study, we aimed to investigate the potential of acetate as carbon source for heterologous protein production using the acetate-utilizing platform organism Corynebacterium glutamicum. For this purpose, expression of model protein eYFP with the promoter systems T7lac and tac was characterized during growth of C. glutamicum on acetate as sole carbon source. The results indicated a 3.3-fold higher fluorescence level for acetate-based eYFP production with T7 expression strain MB001(DE3) pMKEx2-eyfp compared to MB001 pEKEx2-eyfp. Interestingly, comparative eyfp expression studies on acetate or glucose revealed an up to 83% higher biomass-specific production for T7 RNAP-dependent eYFP production using acetate as carbon source. Furthermore, high-level protein accumulation on acetate was demonstrated for the first time in a high cell density cultivation process with pH-coupled online feeding control, resulting in a final protein titer of 2.7 g/L and product yield of 4 g per 100 g cell dry weight. This study presents a first proof of concept for efficient microbial upgrading of potentially low-cost acetate into high-value bioproducts, such as recombinant proteins.
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Affiliation(s)
- Dirk Kiefer
- Department of Bioprocess EngineeringInstitute of Food Science and Biotechnology, University of HohenheimStuttgartGermany
| | - Lea Rahel Tadele
- Department of Bioprocess EngineeringInstitute of Food Science and Biotechnology, University of HohenheimStuttgartGermany
| | - Lars Lilge
- Department of Bioprocess EngineeringInstitute of Food Science and Biotechnology, University of HohenheimStuttgartGermany
| | - Marius Henkel
- Cellular AgricultureTUM School of Life Sciences, Technical University of MunichFreisingGermany
| | - Rudolf Hausmann
- Department of Bioprocess EngineeringInstitute of Food Science and Biotechnology, University of HohenheimStuttgartGermany
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Fragoso-Jiménez JC, Gutierrez-Rios RM, Flores N, Martinez A, Lara AR, Delvigne F, Gosset G. Glucose consumption rate-dependent transcriptome profiling of Escherichia coli provides insight on performance as microbial factories. Microb Cell Fact 2022; 21:189. [PMID: 36100849 PMCID: PMC9472385 DOI: 10.1186/s12934-022-01909-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 08/27/2022] [Indexed: 11/21/2022] Open
Abstract
Background The modification of glucose import capacity is an engineering strategy that has been shown to improve the characteristics of Escherichia coli as a microbial factory. A reduction in glucose import capacity can have a positive effect on production strain performance, however, this is not always the case. In this study, E. coli W3110 and a group of four isogenic derivative strains, harboring single or multiple deletions of genes encoding phosphoenolpyruvate:sugar phosphotransferase system (PTS)-dependent transporters as well as non-PTS transporters were characterized by determining their transcriptomic response to reduced glucose import capacity. Results These strains were grown in bioreactors with M9 mineral salts medium containing 20 g/L of glucose, where they displayed specific growth rates ranging from 0.67 to 0.27 h−1, and specific glucose consumption rates (qs) ranging from 1.78 to 0.37 g/g h. RNA-seq analysis revealed a transcriptional response consistent with carbon source limitation among all the mutant strains, involving functions related to transport and metabolism of alternate carbon sources and characterized by a decrease in genes encoding glycolytic enzymes and an increase in gluconeogenic functions. A total of 107 and 185 genes displayed positive and negative correlations with qs, respectively. Functions displaying positive correlation included energy generation, amino acid biosynthesis, and sugar import. Conclusion Changes in gene expression of E. coli strains with impaired glucose import capacity could be correlated with qs values and this allowed an inference of the physiological state of each mutant. In strains with lower qs values, a gene expression pattern is consistent with energy limitation and entry into the stationary phase. This physiological state could explain why these strains display a lower capacity to produce recombinant protein, even when they show very low rates of acetate production. The comparison of the transcriptomes of the engineered strains employed as microbial factories is an effective approach for identifying favorable phenotypes with the potential to improve the synthesis of biotechnological products. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-022-01909-y.
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Affiliation(s)
- Juan Carlos Fragoso-Jiménez
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos, Cuernavaca, México
| | - Rosa María Gutierrez-Rios
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos, Cuernavaca, México
| | - Noemí Flores
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos, Cuernavaca, México
| | - Alfredo Martinez
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos, Cuernavaca, México
| | - Alvaro R Lara
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana, Ciudad de Mexico, México
| | - Frank Delvigne
- Terra Research and Teaching Centre, Microbial Processes and Interactions (MiPI) Gembloux Agro‑Bio Tech, University of Liège, Gembloux, Belgium
| | - Guillermo Gosset
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos, Cuernavaca, México.
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Chiang CJ, Hu MC, Ta T, Chao YP. Glutamate as a non-conventional substrate for high production of the recombinant protein in Escherichia coli. Front Microbiol 2022; 13:991963. [PMID: 36187956 PMCID: PMC9515452 DOI: 10.3389/fmicb.2022.991963] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 08/23/2022] [Indexed: 11/13/2022] Open
Abstract
The economic viability of the biomass-based biorefinery is readily acknowledged by implementation of a cascade process that produces value-added products such as enzymes prior to biofuels. Proteins from the waste stream of biorefinery processes generally contain glutamate (Glu) in abundance. Accordingly, this study was initiated to explore the potential of Glu for production of recombinant proteins in Escherichia coli. The approach was first adopted by expression of D-hydantoinase (HDT) in commercially-available BL21(DE3) strain. Equipped with the mutant gltS (gltS*), the strain grown on Glu produced the maximum HDT as compared to the counterpart on glucose, glycerol, or acetate. The Glu-based production scheme was subsequently reprogrammed based on the L-arabinose-regulated T7 expression system. The strain with gltS* was further engineered by rewiring metabolic pathways. With low ammonium, the resulting strain produced 1.63-fold more HDT. The result indicates that Glu can serve as a carbon and nitrogen source. Overall, our proposed approach may open up a new avenue for the enzyme biorefinery platform based on Glu.
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Affiliation(s)
- Chung-Jen Chiang
- Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung, Taiwan
| | - Mu-Chen Hu
- Department of Chemical Engineering, Feng Chia University, Taichung, Taiwan
| | - Thanh Ta
- Department of Chemical Engineering, Feng Chia University, Taichung, Taiwan
| | - Yun-Peng Chao
- Department of Chemical Engineering, Feng Chia University, Taichung, Taiwan
- Department of Medical Research, China Medical University Hospital, Taichung, Taiwan
- Department of Food Nutrition and Health Biotechnology, Asia University, Taichung, Taiwan
- *Correspondence: Yun-Peng Chao,
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Genome-scale metabolic model-based engineering of Escherichia coli enhances recombinant single-chain antibody fragment production. Biotechnol Lett 2022; 44:1231-1242. [PMID: 36074282 DOI: 10.1007/s10529-022-03301-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 08/29/2022] [Indexed: 11/02/2022]
Abstract
PURPOSE Escherichia coli is an attractive and cost-effective cell factory for producing recombinant proteins such as single-chain variable fragments (scFvs). AntiEpEX-scFv is a small antibody fragment that has received considerable attention for its ability to target the epithelial cell adhesion molecule (EpCAM), a cancer-associated biomarker of solid tumors. Due to its metabolic burden, scFv recombinant expression causes a remarkable decrease in the maximum specific growth rate of the scFv-producing strain. In the present study, a genome-scale metabolic model (GEM)-guided engineering strategy is proposed to identify gene targets for improved antiEpEX-scFv production in E. coli. METHODS In this study, a genome-scale metabolic model of E. coli (iJO1366) and a metabolic modeling tool (FVSEOF) were employed to find appropriate genes to be amplified in order to improve the strain for incresed production of antiEpEX-scFv. To validate the model predictions, one target gene was overexpressed in the parent strain Escherichia coli BW25113 (DE3). RESULTS For improving scFv production, we applied the FVSEOF method to identify a number of potential genetic engineering targets. These targets were found to be localized in the glucose uptake system and pentose phosphate pathway. From the predicted targets, the glk gene encoding glucokinase was chosen to be overexpressed in the parent strain Escherichia coli BW25113 (DE3). By overexpressing glk, the growth capacity of the recombinant E. coli strain was recovered. Moreover, the engineered strain with glk overexpression successfully led to increased scFv production. CONCLUSION The genome-scale metabolic modeling can be considered for the improvement of the production of other recombinant proteins.
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Taymaz-Nikerel H, Lara AR. Vitreoscilla Haemoglobin: A Tool to Reduce Overflow Metabolism. Microorganisms 2021; 10:microorganisms10010043. [PMID: 35056491 PMCID: PMC8779101 DOI: 10.3390/microorganisms10010043] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/18/2021] [Accepted: 12/20/2021] [Indexed: 11/26/2022] Open
Abstract
Overflow metabolism is a phenomenon extended in nature, ranging from microbial to cancer cells. Accumulation of overflow metabolites pose a challenge for large-scale bioprocesses. Yet, the causes of overflow metabolism are not fully clarified. In this work, the underlying mechanisms, reasons and consequences of overflow metabolism in different organisms have been summarized. The reported effect of aerobic expression of Vitreoscilla haemoglobin (VHb) in different organisms are revised. The use of VHb to reduce overflow metabolism is proposed and studied through flux balance analysis in E. coli at a fixed maximum substrate and oxygen uptake rates. Simulations showed that the presence of VHb increases the growth rate, while decreasing acetate production, in line with the experimental measurements. Therefore, aerobic VHb expression is considered a potential tool to reduce overflow metabolism in cells.
