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Disrupting the ArcA Regulatory Network Amplifies the Fitness Cost of Tetracycline Resistance in Escherichia coli. mSystems 2023; 8:e0090422. [PMID: 36537814 PMCID: PMC9948699 DOI: 10.1128/msystems.00904-22] [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] [Indexed: 02/24/2023] Open
Abstract
There is an urgent need for strategies to discover secondary drugs to prevent or disrupt antimicrobial resistance (AMR), which is causing >700,000 deaths annually. Here, we demonstrate that tetracycline-resistant (TetR) Escherichia coli undergoes global transcriptional and metabolic remodeling, including downregulation of tricarboxylic acid cycle and disruption of redox homeostasis, to support consumption of the proton motive force for tetracycline efflux. Using a pooled genome-wide library of single-gene deletion strains, at least 308 genes, including four transcriptional regulators identified by our network analysis, were confirmed as essential for restoring the fitness of TetR E. coli during treatment with tetracycline. Targeted knockout of ArcA, identified by network analysis as a master regulator of this new compensatory physiological state, significantly compromised fitness of TetR E. coli during tetracycline treatment. A drug, sertraline, which generated a similar metabolome profile as the arcA knockout strain, also resensitized TetR E. coli to tetracycline. We discovered that the potentiating effect of sertraline was eliminated upon knocking out arcA, demonstrating that the mechanism of potential synergy was through action of sertraline on the tetracycline-induced ArcA network in the TetR strain. Our findings demonstrate that therapies that target mechanistic drivers of compensatory physiological states could resensitize AMR pathogens to lost antibiotics. IMPORTANCE Antimicrobial resistance (AMR) is projected to be the cause of >10 million deaths annually by 2050. While efforts to find new potent antibiotics are effective, they are expensive and outpaced by the rate at which new resistant strains emerge. There is desperate need for a rational approach to accelerate the discovery of drugs and drug combinations that effectively clear AMR pathogens and even prevent the emergence of new resistant strains. Using tetracycline-resistant (TetR) Escherichia coli, we demonstrate that gaining resistance is accompanied by loss of fitness, which is restored by compensatory physiological changes. We demonstrate that transcriptional regulators of the compensatory physiologic state are promising drug targets because their disruption increases the susceptibility of TetR E. coli to tetracycline. Thus, we describe a generalizable systems biology approach to identify new vulnerabilities within AMR strains to rationally accelerate the discovery of therapeutics that extend the life span of existing antibiotics.
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2
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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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3
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Mahalik S, Sharma A, Das DR, Mittra D, Mukherjee KJ. Co-expressing Leucine Responsive Regulatory protein (Lrp) enhances Recombinant L-Asparaginase-II production in Escherichia coli. J Biotechnol 2022; 351:99-108. [DOI: 10.1016/j.jbiotec.2022.04.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 04/25/2022] [Accepted: 04/26/2022] [Indexed: 11/27/2022]
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4
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Matson MM, Cepeda MM, Zhang A, Case AE, Kavvas ES, Wang X, Carroll AL, Tagkopoulos I, Atsumi S. Adaptive laboratory evolution for improved tolerance of isobutyl acetate in Escherichia coli. Metab Eng 2021; 69:50-58. [PMID: 34763090 DOI: 10.1016/j.ymben.2021.11.002] [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: 08/14/2021] [Revised: 10/14/2021] [Accepted: 11/04/2021] [Indexed: 02/08/2023]
Abstract
Previously, Escherichia coli was engineered to produce isobutyl acetate (IBA). Titers greater than the toxicity threshold (3 g/L) were achieved by using layer-assisted production. To avoid this costly and complex method, adaptive laboratory evolution (ALE) was applied to E. coli for improved IBA tolerance. Over 37 rounds of selective pressure, 22 IBA-tolerant mutants were isolated. Remarkably, these mutants not only tolerate high IBA concentrations, they also produce higher IBA titers. Using whole-genome sequencing followed by CRISPR/Cas9 mediated genome editing, the mutations (SNPs in metH, rho and deletion of arcA) that confer improved tolerance and higher titers were elucidated. The improved IBA titers in the evolved mutants were a result of an increased supply of acetyl-CoA and altered transcriptional machinery. Without the use of phase separation, a strain capable of 3.2-fold greater IBA production than the parent strain was constructed by combing select beneficial mutations. These results highlight the impact improved tolerance has on the production capability of a biosynthetic system.
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Affiliation(s)
- Morgan M Matson
- Department of Chemistry, University of California, Davis, CA, 95616, USA
| | - Mateo M Cepeda
- Department of Chemistry, University of California, Davis, CA, 95616, USA
| | - Angela Zhang
- Department of Chemistry, University of California, Davis, CA, 95616, USA
| | - Anna E Case
- Department of Chemistry, University of California, Davis, CA, 95616, USA
| | - Erol S Kavvas
- Genome Center, University of California, Davis, CA, 95616, USA
| | - Xiaokang Wang
- Genome Center, University of California, Davis, CA, 95616, USA; Department of Biomedical Engineering, University of California, Davis, CA 95616, USA
| | - Austin L Carroll
- Department of Chemistry, University of California, Davis, CA, 95616, USA
| | - Ilias Tagkopoulos
- Genome Center, University of California, Davis, CA, 95616, USA; Department of Computer Science, University of California, Davis, CA, 95616, USA
| | - Shota Atsumi
- Department of Chemistry, University of California, Davis, CA, 95616, USA.
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5
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Hoke KL, Zimmer SL, Roddy AB, Ondrechen MJ, Williamson CE, Buan NR. Reintegrating Biology Through the Nexus of Energy, Information, and Matter. Integr Comp Biol 2021; 61:2082-2094. [PMID: 34374780 DOI: 10.1093/icb/icab174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Information, energy, and matter are fundamental properties of all levels of biological organization, and life emerges from the continuous flux of matter, energy, and information. This perspective piece defines and explains each of the three pillars of this nexus. We propose that a quantitative characterization of the complex interconversions between matter, energy, and information that comprise this nexus will help us derive biological insights that connect phenomena across different levels of biological organization. We articulate examples from multiple biological scales that highlight how this nexus approach leads to a more complete understanding of the biological system. Metrics of energy, information, and matter can provide a common currency that helps link phenomena across levels of biological organization. The propagation of energy and information through levels of biological organization can result in emergent properties and system-wide changes that impact other hierarchical levels. Deeper consideration of measured imbalances in energy, information, and matter can help researchers identify key factors that influence system function at one scale, highlighting avenues to link phenomena across levels of biological organization and develop predictive models of biological systems.
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Affiliation(s)
- Kim L Hoke
- Department of Biology, Colorado State University, Fort Collins, CO 80523-1878
| | - Sara L Zimmer
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth campus, Duluth, MN 55812
| | - Adam B Roddy
- Institute of Environment, Department of Biological Sciences, Florida International University, Miami, FL 33199
| | - Mary Jo Ondrechen
- Department of Chemistry & Chemical Biology, Northeastern University, Boston, MA 02115
| | | | - Nicole R Buan
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0662
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6
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Liao Y, Ni Z, Wu J, Li Z, Ge Y, Chen X, Yao J. Effect of acetate metabolism modulation on 2'-fucosyllactose production in engineered Escherichia coli. BIOTECHNOL BIOTEC EQ 2021. [DOI: 10.1080/13102818.2021.1885996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Affiliation(s)
- Yingxue Liao
- Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, PR China
- Scinece Island Branch, Graduate School of USTC, Hefei, PR China
| | - Zhijian Ni
- Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, PR China
- Scinece Island Branch, Graduate School of USTC, Hefei, PR China
| | - Jinyong Wu
- Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, PR China
- Huainan New Energy Research Center, Institute of Plasma Physics, Chinese Academy of Sciences, Huainan, Anhui, PR China
| | - Zhongkui Li
- Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, PR China
- Scinece Island Branch, Graduate School of USTC, Hefei, PR China
| | - Yuanfei Ge
- Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, PR China
- Scinece Island Branch, Graduate School of USTC, Hefei, PR China
| | - Xiangsong Chen
- Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, PR China
- Huainan New Energy Research Center, Institute of Plasma Physics, Chinese Academy of Sciences, Huainan, Anhui, PR China
| | - Jianming Yao
- Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, PR China
- Scinece Island Branch, Graduate School of USTC, Hefei, PR China
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7
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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: 10] [Impact Index Per Article: 2.5] [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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8