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Affiliation(s)
- Hilal Taymaz-Nikerel
- Department of Genetics and Bioengineering, Istanbul Bilgi University, İstanbul 34060, Turkey;
| | - Alvaro R. Lara
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana, Mexico City 05348, Mexico
- Correspondence:
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Tao YM, Bu CY, Zou LH, Hu YL, Zheng ZJ, Ouyang J. A comprehensive review on microbial production of 1,2-propanediol: micro-organisms, metabolic pathways, and metabolic engineering. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:216. [PMID: 34794503 PMCID: PMC8600716 DOI: 10.1186/s13068-021-02067-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 11/07/2021] [Indexed: 06/13/2023]
Abstract
1,2-Propanediol is an important building block as a component used in the manufacture of unsaturated polyester resin, antifreeze, biofuel, nonionic detergent, etc. Commercial production of 1,2-propanediol through microbial biosynthesis is limited by low efficiency, and chemical production of 1,2-propanediol requires petrochemically derived routes involving wasteful power consumption and high pollution emissions. With the development of various strategies based on metabolic engineering, a series of obstacles are expected to be overcome. This review provides an extensive overview of the progress in the microbial production of 1,2-propanediol, particularly the different micro-organisms used for 1,2-propanediol biosynthesis and microbial production pathways. In addition, outstanding challenges associated with microbial biosynthesis and feasible metabolic engineering strategies, as well as perspectives on the future microbial production of 1,2-propanediol, are discussed.
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Affiliation(s)
- Yuan-Ming Tao
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, 210037, People's Republic of China
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, People's Republic of China
| | - Chong-Yang Bu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, 210037, People's Republic of China
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, People's Republic of China
| | - Li-Hua Zou
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, 210037, People's Republic of China
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, People's Republic of China
| | - Yue-Li Hu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, 210037, People's Republic of China
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, People's Republic of China
| | - Zhao-Juan Zheng
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, 210037, People's Republic of China
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, People's Republic of China
| | - Jia Ouyang
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, 210037, People's Republic of China.
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, People's Republic of China.
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Zhu F, Peña M, Bennett GN. Metabolic engineering of Escherichia coli for quinolinic acid production by assembling L-aspartate oxidase and quinolinate synthase as an enzyme complex. Metab Eng 2021; 67:164-172. [PMID: 34192552 PMCID: PMC10024596 DOI: 10.1016/j.ymben.2021.06.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 04/23/2021] [Accepted: 06/21/2021] [Indexed: 10/21/2022]
Abstract
Quinolinic acid (QA) is a key intermediate of nicotinic acid (Niacin) which is an essential human nutrient and widely used in food and pharmaceutical industries. In this study, a quinolinic acid producer was constructed by employing comprehensive engineering strategies. Firstly, the quinolinic acid production was improved by deactivation of NadC (to block the consumption pathway), NadR (to eliminate the repression of L-aspartate oxidase and quinolinate synthase), and PtsG (to slow the glucose utilization rate and achieve a more balanced metabolism, and also to increase the availability of the precursor phosphoenolpyruvate). Further modifications to enhance quinolinic acid production were investigated by increasing the oxaloacetate pool through overproduction of phosphoenolpyruvate carboxylase and deactivation of acetate-producing pathway enzymes. Moreover, quinolinic acid production was accelerated by assembling NadB and NadA as an enzyme complex with the help of peptide-peptide interaction peptides RIAD and RIDD, which resulted in up to 3.7 g/L quinolinic acid being produced from 40 g/L glucose in shake-flask cultures. A quinolinic acid producer was constructed in this study, and these results lay a foundation for further engineering of microbial cell factories to efficiently produce quinolinic acid and subsequently convert this product to nicotinic acid for industrial applications.
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Affiliation(s)
- Fayin Zhu
- Department of BioSciences, Rice University, Houston, TX, 77005, USA
| | - Matthew Peña
- Department of BioSciences, Rice University, Houston, TX, 77005, USA
| | - George N Bennett
- Department of BioSciences, Rice University, Houston, TX, 77005, USA; Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, 77005, USA.
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10
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Lu Y, Cheng X, Deng H, Chen S, Ji Z. Improvement of 1-deoxynojirimycin production of Bacillus amyloliquefaciens by gene overexpression and medium optimization. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.111812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Ziegler M, Zieringer J, Döring CL, Paul L, Schaal C, Takors R. Engineering of a robust Escherichia coli chassis and exploitation for large-scale production processes. Metab Eng 2021; 67:75-87. [PMID: 34098100 DOI: 10.1016/j.ymben.2021.05.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 05/30/2021] [Accepted: 05/31/2021] [Indexed: 11/28/2022]
Abstract
In large-scale bioprocesses microbes are exposed to heterogeneous substrate availability reducing the overall process performance. A series of deletion strains was constructed from E. coli MG1655 aiming for a robust phenotype in heterogeneous fermentations with transient starvation. Deletion targets were hand-picked based on a list of genes derived from previous large-scale simulation runs. Each gene deletion was conducted on the premise of strict neutrality towards growth parameters in glucose minimal medium. The final strain of the series, named E. coli RM214, was cultivated continuously in an STR-PFR (stirred tank reactor - plug flow reactor) scale-down reactor. The scale-down reactor system simulated repeated passages through a glucose starvation zone. When exposed to nutrient gradients, E. coli RM214 had a significantly lower maintenance coefficient than E. coli MG1655 (Δms = 0.038 gGlucose/gCDW/h, p < 0.05). In an exemplary protein production scenario E. coli RM214 remained significantly more productive than E. coli MG1655 reaching 44% higher eGFP yield after 28 h of STR-PFR cultivation. This study developed E. coli RM214 as a robust chassis strain and demonstrated the feasibility of engineering microbial hosts for large-scale applications.
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Affiliation(s)
- Martin Ziegler
- University of Stuttgart - Institute of Biochemical Engineering, Allmandring 31, 70569, Stuttgart, Germany.
| | - Julia Zieringer
- University of Stuttgart - Institute of Biochemical Engineering, Allmandring 31, 70569, Stuttgart, Germany.
| | - Clarissa-Laura Döring
- University of Stuttgart - Institute of Biochemical Engineering, Allmandring 31, 70569, Stuttgart, Germany.
| | - Liv Paul
- University of Stuttgart - Institute of Biochemical Engineering, Allmandring 31, 70569, Stuttgart, Germany.
| | - Christoph Schaal
- University of Stuttgart - Institute of Biochemical Engineering, Allmandring 31, 70569, Stuttgart, Germany.
| | - Ralf Takors
- University of Stuttgart - Institute of Biochemical Engineering, Allmandring 31, 70569, Stuttgart, Germany.
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12
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Folch PL, Bisschops MM, Weusthuis RA. Metabolic energy conservation for fermentative product formation. Microb Biotechnol 2021; 14:829-858. [PMID: 33438829 PMCID: PMC8085960 DOI: 10.1111/1751-7915.13746] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 12/16/2020] [Accepted: 12/21/2020] [Indexed: 12/02/2022] Open
Abstract
Microbial production of bulk chemicals and biofuels from carbohydrates competes with low-cost fossil-based production. To limit production costs, high titres, productivities and especially high yields are required. This necessitates metabolic networks involved in product formation to be redox-neutral and conserve metabolic energy to sustain growth and maintenance. Here, we review the mechanisms available to conserve energy and to prevent unnecessary energy expenditure. First, an overview of ATP production in existing sugar-based fermentation processes is presented. Substrate-level phosphorylation (SLP) and the involved kinase reactions are described. Based on the thermodynamics of these reactions, we explore whether other kinase-catalysed reactions can be applied for SLP. Generation of ion-motive force is another means to conserve metabolic energy. We provide examples how its generation is supported by carbon-carbon double bond reduction, decarboxylation and electron transfer between redox cofactors. In a wider perspective, the relationship between redox potential and energy conservation is discussed. We describe how the energy input required for coenzyme A (CoA) and CO2 binding can be reduced by applying CoA-transferases and transcarboxylases. The transport of sugars and fermentation products may require metabolic energy input, but alternative transport systems can be used to minimize this. Finally, we show that energy contained in glycosidic bonds and the phosphate-phosphate bond of pyrophosphate can be conserved. This review can be used as a reference to design energetically efficient microbial cell factories and enhance product yield.