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Guleria R, Jain P, Verma M, Mukherjee KJ. Designing next generation recombinant protein expression platforms by modulating the cellular stress response in Escherichia coli. Microb Cell Fact 2020; 19:227. [PMID: 33308214 PMCID: PMC7730785 DOI: 10.1186/s12934-020-01488-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 11/28/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A cellular stress response (CSR) is triggered upon recombinant protein synthesis which acts as a global feedback regulator of protein expression. To remove this key regulatory bottleneck, we had previously proposed that genes that are up-regulated post induction could be part of the signaling pathways which activate the CSR. Knocking out some of these genes which were non-essential and belonged to the bottom of the E. coli regulatory network had provided higher expression of GFP and L-asparaginase. RESULTS We chose the best performing double knockout E. coli BW25113ΔelaAΔcysW and demonstrated its ability to enhance the expression of the toxic Rubella E1 glycoprotein by 2.5-fold by tagging it with sfGFP at the C-terminal end to better quantify expression levels. Transcriptomic analysis of this hyper-expressing mutant showed that a significantly lower proportion of genes got down-regulated post induction, which included genes for transcription, translation, protein folding and sorting, ribosome biogenesis, carbon metabolism, amino acid and ATP synthesis. This down-regulation which is a typical feature of the CSR was clearly blocked in the double knockout strain leading to its enhanced expression capability. Finally, we supplemented the expression of substrate uptake genes glpK and glpD whose down-regulation was not prevented in the double knockout, thus ameliorating almost all the negative effects of the CSR and obtained a further doubling in recombinant protein yields. CONCLUSION The study validated the hypothesis that these up-regulated genes act as signaling messengers which activate the CSR and thus, despite having no casual connection with recombinant protein synthesis, can improve cellular health and protein expression capabilities. Combining gene knockouts with supplementing the expression of key down-regulated genes can counter the harmful effects of CSR and help in the design of a truly superior host platform for recombinant protein expression.
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Affiliation(s)
- Richa Guleria
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Priyanka Jain
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Madhulika Verma
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Krishna J Mukherjee
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India. .,Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, 110016, India.
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9
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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: 8] [Impact Index Per Article: 2.0] [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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10
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Kalnenieks U, Balodite E, Rutkis R. Metabolic Engineering of Bacterial Respiration: High vs. Low P/O and the Case of Zymomonas mobilis. Front Bioeng Biotechnol 2019; 7:327. [PMID: 31781557 PMCID: PMC6861446 DOI: 10.3389/fbioe.2019.00327] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 10/28/2019] [Indexed: 11/13/2022] Open
Abstract
Respiratory chain plays a pivotal role in the energy and redox balance of aerobic bacteria. By engineering respiration, it is possible to alter the efficiency of energy generation and intracellular redox state, and thus affect the key bioprocess parameters: cell yield, productivity and stress resistance. Here we summarize the current metabolic engineering and synthetic biology approaches to bacterial respiratory metabolism, with a special focus on the respiratory chain of the ethanologenic bacterium Zymomonas mobilis. Electron transport in Z. mobilis can serve as a model system of bacterial respiration with low oxidative phosphorylation efficiency. Its application for redox balancing and relevance for improvement of stress tolerance are analyzed.
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Affiliation(s)
- Uldis Kalnenieks
- Institute of Microbiology and Biotechnology, University of Latvia, Riga, Latvia
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11
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Pooth V, van Gaalen K, Trenkamp S, Wiechert W, Oldiges M. Comprehensive analysis of metabolic sensitivity of 1,4-butanediol producing Escherichia coli toward substrate and oxygen availability. Biotechnol Prog 2019; 36:e2917. [PMID: 31587523 DOI: 10.1002/btpr.2917] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 08/12/2019] [Accepted: 08/28/2019] [Indexed: 12/14/2022]
Abstract
Nowadays, chemical production of 1,4-butanediol is supplemented by biotechnological processes using a genetically modified Escherichia coli strain, which is an industrial showcase of successful application of metabolic engineering. However, large scale bioprocess performance can be affected by presence of physical and chemical gradients in bioreactors which are a consequence of imperfect mixing and limited oxygen transfer. Hence, upscaling comes along with local and time dependent fluctuations of cultivation conditions. This study emphasizes on scale-up related effects of microbial 1,4-butanediol production by comprehensive bioprocess characterization in lab scale. Due to metabolic network constraints 1,4-butanediol formation takes place under oxygen limited microaerobic conditions, which can be hardly realized in large scale bioreactor. The purpose of this study was to assess the extent to which substrate and oxygen availability influence the productivity. It was found, that the substrate specific product yield and the production rate are higher under substrate excess than under substrate limitation. Furthermore, the level of oxygen supply within microaerobic conditions revealed strong effects on product and by-product formation. Under strong oxygen deprivation nearly 30% of the consumed carbon is converted into 1,4-butanediol, whereas an increase in oxygen supply results in 1,4-butanediol reduction of 77%. Strikingly, increasing oxygen availability leads to strong increase of main by-product acetate as well as doubled carbon dioxide formation. The study provides clear evidence that scale-up of microaerobic bioprocesses constitute a substantial challenge. Although oxygen is strictly required for product formation, the data give clear evidence that terms of anaerobic and especially aerobic conditions strongly interfere with 1,4-butanediol production.
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Affiliation(s)
- Viola Pooth
- Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences, IBG-1: Biotechnology, Jülich, Germany.,RWTH Aachen University, Institute of Biotechnology, Aachen, Germany
| | - Kathrin van Gaalen
- Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences, IBG-1: Biotechnology, Jülich, Germany
| | | | - Wolfgang Wiechert
- Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences, IBG-1: Biotechnology, Jülich, Germany.,RWTH Aachen University, Computational Systems Biotechnology (AVT.CSB), Aachen, Germany
| | - Marco Oldiges
- Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences, IBG-1: Biotechnology, Jülich, Germany.,RWTH Aachen University, Institute of Biotechnology, Aachen, Germany
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12
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Lara AR, Jaén KE, Folarin O, Keshavarz-Moore E, Büchs J. Effect of the oxygen transfer rate on oxygen-limited production of plasmid DNA by Escherichia coli. Biochem Eng J 2019. [DOI: 10.1016/j.bej.2019.107303] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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13
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Han Q, Eiteman MA. Acetate formation during recombinant protein production in Escherichia coli K-12 with an elevated NAD(H) pool. Eng Life Sci 2019; 19:770-780. [PMID: 32624970 DOI: 10.1002/elsc.201900045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 08/15/2019] [Accepted: 08/21/2019] [Indexed: 12/14/2022] Open
Abstract
Acetate formation is a disadvantage in the use of Escherichia coli for recombinant protein production, and many studies have focused on optimizing fermentation processes or altering metabolism to eliminate acetate accumulation. In this study, E. coli MEC697 (MG1655 nadR nudC mazG) maintained a larger pool of NAD(H) compared to the wild-type control, and also accumulated lower concentrations of acetate when grown in batch culture on glucose. In steady-state cultures, the elevated total NAD(H) found in MEC697 delayed the threshold dilution rate for acetate formation to a growth rate of 0.27 h-1. Batch and fed-batch processes using MEC697 were examined for the production of β-galactosidase as a model recombinant protein. Fed-batch culture of MEC697/pTrc99A-lacZ compared to MG1655/pTrc99A-lacZ at a growth rate of 0.22 h-1 showed only a modest increase of protein formation. However, 1 L batch growth of MEC697/pTrc99A-lacZ resulted in 50% lower acetate formation compared to MG1655/pTrc99A-lacZ and a two-fold increase in recombinant protein production.
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Affiliation(s)
- Qi Han
- School of Chemical Materials and Biomedical Engineering University of Georgia Athens GA USA
| | - Mark A Eiteman
- School of Chemical Materials and Biomedical Engineering University of Georgia Athens GA USA
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14
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Ding Z, Fang Y, Zhu L, Wang J, Wang X. Deletion of arcA, iclR, and tdcC in Escherichia coli to improve l-threonine production. Biotechnol Appl Biochem 2019; 66:794-807. [PMID: 31177569 DOI: 10.1002/bab.1789] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 06/06/2019] [Indexed: 11/06/2022]
Abstract
l-Threonine is an important amino acid supplemented in food, medicine, or feed. Starting from glucose, l-threonine production in Escherichia coli involves the glycolysis, TCA cycle, and the l-threonine biosynthetic pathway. In this study, how the l-threonine production in an l-threonine producing E. coli TWF001 is controlled by the three regulators ArcA, Cra, and IclR, which control the expression of genes involved in the glycolysis and TCA cycle, has been investigated. Ten mutant strains were constructed from TWF001 by different combinations of deletion or overexpression of arcA, cra, iclR, and tdcC. l-Threonine production was increased in the mutants TWF015 (ΔarcAΔcra), TWF016 (ΔarcAPcra::Ptrc), TWF017 (ΔarcAΔiclR), TWF018 (ΔarcAΔiclRΔtdcC), and TWF019 (ΔarcAΔcraΔiclRΔtdcC). Among these mutant strains, the highest l-threonine production (26.0 g/L) was obtained in TWF018, which was a 109.7% increase compared with the control TWF001. In addition, TWF018 could consume glucose more efficiently than TWF001 and produce less acetate. The results suggest that deletion of arcA, iclR, and tdcC could efficiently increase l-threonine production in E. coli.