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Affiliation(s)
- Pauline L. Folch
- Bioprocess EngineeringWageningen University & ResearchPost office box 16Wageningen6700 AAThe Netherlands
| | - Markus M.M. Bisschops
- Bioprocess EngineeringWageningen University & ResearchPost office box 16Wageningen6700 AAThe Netherlands
| | - Ruud A. Weusthuis
- Bioprocess EngineeringWageningen University & ResearchPost office box 16Wageningen6700 AAThe Netherlands
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Castillo Alfonso F, Vigueras-Ramírez G, Rosales-Colunga LM, Del Monte-Martínez A, Olivares Hernández R. Propionate as the preferred carbon source to produce 3-indoleacetic acid in B. subtilis: comparative flux analysis using five carbon sources. Mol Omics 2021; 17:554-564. [PMID: 33972977 DOI: 10.1039/d1mo00039j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
3-Indoleacetic acid (IAA) is a phytohormone that promotes plant root growth, improving the use of nutrients and crop yield and it is been reported that bacteria of the genus Bacillus are capable of producing this phytohormone under various growth conditions. Considering this metabolic capability, in this work, Bacillus subtilis was cultivated in five different carbon sources: glucose, acetate, propionate, citrate and glycerol; and l-tryptophan (Trp) was used as an inducer for the IAA production. Based on the experimental results it was observed that the highest growth rate was achieved using glucose as a carbon source (μ = 0.12 h-1) and the lowest value was for citrate (μ = 0.08 h-1). On the other hand, the highest IAA production was obtained using propionate Yp/s = 0.975 (gIAA gTrp-1) and the lowest was when glucose was the substrate Yp/s = 0.803 (gIAA gTrp-1). In order to explore the metabolism and understand these differences, the experimental data was used to calculate the flux distribution using the genomic-scale metabolic model of Bacillus subtilis. Performing a comparative analysis it is observed that the fluxes towards precursors increase when propionate is the carbon source.
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Affiliation(s)
- Freddy Castillo Alfonso
- Posgrado en Ciencias Naturales e Ingeniería, Universidad Autónoma Metropolitana, Unidad Cuajimalpa, Av. Vasco de Quiroga 4871, Col. Santa Fe Cuajimalpa, Delegación Cuajimalpa, Ciudad de Mexico, 05348, Mexico
| | - Gabriel Vigueras-Ramírez
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana, Unidad Cuajimalpa, Av. Vasco de Quiroga 4871, Col. Santa Fe Cuajimalpa, Delegación Cuajimalpa, Ciudad de Mexico, 05348, Mexico.
| | - Luis Manuel Rosales-Colunga
- Facultad de Ingeniería, Universidad Autónoma de San Luis Potosí, Av. Dr Manuel Nava 8, Zona Universitaria, 78290, San Luis Potosí, S.L.P, Mexico
| | - Alberto Del Monte-Martínez
- Centro de Estudios de Proteínas, Univerisdad de La Habana, Calle 25 #455, e/J e I, vedado, 10400, Havana, Cuba
| | - Roberto Olivares Hernández
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana, Unidad Cuajimalpa, Av. Vasco de Quiroga 4871, Col. Santa Fe Cuajimalpa, Delegación Cuajimalpa, Ciudad de Mexico, 05348, Mexico.
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Chiang CJ, Ho YJ, Hu MC, Chao YP. Rewiring of glycerol metabolism in Escherichia coli for effective production of recombinant proteins. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:205. [PMID: 33317614 PMCID: PMC7737366 DOI: 10.1186/s13068-020-01848-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 12/03/2020] [Indexed: 06/12/2023]
Abstract
BACKGROUND The economic viability of a protein-production process relies highly on the production titer and the price of raw materials. Crude glycerol coming from the production of biodiesel is a renewable and cost-effective resource. However, glycerol is inefficiently utilized by Escherichia coli. RESULTS This issue was addressed by rewiring glycerol metabolism for redistribution of the metabolic flux. Key steps in central metabolism involving the glycerol dissimilation pathway, the pentose phosphate pathway, and the tricarboxylic acid cycle were pinpointed and manipulated to provide precursor metabolites and energy. As a result, the engineered E. coli strain displayed a 9- and 30-fold increase in utilization of crude glycerol and production of the target protein, respectively. CONCLUSIONS The result indicates that the present method of metabolic engineering is useful and straightforward for efficient adjustment of the flux distribution in glycerol metabolism. The practical application of this methodology in biorefinery and the related field would be acknowledged.
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Affiliation(s)
- Chung-Jen Chiang
- Department of Medical Laboratory Science and Biotechnology, China Medical University, No. 91, Hsueh-Shih Road, Taichung, 40402 Taiwan
| | - Yi-Jing Ho
- Department of Chemical Engineering, Feng Chia University, 100 Wenhwa Road, Taichung, 40724 Taiwan
| | - Mu-Chen Hu
- Department of Chemical Engineering, Feng Chia University, 100 Wenhwa Road, Taichung, 40724 Taiwan
| | - Yun-Peng Chao
- Department of Chemical Engineering, Feng Chia University, 100 Wenhwa Road, Taichung, 40724 Taiwan
- Department of Medical Research, China Medical University Hospital, Taichung, 40447 Taiwan
- Department of Food Nutrition and Health Biotechnology, Asia University, Taichung, 41354 Taiwan
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15
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Ortega-Quintana FA, Trujillo-Roldán MA, Botero-Castro H, Alvarez H. Modeling the interaction between the central carbon metabolism of Escherichia coli and bioreactor culture media. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2020.107753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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16
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Chiang CJ, Hu MC, Chao YP. A Strategy to Improve Production of Recombinant Proteins in Escherichia coli Based on a Glucose-Glycerol Mixture and Glutamate. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:8883-8889. [PMID: 32806130 DOI: 10.1021/acs.jafc.0c03671] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Enzymes have a wide range of applications in many sectors of the industry, and the market value has skyrocketed in recent years. Glucose and glycerol are two renewable carbon sources of importance. Therefore, it is appealing to produce recombinant enzymes with these carbon substrates on the basis of economic viability. In this study, glycerol metabolism and glucose metabolism in Escherichia coli (E. coli) were manipulated in a systematic way. In addition, glutamate (Glu) was used for replacement of yeast extract to reduce the cost and the quality-variation problem. A strategy was further developed to incorporate Glu into the central metabolism. The engineered E. coli strain finally enabled efficient co-utilization of glucose and glycerol and improved biomass and protein production by 4.3 and 8.2-folds, respectively. The result illustrates that this proposed approach is promising for effective production of recombinant proteins.
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Affiliation(s)
- Chung-Jen Chiang
- Department of Medical Laboratory Science and Biotechnology, China Medical University, No. 91, Hsueh-Shih Road, Taichung 40402, Taiwan
| | - Mu-Chen Hu
- Department of Chemical Engineering, Feng Chia University, 100 Wenhwa Road, Taichung 40724, Taiwan
| | - Yun-Peng Chao
- Department of Chemical Engineering, Feng Chia University, 100 Wenhwa Road, Taichung 40724, Taiwan
- Department of Medical Research, China Medical University Hospital, Taichung 40447, Taiwan
- Department of Health and Nutrition Biotechnology, Asia University, Taichung 41354, Taiwan
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17
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Zhang J, Zhao Y, Cao Y, Yu Z, Wang G, Li Y, Ye X, Li C, Lin X, Song H. Synthetic sRNA-Based Engineering of Escherichia coli for Enhanced Production of Full-Length Immunoglobulin G. Biotechnol J 2020; 15:e1900363. [PMID: 32034883 DOI: 10.1002/biot.201900363] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 11/06/2019] [Indexed: 12/18/2022]
Abstract
Production of monoclonal antibodies (mAbs) receives considerable attention in the pharmaceutical industry. There has been an increasing interest in the expression of mAbs in Escherichia coli for analytical and therapeutic applications in recent years. Here, a modular synthetic biology approach is developed to rationally engineer E. coli by designing three functional modules to facilitate high-titer production of immunoglobulin G (IgG). First, a bicistronic expression system is constructed and the expression of the key genes in the pyruvate metabolism is tuned by the technologies of synthetic sRNA translational repression and gene overexpression, thus enhancing the cellular material and energy metabolism of E. coli for IgG biosynthesis (module 1). Second, to prevent the IgG biodegradation by proteases, the expression of a number of key proteases is identified and inhibited via synthetic sRNAs (module 2). Third, molecular chaperones are co-expressed to promote the secretion and folding of IgG (module 3). Synergistic integration of the three modules into the resulting recombinant E. coli results in a yield of the full-length IgG ≈150 mg L-1 in a 5L fed-batch bioreactor. The modular synthetic biology approach could be of general use in the production of recombinant mAbs.