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Affiliation(s)
- Zhixiang Ding
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, People's Republic of China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, People's Republic of China
| | - Yu Fang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, People's Republic of China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, People's Republic of China
| | - Lifei Zhu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, People's Republic of China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, People's Republic of China
| | - Jianli Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, People's Republic of China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, People's Republic of China
| | - Xiaoyuan Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, People's Republic of China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, People's Republic of China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, People's Republic of China
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15
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Tan Z, Zhu C, Fu J, Zhang X, Li M, Zhuang W, Ying H. Regulating Cofactor Balance In Vivo with a Synthetic Flavin Analogue. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201810881] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Zhuotao Tan
- College of Biotechnology and Pharmaceutical Engineering; Nanjing Tech University; 30 S Puzhu Rd 211816 Nanjing China
| | - Chenjie Zhu
- College of Biotechnology and Pharmaceutical Engineering; Nanjing Tech University; 30 S Puzhu Rd 211816 Nanjing China
| | - Jingwen Fu
- College of Biotechnology and Pharmaceutical Engineering; Nanjing Tech University; 30 S Puzhu Rd 211816 Nanjing China
| | - Xiaowang Zhang
- College of Biotechnology and Pharmaceutical Engineering; Nanjing Tech University; 30 S Puzhu Rd 211816 Nanjing China
| | - Ming Li
- College of Biotechnology and Pharmaceutical Engineering; Nanjing Tech University; 30 S Puzhu Rd 211816 Nanjing China
| | - Wei Zhuang
- College of Biotechnology and Pharmaceutical Engineering; Nanjing Tech University; 30 S Puzhu Rd 211816 Nanjing China
| | - Hanjie Ying
- College of Biotechnology and Pharmaceutical Engineering; Nanjing Tech University; 30 S Puzhu Rd 211816 Nanjing China
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Tan Z, Zhu C, Fu J, Zhang X, Li M, Zhuang W, Ying H. Regulating Cofactor Balance In Vivo with a Synthetic Flavin Analogue. Angew Chem Int Ed Engl 2018; 57:16464-16468. [PMID: 30341805 DOI: 10.1002/anie.201810881] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Indexed: 11/07/2022]
Abstract
A novel strategy to regulate cofactor balance in vivo for whole-cell biotransformation using a synthetic flavin analogue is reported. High efficiency, easy operation, and good applicability were observed for this system. Confocal laser scanning microscopy was employed to verify that the synthetic flavin analogue can directly permeate into Escherichia coli cells without modifying the cell membrane. This work provides a promising intracellular redox regulatory approach to construct more efficient cell factories.
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Affiliation(s)
- Zhuotao Tan
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, 30 S Puzhu Rd, 211816, Nanjing, China
| | - Chenjie Zhu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, 30 S Puzhu Rd, 211816, Nanjing, China
| | - Jingwen Fu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, 30 S Puzhu Rd, 211816, Nanjing, China
| | - Xiaowang Zhang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, 30 S Puzhu Rd, 211816, Nanjing, China
| | - Ming Li
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, 30 S Puzhu Rd, 211816, Nanjing, China
| | - Wei Zhuang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, 30 S Puzhu Rd, 211816, Nanjing, China
| | - Hanjie Ying
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, 30 S Puzhu Rd, 211816, Nanjing, China
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Hartmann SK, Stockdreher Y, Wandrey G, Hosseinpour Tehrani H, Zambanini T, Meyer AJ, Büchs J, Blank LM, Schwarzländer M, Wierckx N. Online in vivo monitoring of cytosolic NAD redox dynamics in Ustilago maydis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:1015-1024. [DOI: 10.1016/j.bbabio.2018.05.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 04/06/2018] [Accepted: 05/20/2018] [Indexed: 12/20/2022]
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18
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Han Q, Eiteman MA. Enhancement of NAD(H) pool for formation of oxidized biochemicals in Escherichia coli. J Ind Microbiol Biotechnol 2018; 45:939-950. [PMID: 30159648 DOI: 10.1007/s10295-018-2072-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 08/13/2018] [Indexed: 10/28/2022]
Abstract
The NAD+/NADH ratio and the total NAD(H) play important roles for whole-cell biochemical redox transformations. After the carbon source is exhausted, the degradation of NAD(H) could contribute to a decline in the rate of a desired conversion. In this study, methods to slow the native rate of NAD(H) degradation were examined using whole-cell Escherichia coli with two model oxidative NAD+-dependent biotransformations. A high phosphate concentration (50 mM) was observed to slow NAD(H) degradation. We also constructed E. coli strains with deletions in genes coding several enzymes involved in NAD+ degradation. In shake-flask experiments, the total NAD(H) concentration positively correlated with conversion of xylitol to L-xylulose by xylitol 4-dehydrogenase, and the greatest conversion (80%) was observed using MG1655 nadR nudC mazG/pZE12-xdh/pCS27-nox. Controlled 1-L batch processes comparing E. coli nadR nudC mazG with a wild-type background strain demonstrated a 30% increase in final L-xylulose concentration (5.6 vs. 7.9 g/L) and a 25% increase in conversion (0.53 vs. 0.66 g/g). MG1655 nadR nudC mazG was also examined for the conversion of galactitol to L-tagatose by galactitol 2-dehydrogenase. A batch process using 15 g/L glycerol and 10 g/L galactitol generated over 9.4 g/L L-tagatose, corresponding to 90% conversion and a yield of 0.95 g L-tagatose/g galactitol consumed. The results demonstrate the value of minimizing NAD(H) degradation as a means to improve NAD+-dependent biotransformations.
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Affiliation(s)
- Qi Han
- School of Chemical Materials and Biomedical Engineering, University of Georgia, Athens, GA, 30602, USA
| | - Mark A Eiteman
- School of Chemical Materials and Biomedical Engineering, University of Georgia, Athens, GA, 30602, USA.
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Pinu FR, Granucci N, Daniell J, Han TL, Carneiro S, Rocha I, Nielsen J, Villas-Boas SG. Metabolite secretion in microorganisms: the theory of metabolic overflow put to the test. Metabolomics 2018; 14:43. [PMID: 30830324 DOI: 10.1007/s11306-018-1339-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 02/07/2018] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Microbial cells secrete many metabolites during growth, including important intermediates of the central carbon metabolism. This has not been taken into account by researchers when modeling microbial metabolism for metabolic engineering and systems biology studies. MATERIALS AND METHODS The uptake of metabolites by microorganisms is well studied, but our knowledge of how and why they secrete different intracellular compounds is poor. The secretion of metabolites by microbial cells has traditionally been regarded as a consequence of intracellular metabolic overflow. CONCLUSIONS Here, we provide evidence based on time-series metabolomics data that microbial cells eliminate some metabolites in response to environmental cues, independent of metabolic overflow. Moreover, we review the different mechanisms of metabolite secretion and explore how this knowledge can benefit metabolic modeling and engineering.
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Affiliation(s)
- Farhana R Pinu
- The New Zealand Institute for Plant and Food Research Limited, Private Bag 92169, Auckland, 1142, New Zealand.