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Affiliation(s)
- Jinhua Zhang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE) , School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, P. R. China
| | - Yanshu Zhao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE) , School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, P. R. China
| | - Yingxiu Cao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE) , School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, P. R. China
| | - Zhenpeng Yu
- Yangzhou Lianao Biopharmaceutical Co. Ltd., and Yangzhou Aurisco Pharmaceutical Co. Ltd., Wanmei Road No. 5, Hanjiang Economic Development Zone, Yangzhou, Jiangsu, 225100, P. R. China
| | - Guoping Wang
- Yangzhou Lianao Biopharmaceutical Co. Ltd., and Yangzhou Aurisco Pharmaceutical Co. Ltd., Wanmei Road No. 5, Hanjiang Economic Development Zone, Yangzhou, Jiangsu, 225100, P. R. China
| | - Yiqun Li
- Yangzhou Lianao Biopharmaceutical Co. Ltd., and Yangzhou Aurisco Pharmaceutical Co. Ltd., Wanmei Road No. 5, Hanjiang Economic Development Zone, Yangzhou, Jiangsu, 225100, P. R. China
| | - Xiaoqiong Ye
- Yangzhou Lianao Biopharmaceutical Co. Ltd., and Yangzhou Aurisco Pharmaceutical Co. Ltd., Wanmei Road No. 5, Hanjiang Economic Development Zone, Yangzhou, Jiangsu, 225100, P. R. China
| | - Congfa Li
- College of Food Science and Technology, Hainan University, Haikou, 570228, P. R. China
| | - Xue Lin
- College of Food Science and Technology, Hainan University, Haikou, 570228, P. R. China
| | - Hao Song
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE) , School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, P. R. China
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18
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Wang J, Shang Q, Zhao C, Zhang S, Li Z, Lin C, Shen Z, Cheng L. Improvement of Streptococcus suis glutamate dehydrogenase expression in Escherichia coli through genetic modification of acetate synthesis pathway. Lett Appl Microbiol 2019; 70:64-70. [PMID: 31665809 DOI: 10.1111/lam.13244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 10/25/2019] [Accepted: 10/25/2019] [Indexed: 12/26/2022]
Abstract
Escherichia coli generates acetate as an undesirable by-product that has several negative effects on protein expression, and the reduction of acetate accumulation by modifying genes of acetate synthesis pathway can improve the expression of recombinant proteins. In the present study, the effect of phosphotransacetylase (pta) or/and acetate kinase (ackA) deletion on glutamate dehydrogenase (GDH) expression was investigated. The results indicated that the disruptions of pta or/and ackA decreased the acetate accumulation and synthesis of per gram cell, and increased cell density, and GDH expression and synthesis of per gram cell. The pta gene was more important for acetate formation than the ackA gene. Using the strain with deletions of pta-ackA (SSGPA) for GDH expression, acetate accumulation (2·61 g l-1 ) and acetate synthesis of per gram cell (0·229 g g-1 ) were lowest, decreasing by 28·29 and 41·43% compared with those of the parental strain (SSG) respectively. The flux of acetate synthesis (6·6%) was decreased by 72·15% compared with that of SSG, and the highest cell density (11·38 g l-1 ), GDH expression (2·78 mg ml-1 ), and GDH formation of per gram cell (0·2442 mg mg-1 ) were obtained, which were 1·22-, 1·43- and 1·17-times higher than the parental strain respectively. SIGNIFICANCE AND IMPACT OF THE STUDY: Significance and Impact of the Study: Acetate is the key undesirable by-product in Escherichia coli cultivation, and both biomass and production of desired products are increased by the reduction of acetate accumulation. In the present study, the strains with deletions of pta or/and ackA were constructed to reduce the acetate accumulation and improve the GDH expression, and the highest expression level of GDH was obtained using the strain with lesion in pta-ackA that was 1·17-times higher than that of the parental strain. The construction strategy of recombinant E. coli for decreasing the acetate excretion can be used for high expression level of other desired products.
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Affiliation(s)
- J Wang
- Department of Critical Care Medicine, Affiliated Hospital of Binzhou Medical University, Binzhou, China.,Key Laboratory of Fermentation Engineering, Shandong Binzhou Animal Science and Veterinary Medicine Academy, Binzhou, China
| | - Q Shang
- Department of Critical Care Medicine, Affiliated Hospital of Binzhou Medical University, Binzhou, China
| | - C Zhao
- Research and Development Center, Ningxia Eppen Biotech Co. Ltd, Yinchuan, China
| | - S Zhang
- Key Laboratory of Fermentation Engineering, Shandong Binzhou Animal Science and Veterinary Medicine Academy, Binzhou, China.,Shandong Research Center of High Cell Density Fermentation and Efficient Expression Technology, Shandong Lvdu Bio-science and Technology Co. Ltd, Binzhou, China
| | - Z Li
- Research and Development Center, Ningxia Eppen Biotech Co. Ltd, Yinchuan, China
| | - C Lin
- Key Laboratory of Fermentation Engineering, Shandong Binzhou Animal Science and Veterinary Medicine Academy, Binzhou, China.,Research and Development Center, Ningxia Eppen Biotech Co. Ltd, Yinchuan, China
| | - Z Shen
- Key Laboratory of Fermentation Engineering, Shandong Binzhou Animal Science and Veterinary Medicine Academy, Binzhou, China.,Shandong Research Center of High Cell Density Fermentation and Efficient Expression Technology, Shandong Lvdu Bio-science and Technology Co. Ltd, Binzhou, China
| | - L Cheng
- Key Laboratory of Fermentation Engineering, Shandong Binzhou Animal Science and Veterinary Medicine Academy, Binzhou, China.,Shandong Research Center of High Cell Density Fermentation and Efficient Expression Technology, Shandong Lvdu Bio-science and Technology Co. Ltd, Binzhou, China
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19
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Perez-Zabaleta M, Guevara-Martínez M, Gustavsson M, Quillaguamán J, Larsson G, van Maris AJA. Comparison of engineered Escherichia coli AF1000 and BL21 strains for (R)-3-hydroxybutyrate production in fed-batch cultivation. Appl Microbiol Biotechnol 2019; 103:5627-5639. [PMID: 31104101 PMCID: PMC6597613 DOI: 10.1007/s00253-019-09876-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 04/18/2019] [Accepted: 04/24/2019] [Indexed: 02/06/2023]
Abstract
Accumulation of acetate is a limiting factor in recombinant production of (R)-3-hydroxybutyrate (3HB) by Escherichia coli in high-cell-density processes. To alleviate this limitation, this study investigated two approaches: (i) deletion of phosphotransacetylase (pta), pyruvate oxidase (poxB), and/or the isocitrate lyase regulator (iclR), known to decrease acetate formation, on bioreactor cultivations designed to achieve high 3HB concentrations. (ii) Screening of different E. coli strain backgrounds (B, BL21, W, BW25113, MG1655, W3110, and AF1000) for their potential as low acetate-forming, 3HB-producing platforms. Deletion of pta and pta-poxB in the AF1000 strain background was to some extent successful in decreasing acetate formation, but also dramatically increased excretion of pyruvate and did not result in increased 3HB production in high-cell-density fed-batch cultivations. Screening of the different E. coli strains confirmed BL21 as a low acetate-forming background. Despite low 3HB titers in low-cell-density screening, 3HB-producing BL21 produced five times less acetic acid per mole of 3HB, which translated into a 2.3-fold increase in the final 3HB titer and a 3-fold higher volumetric 3HB productivity over 3HB-producing AF1000 strains in nitrogen-limited fed-batch cultivations. Consequently, the BL21 strain achieved the hitherto highest described volumetric productivity of 3HB (1.52 g L−1 h−1) and the highest 3HB concentration (16.3 g L−1) achieved by recombinant E. coli. Screening solely for 3HB titers in low-cell-density batch cultivations would not have identified the potential of this strain, reaffirming the importance of screening with the final production conditions in mind.
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Affiliation(s)
- Mariel Perez-Zabaleta
- School of Engineering Sciences in Chemistry, Biotechnology, and Health (CBH), Department of Industrial Biotechnology, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden
- Center of Biotechnology, Faculty of Science and Technology, Universidad Mayor de San Simón, Cochabamba, Bolivia
| | - Mónica Guevara-Martínez
- School of Engineering Sciences in Chemistry, Biotechnology, and Health (CBH), Department of Industrial Biotechnology, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden
- Center of Biotechnology, Faculty of Science and Technology, Universidad Mayor de San Simón, Cochabamba, Bolivia
| | - Martin Gustavsson
- School of Engineering Sciences in Chemistry, Biotechnology, and Health (CBH), Department of Industrial Biotechnology, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden
| | - Jorge Quillaguamán
- Center of Biotechnology, Faculty of Science and Technology, Universidad Mayor de San Simón, Cochabamba, Bolivia
| | - Gen Larsson
- School of Engineering Sciences in Chemistry, Biotechnology, and Health (CBH), Department of Industrial Biotechnology, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden
| | - Antonius J. A. van Maris
- School of Engineering Sciences in Chemistry, Biotechnology, and Health (CBH), Department of Industrial Biotechnology, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden
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20
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Metabolic Engineering and Fermentation Process Strategies for L-Tryptophan Production by Escherichia coli. Processes (Basel) 2019. [DOI: 10.3390/pr7040213] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
L-tryptophan is an essential aromatic amino acid that has been widely used in medicine, food, and animal feed. Microbial biosynthesis of L-tryptophan through metabolic engineering approaches represents a sustainable, cost-effective, and environmentally friendly route compared to chemical synthesis. In particular, metabolic pathway engineering allows enhanced product titers by inactivating/blocking the competing pathways, increasing the intracellular level of essential precursors, and overexpressing rate-limiting enzymatic steps. Based on the route of the l-tryptophan biosynthesis pathway, this review presents a systematic and detailed summary of the contemporary metabolic engineering approaches employed for l-tryptophan production. In addition to the engineering of the l-tryptophan biosynthesis pathway, the metabolic engineering modification of carbon source uptake, by-product formation, key regulatory factors, and the polyhydroxybutyrate biosynthesis pathway in l-tryptophan biosynthesis are discussed. Moreover, fermentation bioprocess optimization strategies used for l-tryptophan overproduction are also delineated. Towards the end, the review is wrapped up with the concluding remarks, and future strategies are outlined for the development of a high l-tryptophan production strain.
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21
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Fragoso-Jiménez JC, Baert J, Nguyen TM, Liu W, Sassi H, Goormaghtigh F, Van Melderen L, Gaytán P, Hernández-Chávez G, Martinez A, Delvigne F, Gosset G. Growth-dependent recombinant product formation kinetics can be reproduced through engineering of glucose transport and is prone to phenotypic heterogeneity. Microb Cell Fact 2019; 18:26. [PMID: 30710996 PMCID: PMC6359759 DOI: 10.1186/s12934-019-1073-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 01/23/2019] [Indexed: 12/31/2022] Open
Abstract
Background Escherichia coli W3110 and a group of six isogenic derivatives, each displaying distinct specific rates of glucose consumption were characterized to determine levels of GFP production and population heterogeneity. These strains have single or combinatory deletions in genes encoding phosphoenolpyruvate:sugar phosphotransferase system (PTS) permeases as PtsG and ManX, as well as common components EI, Hpr protein and EIIA, also the non-PTS Mgl galactose/glucose ABC transporter. They have been transformed for expressing GFP based on a lac-based expression vector, which is subject to bistability. Results These strains displayed specific glucose consumption and growth rates ranging from 1.75 to 0.45 g/g h and 0.54 to 0.16 h−1, respectively. The rate of acetate production was strongly reduced in all mutant strains when compared with W3110/pV21. In bioreactor cultures, wild type W3110/pV21 produced 50.51 mg/L GFP, whereas strains WG/pV21 with inactive PTS IICBGlc and WGM/pV21 with the additional inactivation of PTS IIABMan showed the highest titers of GFP, corresponding to 342 and 438 mg/L, respectively. Moreover, we showed experimentally that bistable expression systems, as lac-based ones, induce strong phenotypic segregation among microbial populations. Conclusions We have demonstrated that reduction on glucose consumption rate in E. coli leads to an improvement of GFP production. Furthermore, from the perspective of phenotypic heterogeneity, we observed in this case that heterogeneous systems are also the ones leading to the highest performance. This observation suggests reconsidering the generally accepted proposition stating that phenotypic heterogeneity is generally unwanted in bioprocess applications.![]() Electronic supplementary material The online version of this article (10.1186/s12934-019-1073-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Juan Carlos Fragoso-Jiménez
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Jonathan Baert
- Terra Research and Teaching Centre, Microbial Processes and Interactions (MiPI), Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Thai Minh Nguyen
- Terra Research and Teaching Centre, Microbial Processes and Interactions (MiPI), Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Wenzheng Liu
- Terra Research and Teaching Centre, Microbial Processes and Interactions (MiPI), Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Hosni Sassi
- Terra Research and Teaching Centre, Microbial Processes and Interactions (MiPI), Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Frédéric Goormaghtigh
- Cellular and Molecular Microbiology (CM2), Faculté des Sciences, Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Laurence Van Melderen
- Cellular and Molecular Microbiology (CM2), Faculté des Sciences, Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Paul Gaytán
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Georgina Hernández-Chávez
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Alfredo Martinez
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Frank Delvigne
- Terra Research and Teaching Centre, Microbial Processes and Interactions (MiPI), Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium.
| | - Guillermo Gosset
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico.
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Zhu F, Wang Y, San KY, Bennett GN. Metabolic engineering of Escherichia coli to produce succinate from soybean hydrolysate under anaerobic conditions. Biotechnol Bioeng 2018; 115:1743-1754. [PMID: 29508908 DOI: 10.1002/bit.26584] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/31/2018] [Accepted: 02/02/2018] [Indexed: 01/17/2023]
Abstract
It is of great economic interest to produce succinate from low-grade carbon sources, which can enhance the competitiveness of the biological route. In this study, succinate producer Escherichia coli CT550/pHL413KF1 was further engineered to efficiently use the mixed sugars from non-food based soybean hydrolysate to produce succinate under anaerobic conditions. Since many common E. coli strains fail to use galactose anaerobically even if they can use it aerobically, the glucose, and galactose related sugar transporters were deactivated individually and evaluated. The PTS system was found to be important for utilization of mixed sugars, and galactose uptake was activated by deactivating ptsG. In the ptsG- strain, glucose, and galactose were used simultaneously. Glucose was assimilated mainly through the mannose PTS system while galactose was transferred mainly through GalP in a ptsG- strain. A new succinate producing strain, FZ591C which can efficiently produce succinate from the mixed sugars present in soybean hydrolysate was constructed by integration of the high succinate yield producing module and the galactose utilization module into the chromosome of the CT550 ptsG- strain. The succinate yield reached 1.64 mol/mol hexose consumed (95% of maximum theoretical yield) when a mixed sugars feedstock was used as a carbon source. Based on the three monitored sugars, a nominal succinate yield of 1.95 mol/mol was observed as the strain can apparently also use some other minor sugars in the hydrolysate. In this study, we demonstrate that FZ591C can use soybean hydrolysate as an inexpensive carbon source for high yield succinate production under anaerobic conditions, giving it the potential for industrial application.
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Affiliation(s)
- Fayin Zhu
- Department of BioSciences, Rice University, Houston, Texas
| | - Yuanshan Wang
- Department of BioSciences, Rice University, Houston, Texas
- Institute of Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Ka-Yiu San
- Department of Bioengineering, Rice University, Houston, Texas
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas
| | - George N Bennett
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas
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Liu R, Liang L, Garst AD, Choudhury A, Nogué VSI, Beckham GT, Gill RT. Directed combinatorial mutagenesis of Escherichia coli for complex phenotype engineering. Metab Eng 2018; 47:10-20. [DOI: 10.1016/j.ymben.2018.02.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 12/02/2017] [Accepted: 02/20/2018] [Indexed: 01/19/2023]
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Ma W, Liu Y, Shin HD, Li J, Chen J, Du G, Liu L. Metabolic engineering of carbon overflow metabolism of Bacillus subtilis for improved N-acetyl-glucosamine production. BIORESOURCE TECHNOLOGY 2018; 250:642-649. [PMID: 29220808 DOI: 10.1016/j.biortech.2017.10.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 10/02/2017] [Accepted: 10/04/2017] [Indexed: 05/09/2023]
Abstract
Bacillus subtilis is widely used as cell factories for the production of important industrial biochemicals. Although many studies have demonstrated the effects of organic acidic byproducts, such as acetate, on microbial fermentation, little is known about the effects of blocking the neutral byproduct overflow, such as acetoin, on bioproduction. In this study, we focused on the influences of modulating overflow metabolism on the production of N-acetyl-d-glucosamine (GlcNAc) in engineered B. subtilis. We found that acetoin overflow competes with GlcNAc production, and blocking acetoin overflow increased GlcNAc titer and yield by 1.38- and 1.39-fold, reaching 48.9 g/L and 0.32 g GlcNAc/g glucose, respectively. Further blocking acetate overflow inhibited cell growth and GlcNAc production may be induced by inhibiting glucose uptake. Taken together, our results show that blocking acetoin overflow is a promising strategy for enhancing GlcNAc production. The strategies developed in this work may be useful for engineering strains of B. subtilis for producing other important biochemicals.
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Affiliation(s)
- Wenlong Ma
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Yanfeng Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Hyun-Dong Shin
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta 30332, USA
| | - Jianghua Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Jian Chen
- Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Guocheng Du
- Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China.
| | - Long Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
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Eberhardt F, Aguirre A, Paoletti L, Hails G, Braia M, Ravasi P, Peiru S, Menzella HG. Pilot-scale process development for low-cost production of a thermostable biodiesel refining enzyme in Escherichia coli. Bioprocess Biosyst Eng 2018; 41:555-564. [DOI: 10.1007/s00449-018-1890-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 12/31/2017] [Indexed: 11/30/2022]
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Veeravalli K, Schindler T, Dong E, Yamada M, Hamilton R, Laird MW. Strain engineering to reduce acetate accumulation during microaerobic growth conditions inEscherichia coli. Biotechnol Prog 2017; 34:303-314. [DOI: 10.1002/btpr.2592] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 11/16/2017] [Indexed: 12/11/2022]
Affiliation(s)
- Karthik Veeravalli
- Late Stage Cell Culture, Genentech, Inc., 1 DNA Way; South San Francisco California 94080
| | - Tony Schindler
- Late Stage Cell Culture, Genentech, Inc., 1 DNA Way; South San Francisco California 94080
| | - Emily Dong
- Early Stage Cell Culture, Genentech, Inc., 1 DNA Way; South San Francisco California 94080
| | - Masaki Yamada
- Late Stage Cell Culture, Genentech, Inc., 1 DNA Way; South San Francisco California 94080
| | - Ryan Hamilton
- Late Stage Cell Culture, Genentech, Inc., 1 DNA Way; South San Francisco California 94080
| | - Michael W. Laird
- Early Stage Cell Culture, Genentech, Inc., 1 DNA Way; South San Francisco California 94080
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Gu Y, Deng J, Liu Y, Li J, Shin H, Du G, Chen J, Liu L. Rewiring the Glucose Transportation and Central Metabolic Pathways for Overproduction of
N
‐Acetylglucosamine in
Bacillus subtilis. Biotechnol J 2017; 12. [DOI: 10.1002/biot.201700020] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 06/22/2017] [Indexed: 01/21/2023]
Affiliation(s)
- Yang Gu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of EducationJiangnan UniversityWuxi214122China
- Key Laboratory of Industrial Biotechnology, Ministry of EducationJiangnan UniversityWuxi214122China
| | - Jieying Deng
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of EducationJiangnan UniversityWuxi214122China
- Key Laboratory of Industrial Biotechnology, Ministry of EducationJiangnan UniversityWuxi214122China
| | - Yanfeng Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of EducationJiangnan UniversityWuxi214122China
- Key Laboratory of Industrial Biotechnology, Ministry of EducationJiangnan UniversityWuxi214122China
| | - Jianghua Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of EducationJiangnan UniversityWuxi214122China
- Key Laboratory of Industrial Biotechnology, Ministry of EducationJiangnan UniversityWuxi214122China
| | - Hyun‐dong Shin
- School of Chemical and Biomolecular EngineeringGeorgia Institute of TechnologyAtlantaGA30332USA
| | - Guocheng Du
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of EducationJiangnan UniversityWuxi214122China
- Key Laboratory of Industrial Biotechnology, Ministry of EducationJiangnan UniversityWuxi214122China
| | - Jian Chen
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of EducationJiangnan UniversityWuxi214122China
- Key Laboratory of Industrial Biotechnology, Ministry of EducationJiangnan UniversityWuxi214122China
| | - Long Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of EducationJiangnan UniversityWuxi214122China
- Key Laboratory of Industrial Biotechnology, Ministry of EducationJiangnan UniversityWuxi214122China
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28
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Gene modification of Escherichia coli and incorporation of process control to decrease acetate accumulation and increase ʟ-tryptophan production. ANN MICROBIOL 2017. [DOI: 10.1007/s13213-017-1289-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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Gene modification of the acetate biosynthesis pathway in Escherichia coli and implementation of the cell recycling technology to increase L-tryptophan production. PLoS One 2017. [PMID: 28622378 PMCID: PMC5473561 DOI: 10.1371/journal.pone.0179240] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The implementation of a novel cell recycling technology based on a special disk centrifuge during microbial fermentation process can continuously separate the product and harmful intermediates, while maintaining the cell viability owing to the installed cooling system. Acetate accumulation is an often encountered problem in L-tryptophan fermentation by Escherichia coli. To extend our previous studies, the current study deleted the key genes underlying acetate biosynthesis to improve l-tryptophan production. The deletion of the phosphotransacetylase (pta)-acetate kinase (ackA) pathway in a gltB (encoding glutamate synthase) mutant of E. coli TRTHB, led to the highest production of l-tryptophan (47.18 g/L) and glucose conversion rate (17.83%), with a marked reduction in acetate accumulation (1.22 g/L). This strain, TRTHBPA, was then used to investigate the effects of the cell recycling process on L-tryptophan fermentation. Four different strategies were developed concerning two issues, the volume ratio of the concentrated cell solution and clear solution and the cell recycling period. With strategy I (concentrated cell solution: clear solution, 1: 1; cell recycling within 24-30 h), L-tryptophan production and the glucose conversion rate increased to 55.12 g/L and 19.75%, respectively, 17.55% and 10.77% higher than those without the cell recycling. In addition, the biomass increased by 13.52% and the fermentation period was shortened from 40 h to 32 h. These results indicated that the cell recycling technology significantly improved L-tryptophan production by E. coli.
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Sun Y, Guo W, Wang F, Zhan C, Yang Y, Liu X, Bai Z. Transcriptome analysis of Corynebacterium glutamicum in the process of recombinant protein expression in bioreactors. PLoS One 2017; 12:e0174824. [PMID: 28369109 PMCID: PMC5378358 DOI: 10.1371/journal.pone.0174824] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 03/15/2017] [Indexed: 02/07/2023] Open
Abstract
Corynebacterium glutamicum (C. glutamicum) is a favorable host cell for the production of recombinant proteins, such as important enzymes and pharmaceutical proteins, due to its excellent potential advantages. Herein, we sought to systematically explore the influence of recombinant protein expression on the transcription and metabolism of C. glutamicum. Two C. glutamicum strains, the wild-type strain and an engineered strain expressing enhanced green fluorescent protein (EGFP), were cultured in parallel in 5-L bioreactors to study the change in metabolism in the process of EGFP expression. The results revealed that EGFP expression had great effects on the growth and metabolism of C. glutamicum and contributed to metabolism-like anaerobic conditions as follows: glycolysis was enhanced, the TCA cycle was shunted, and Glu, Val, Met, lactate and acetate were accumulated to produce sufficient ATP for EGFP production and transfer. Many differentially expressed genes related to ribosomal protein, transcriptional regulators, and energy metabolism were found to be expressed in the presence of EGFP, laying the foundation for identifying genomic loci to change the flow of the host cell metabolism to improve the ability of expressing foreign proteins in C. glutamicum.
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Affiliation(s)
- Yang Sun
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Wenwen Guo
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Fen Wang
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Chunjun Zhan
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Yankun Yang
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Xiuxia Liu
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Zhonghu Bai
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
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Long CP, Au J, Sandoval NR, Gebreselassie NA, Antoniewicz MR. Enzyme I facilitates reverse flux from pyruvate to phosphoenolpyruvate in Escherichia coli. Nat Commun 2017; 8:14316. [PMID: 28128209 PMCID: PMC5290146 DOI: 10.1038/ncomms14316] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 12/16/2016] [Indexed: 01/29/2023] Open
Abstract
The bacterial phosphoenolpyruvate-carbohydrate phosphotransferase system (PTS) consists of cascading phosphotransferases that couple the simultaneous import and phosphorylation of a variety of sugars to the glycolytic conversion of phosphoenolpyruvate (PEP) to pyruvate. As the primary route of glucose uptake in E. coli, the PTS plays a key role in regulating central carbon metabolism and carbon catabolite repression, and is a frequent target of metabolic engineering interventions. Here we show that Enzyme I, the terminal phosphotransferase responsible for the conversion of PEP to pyruvate, is responsible for a significant in vivo flux in the reverse direction (pyruvate to PEP) during both gluconeogenic and glycolytic growth. We use 13C alanine tracers to quantify this back-flux in single and double knockouts of genes relating to PEP synthetase and PTS components. Our findings are relevant to metabolic engineering design and add to our understanding of gene-reaction connectivity in E. coli.
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Affiliation(s)
- Christopher P. Long
- Department of Chemical and Biomolecular Engineering, Metabolic Engineering and Systems Biology Laboratory, University of Delaware, Newark Delaware 19716, USA
| | - Jennifer Au
- Department of Chemical and Biomolecular Engineering, Metabolic Engineering and Systems Biology Laboratory, University of Delaware, Newark Delaware 19716, USA
| | - Nicholas R. Sandoval
- Department of Chemical and Biomolecular Engineering, Metabolic Engineering and Systems Biology Laboratory, University of Delaware, Newark Delaware 19716, USA
| | - Nikodimos A. Gebreselassie
- Department of Chemical and Biomolecular Engineering, Metabolic Engineering and Systems Biology Laboratory, University of Delaware, Newark Delaware 19716, USA
| | - Maciek R. Antoniewicz
- Department of Chemical and Biomolecular Engineering, Metabolic Engineering and Systems Biology Laboratory, University of Delaware, Newark Delaware 19716, USA
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32
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Bernal V, Castaño-Cerezo S, Cánovas M. Acetate metabolism regulation in Escherichia coli: carbon overflow, pathogenicity, and beyond. Appl Microbiol Biotechnol 2016; 100:8985-9001. [DOI: 10.1007/s00253-016-7832-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 08/22/2016] [Accepted: 08/24/2016] [Indexed: 12/11/2022]
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33
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Chen S, Jia N, Ding MZ, Yuan YJ. Comparative analysis of L-sorbose dehydrogenase by docking strategy for 2-keto-L-gulonic acid production in Ketogulonicigenium vulgare and Bacillus endophyticus consortium. J Ind Microbiol Biotechnol 2016; 43:1507-1516. [PMID: 27565673 DOI: 10.1007/s10295-016-1829-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 07/28/2016] [Indexed: 12/11/2022]
Abstract
Improving the yield of 2-keto-L-gulonic acid (2-KGA), the direct precursor of vitamin C, draws more and more attention in industrial production. In this study, we try to increase the 2-KGA productivity by computer-aided selection of genes encoding L-sorbose dehydrogenases (SDH) of Ketogulonicigenium vulgare. First, six SDHs were modeled by docking strategy to predict the binding mode with co-factor PQQ. The binding energy between SSDA1-H/SSDA1-L and PQQ was the highest, followed by SSDA3/SSDA2. The binding energy between SSDA1-P/SSDB and PQQ was the lowest. Then, these genes were overexpressed, respectively, in an industrial strain K. vulgare HKv604. Overexpression of ssda1-l and ssda1-h enhanced the 2-KGA production by 7.89 and 12.56 % in mono-cultured K. vulgare, and by 13.21 and 16.86 % when K. vulgare was co-cultured with Bacillus endophyticus. When the engineered K. vulgare SyBE_Kv000116013 (overexpression of ssda1-p) or SyBE_Kv000116016 (overexpression of ssdb) was co-cultured with B. endophyticus, the 2-KGA production decreased significantly. The docking results were in accordance with the experimental data, which indicated that computer-aided modeling is an efficient strategy for screening more efficient enzymes.
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Affiliation(s)
- Si Chen
- Key Laboratory of Systems Bioengineering (Ministry of Education) School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, People's Republic of China
| | - Nan Jia
- Key Laboratory of Systems Bioengineering (Ministry of Education) School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, People's Republic of China
| | - Ming-Zhu Ding
- Key Laboratory of Systems Bioengineering (Ministry of Education) School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China. .,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, People's Republic of China.
| | - Ying-Jin Yuan
- Key Laboratory of Systems Bioengineering (Ministry of Education) School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, People's Republic of China
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Liu X, Lin J, Hu H, Zhou B, Zhu B. Site-specific integration and constitutive expression of key genes into Escherichia coli chromosome increases shikimic acid yields. Enzyme Microb Technol 2016; 82:96-104. [DOI: 10.1016/j.enzmictec.2015.08.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 08/30/2015] [Accepted: 08/31/2015] [Indexed: 01/05/2023]
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35
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Liu M, Feng X, Ding Y, Zhao G, Liu H, Xian M. Metabolic engineering of Escherichia coli to improve recombinant protein production. Appl Microbiol Biotechnol 2015; 99:10367-77. [DOI: 10.1007/s00253-015-6955-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 08/18/2015] [Accepted: 08/22/2015] [Indexed: 01/13/2023]
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36
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Metabolic engineering of Escherichia coli using CRISPR–Cas9 meditated genome editing. Metab Eng 2015; 31:13-21. [DOI: 10.1016/j.ymben.2015.06.006] [Citation(s) in RCA: 267] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 06/19/2015] [Accepted: 06/22/2015] [Indexed: 12/17/2022]
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37
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Impact of deletion of the genes encoding acetate kinase on production of L-tryptophan by Escherichia coli. ANN MICROBIOL 2015. [DOI: 10.1007/s13213-015-1103-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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38
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Cheng L, Wang J, Fu Q, Miao L, Yang X, Li S, Li F, Shen Z. Optimization of carbon and nitrogen sources and substrate feeding strategy to increase the cell density ofStreptococcus suis. BIOTECHNOL BIOTEC EQ 2015. [DOI: 10.1080/13102818.2015.1039465] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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39
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Metabolic engineering of Enterobacter cloacae for high-yield production of enantiopure (2 R ,3 R )-2,3-butanediol from lignocellulose-derived sugars. Metab Eng 2015; 28:19-27. [DOI: 10.1016/j.ymben.2014.11.010] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 11/19/2014] [Accepted: 11/26/2014] [Indexed: 01/25/2023]
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40
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Zhang C, Zou R, Chen X, Stephanopoulos G, Too HP. Experimental design-aided systematic pathway optimization of glucose uptake and deoxyxylulose phosphate pathway for improved amorphadiene production. Appl Microbiol Biotechnol 2015; 99:3825-37. [DOI: 10.1007/s00253-015-6463-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 01/29/2015] [Accepted: 02/05/2015] [Indexed: 12/26/2022]
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41
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Wang J, Wen B, Xu Q, Xie X, Chen N. Optimization of carbon source and glucose feeding strategy for improvement of L-isoleucine production by Escherichia coli. BIOTECHNOL BIOTEC EQ 2015; 29:374-380. [PMID: 26019655 PMCID: PMC4433842 DOI: 10.1080/13102818.2015.1006899] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Accepted: 10/24/2014] [Indexed: 11/30/2022] Open
Abstract
Fed-batch cultivations of L-isoleucine-producing Escherichia coli TRFP (SGr, α-ABAr, with a pTHR101 plasmid containing a thr operon and ilvA) were carried out on different carbon sources: glucose, sucrose, fructose, maltose and glycerol. The results indicated that sucrose was the best initial carbon source for L-isoleucine production and then sucrose concentration of 30 g·L−1 was determined in the production medium. The results of different carbon sources feeding showed that the glucose solution was the most suitable feeding media. The dissolved oxygen (DO) of L-isoleucine fermentation was maintained at 5%, 15% and 30% with DO-stat feeding, respectively. The results indicated that when the DO level was maintained at 30%, the highest biomass and L-isoleucine production were obtained. The accumulation of acetate was decreased and the production of L-isoleucine was increased markedly, when the glucose concentration was maintained at 0.15 g·L−1 by using glucose-stat feeding. Finally, the glucose concentration was maintained at 0.10 g·L−1 and the DO level was controlled at approximately 30% during the whole fermentation period, using the combined feeding strategy of glucose-stat feeding and DO feedback feeding. The acetate accumulation was decreased to 7.23 g·L−1, and biomass and production of L-isoleucine were increased to 46.8 and 11.95 g·L−1, respectively.
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Affiliation(s)
- Jian Wang
- Department of Bioengineering, College of Biological and Agricultural Engineering, Jilin University, Changchun , Jilin , China
| | - Bing Wen
- National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology , Tianjin , China ; Key Laboratory of Industrial Microbiology of Education Ministry, Tianjin University of Science and Technology , Tianjin , China ; Tianjin Research Institute of Industrial Microbiology , Tianjin , China
| | - Qingyang Xu
- National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology , Tianjin , China ; Key Laboratory of Industrial Microbiology of Education Ministry, Tianjin University of Science and Technology , Tianjin , China
| | - Xixian Xie
- National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology , Tianjin , China ; Key Laboratory of Industrial Microbiology of Education Ministry, Tianjin University of Science and Technology , Tianjin , China
| | - Ning Chen
- National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology , Tianjin , China ; Key Laboratory of Industrial Microbiology of Education Ministry, Tianjin University of Science and Technology , Tianjin , China
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Vargas-Tah A, Martínez LM, Hernández-Chávez G, Rocha M, Martínez A, Bolívar F, Gosset G. Production of cinnamic and p-hydroxycinnamic acid from sugar mixtures with engineered Escherichia coli. Microb Cell Fact 2015; 14:6. [PMID: 25592545 PMCID: PMC4305220 DOI: 10.1186/s12934-014-0185-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 12/20/2014] [Indexed: 11/15/2022] Open
Abstract
Background The aromatic compounds cinnamic acid (CA) and p-hydroxycinnamic acid (pHCA) are used as flavoring agents as well as precursors of chemicals. These compounds are present in plants at low concentrations, therefore, complex purification processes are usually required to extract the product. An alternative production method for these aromatic acids is based on the use of microbial strains modified by metabolic engineering. These biotechnological processes are usually based on the use of simple sugars like glucose as a raw material. However, sustainable production processes should preferably be based on the use of waste material such as lignocellulosic hydrolysates. Results In this study, E. coli strains with active (W3110) and inactive phosphoenolpyruvate:sugar phosphotransferase system (PTS) (VH33) were engineered for CA and pHCA production by transforming them with plasmids expressing genes encoding phenylalanine/tyrosine ammonia lyase (PAL/TAL) enzymes from Rhodotorula glutinis or Arabidopsis thaliana as well as genes aroGfbr and tktA, encoding a feedback inhibition resistant version of 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase and transketolase, respectively. The generated strains were evaluated in cultures with glucose, xylose or arabinose, as well as a simulated lignocellulosic hydrolysate containing a mixture of these three sugars plus acetate. Production of CA was detected in strains expressing PAL/TAL from A. thaliana, whereas both CA and pHCA accumulated in strains expressing the enzyme from R. glutinis. These experiments identified arabinose and W3110 expressing PAL/TAL from A. thaliana, aroGfbr and tktA as the carbon source/strain combination resulting in the best CA specific productivity and titer. To improve pHCA production, a mutant with inactive pheA gene was generated, causing an 8-fold increase in the yield of this aromatic acid from the sugars in a simulated hydrolysate. Conclusions In this study the quantitative contribution of active or inactive PTS as well as expression of PAL/TAL from R. glutinis or A. thaliana were determined for production performance of CA and pHCA when growing on carbon sources derived from lignocellulosic hydrolysates. These data will be a useful resource in efforts towards the development of sustainable technologies for the production of aromatic acids. Electronic supplementary material The online version of this article (doi:10.1186/s12934-014-0185-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Alejandra Vargas-Tah
- Departamento de Ingeniería Celular y Biocatálisis, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca, Morelos, 62210, México.
| | - Luz María Martínez
- Departamento de Ingeniería Celular y Biocatálisis, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca, Morelos, 62210, México.
| | - Georgina Hernández-Chávez
- Departamento de Ingeniería Celular y Biocatálisis, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca, Morelos, 62210, México.
| | - Mario Rocha
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca, Morelos, 62210, México.
| | - Alfredo Martínez
- Departamento de Ingeniería Celular y Biocatálisis, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca, Morelos, 62210, México.
| | - Francisco Bolívar
- Departamento de Ingeniería Celular y Biocatálisis, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca, Morelos, 62210, México.
| | - Guillermo Gosset
- Departamento de Ingeniería Celular y Biocatálisis, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca, Morelos, 62210, México.
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Brockman IM, Prather KLJ. Dynamic knockdown of E. coli central metabolism for redirecting fluxes of primary metabolites. Metab Eng 2014; 28:104-113. [PMID: 25542851 DOI: 10.1016/j.ymben.2014.12.005] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 12/12/2014] [Accepted: 12/16/2014] [Indexed: 11/17/2022]
Abstract
Control of native enzyme levels is important when optimizing strains for overproduction of heterologous compounds. However, for many central metabolic enzymes, static knockdown results in poor growth and protein expression. We have developed a strategy for dynamically modulating the abundance of native enzymes within the host cell and applied this to a model system for myo-inositol production from glucose. This system relies on controlled degradation of a key glycolytic enzyme, phosphofructokinase-I (Pfk-I). Through tuning Pfk-I levels, we have been able to develop an Escherichia coli strain with a growth mode close to wild type and a production mode with an increased glucose-6-phosphate pool available for conversion into myo-inositol. The switch to production mode is trigged by inducer addition, allowing yield, titer, and productivity to be managed through induction time. By varying the time of Pfk-I degradation, we were able to achieve a two-fold improvement in yield and titers of myo-inositol.
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Affiliation(s)
- Irene M Brockman
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Kristala L J Prather
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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44
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Mahalik S, Sharma AK, Mukherjee KJ. Genome engineering for improved recombinant protein expression in Escherichia coli. Microb Cell Fact 2014; 13:177. [PMID: 25523647 PMCID: PMC4300154 DOI: 10.1186/s12934-014-0177-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 12/05/2014] [Indexed: 01/09/2023] Open
Abstract
A metabolic engineering perspective which views recombinant protein
expression as a multistep pathway allows us to move beyond vector design and
identify the downstream rate limiting steps in expression. In E.coli these are typically at the translational level
and the supply of precursors in the form of energy, amino acids and nucleotides.
Further recombinant protein production triggers a global cellular stress response
which feedback inhibits both growth and product formation. Countering this requires
a system level analysis followed by a rational host cell engineering to sustain
expression for longer time periods. Another strategy to increase protein yields
could be to divert the metabolic flux away from biomass formation and towards
recombinant protein production. This would require a growth stoppage mechanism which
does not affect the metabolic activity of the cell or the transcriptional or
translational efficiencies. Finally cells have to be designed for efficient export
to prevent buildup of proteins inside the cytoplasm and also simplify downstream
processing. The rational and the high throughput strategies that can be used for the
construction of such improved host cell platforms for recombinant protein expression
is the focus of this review.
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Affiliation(s)
- Shubhashree Mahalik
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India.
| | - Ashish K Sharma
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India.
| | - Krishna J Mukherjee
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India.
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Morshedi D, Aliakbari F, Nouri HR, Lotfinia M, Fallahi J. Using small molecules as a new challenge to redirect metabolic pathway. 3 Biotech 2014; 4:513-522. [PMID: 28324386 PMCID: PMC4162896 DOI: 10.1007/s13205-013-0185-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 11/09/2013] [Indexed: 11/26/2022] Open
Abstract
The presence of acetate in the bacterial medium leads to a reduction in the growth rate of cells and recombinant protein production. In this study, three compounds including propionic acid, lithium chloride and butyric acid were added to the medium which decreased acetate levels and enhanced recombinant protein production (alpha-synuclein). In fact, propionic acid and lithium chloride are both known as acetate kinase inhibitors. The results obtained in the case of butyric acid were similar to those of the two other compounds indicating that butyric acid may act through a mechanism similar to propionic acid and lithium chloride. Consequently, it was shown that the presence of each of these supplements (5–200 μM) increased recombinant alpha-synuclein production and cell density by approximately 10–15 %. HPLC analysis showed that the levels of acetate in the media containing the supplements were considerably less than those of the control. Furthermore, pH values remained almost constant in the supplemented cultures. Growing the bacteria at lower temperatures (25 °C) indicated that the positive effects of these supplements were not as effective as at higher temperatures (37 °C), presumably due to the adequate balance between oxygen and carbon consumption. This study can confirm the viewpoint regarding the harmful effects of acetate on the recombinant protein production and cell density. Besides, such methods represent easy and complementary ways to increase target recombinant protein production without negatively affecting host cell density, and requiring complex genetic manipulation.
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Affiliation(s)
- Dina Morshedi
- Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Shahrak-e Pajoohesh, km 15, Tehran-Karaj Highway, P. O. Box: 14965/161, Tehran, Iran.
| | - Farhang Aliakbari
- Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Shahrak-e Pajoohesh, km 15, Tehran-Karaj Highway, P. O. Box: 14965/161, Tehran, Iran
- Department of Biotechnology, Semnan University of Medical Sciences, Semnan, Iran
| | - Hamid Reza Nouri
- Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Shahrak-e Pajoohesh, km 15, Tehran-Karaj Highway, P. O. Box: 14965/161, Tehran, Iran
| | - Majid Lotfinia
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
- Department of Biochemistry, Pasteur Institute of Iran, Tehran, Iran
| | - Jafar Fallahi
- Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Shahrak-e Pajoohesh, km 15, Tehran-Karaj Highway, P. O. Box: 14965/161, Tehran, Iran
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46
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The transport and mediation mechanisms of the common sugars in Escherichia coli. Biotechnol Adv 2014; 32:905-19. [DOI: 10.1016/j.biotechadv.2014.04.009] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 03/23/2014] [Accepted: 04/18/2014] [Indexed: 11/17/2022]
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Pablos TE, Sigala JC, Le Borgne S, Lara AR. Aerobic expression ofVitreoscillahemoglobin efficiently reduces overflow metabolism inEscherichia coli. Biotechnol J 2014; 9:791-9. [DOI: 10.1002/biot.201300388] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 01/25/2014] [Accepted: 02/17/2014] [Indexed: 12/17/2022]
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Effect of growth rate on plasmid DNA production and metabolic performance of engineered Escherichia coli strains. J Biosci Bioeng 2014; 117:336-42. [DOI: 10.1016/j.jbiosc.2013.08.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 08/01/2013] [Accepted: 08/13/2013] [Indexed: 12/15/2022]
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Abstract
Recent developments in DNA vaccine research provide a new momentum for this rather young and potentially disruptive technology. Gene-based vaccines are capable of eliciting protective immunity in humans to persistent intracellular pathogens, such as HIV, malaria, and tuberculosis, for which the conventional vaccine technologies have failed so far. The recent identification and characterization of genes coding for tumor antigens has stimulated the development of DNA-based antigen-specific cancer vaccines. Although most academic researchers consider the production of reasonable amounts of plasmid DNA (pDNA) for immunological studies relatively easy to solve, problems often arise during this first phase of production. In this chapter we review the current state of the art of pDNA production at small (shake flasks) and mid-scales (lab-scale bioreactor fermentations) and address new trends in vector design and strain engineering. We will guide the reader through the different stages of process design starting from choosing the most appropriate plasmid backbone, choosing the right Escherichia coli (E. coli) strain for production, and cultivation media and scale-up issues. In addition, we will address some points concerning the safety and potency of the produced plasmids, with special focus on producing antibiotic resistance-free plasmids. The main goal of this chapter is to make immunologists aware of the fact that production of the pDNA vaccine has to be performed with as much as attention and care as the rest of their research.
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Licona-Cassani C, Lara AR, Cabrera-Valladares N, Escalante A, Hernández-Chávez G, Martinez A, Bolívar F, Gosset G. Inactivation of Pyruvate Kinase or the Phosphoenolpyruvate: Sugar Phosphotransferase System Increases Shikimic and Dehydroshikimic Acid Yields from Glucose inBacillus subtilis. J Mol Microbiol Biotechnol 2014; 24:37-45. [DOI: 10.1159/000355264] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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