| | - Ninna Granucci
- School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - James Daniell
- School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
- LanzaTech, Skokie, IL, 60077, USA
| | - Ting-Li Han
- School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Sonia Carneiro
- Center of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Isabel Rocha
- Center of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Jens Nielsen
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivagen 10, 412 96, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2970, Hørsholm, Denmark
| | - Silas G Villas-Boas
- School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
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20
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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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21
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Han Q, Eiteman MA. Coupling xylitol dehydrogenase with NADH oxidase improves l-xylulose production in Escherichia coli culture. Enzyme Microb Technol 2017; 106:106-113. [PMID: 28859803 DOI: 10.1016/j.enzmictec.2017.07.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 07/06/2017] [Accepted: 07/21/2017] [Indexed: 11/30/2022]
Abstract
Escherichia coli expressing NAD-dependent xylitol-4-dehydrogenase (XDH) from Pantoea ananatis and growing on glucose or glycerol converts xylitol to the rare sugar l-xylulose. Although blocking potential l-xylulose consumption (l-xylulosekinase, lyxK) or co-expression of the glycerol facilitator (glpF) did not significantly affect l-xylulose formation, co-expressing XDH with water-forming NADH oxidase (NOX) from Streptococcus pneumoniae increased l-xylulose formation in shake flasks when glycerol was the carbon source. Controlled batch processes at the 1L scale demonstrated that the final equilibrium l-xylulose/xylitol ratio was correlated to the intracellular NAD+/NADH ratio, with 69% conversion of xylitol to l-xylulose and a yield of 0.88g l-xylulose/g xylitol consumed attained for MG1655/pZE12-xdh/pCS27-nox growing on glycerol. NADH oxidase was less effective at improving l-xylulose formation in the bioreactor than in shake flasks, likely as a result of an intrinsic maximum NAD+/NADH and l-xylulose/xylitol equilibrium ratio being attained. Intermittently feeding carbon source was ineffective at increasing the final l-xylulose concentration because introduction of carbon source was accompanied by a reduction in NAD+/NADH ratio. A batch process using 12g/L glycerol and 22g/L xylitol generated over 14g/L l-xylulose after 80h, corresponding to 65% conversion and a yield of 0.89g l-xylulose/g xylitol consumed.
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Affiliation(s)
- Qi Han
- School of Chemical, Materials and Biomedical Engineering University of Georgia, Athens, GA, 30602, USA
| | - Mark A Eiteman
- School of Chemical, Materials and Biomedical Engineering University of Georgia, Athens, GA, 30602, USA.
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22
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Jayachandran C, Palanisamy Athiyaman B, Sankaranarayanan M. Cofactor engineering improved CALB production in Pichia pastoris through heterologous expression of NADH oxidase and adenylate kinase. PLoS One 2017; 12:e0181370. [PMID: 28715469 PMCID: PMC5513558 DOI: 10.1371/journal.pone.0181370] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 06/29/2017] [Indexed: 12/26/2022] Open
Abstract
The cofactor engineering strategy can relieve the metabolic stress induced by expression of recombinant protein in cellular metabolism related to cofactor and energy reactions. To study the effect of cofactor regeneration on recombinant protein expression, NADH oxidase (noxE) was engineered in P. pastoris expressing lipase B (GSCALB). Expression of noxE in P. pastoris (GSCALBNOX) increased NAD+ levels by 85% with a concomitant reduction in NADH/NAD+ ratio of 67% compared to GSCALB. The change in the redox level positively influenced the methanol uptake rate and made 34% augment in CALB activity. The decline in NADH level (44%) by noxE expression had lowered the adenylate energy charge (AEC) and ATP level in GSCALBNOX. In order to regenerate ATP in GSCALBNOX, adenylate kinase (ADK1) gene from S. cerevisiae S288c was co-expressed. Expression of ADK1 showed a remarkable increase in AEC and co-expression of both the genes synergistically improved CALB activity. This study shows the importance of maintenance of cellular redox homeostasis and adenylate energy charge during recombinant CALB expression in P. pastoris.
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23
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Parimi NS, Durie IA, Wu X, Niyas AMM, Eiteman MA. Eliminating acetate formation improves citramalate production by metabolically engineered Escherichia coli. Microb Cell Fact 2017. [PMID: 28637476 PMCID: PMC5480221 DOI: 10.1186/s12934-017-0729-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Citramalate, a chemical precursor to the industrially important methacrylic acid (MAA), can be synthesized using Escherichia coli overexpressing citramalate synthase (cimA gene). Deletion of gltA encoding citrate synthase and leuC encoding 3-isopropylmalate dehydratase were critical to achieving high citramalate yields. Acetate is an undesirable by-product potentially formed from pyruvate and acetyl-CoA, the precursors of citramalate during aerobic growth of E. coli. This study investigated strategies to minimize acetate and maximize citramalate production in E. coli mutants expressing the cimA gene. RESULTS Key knockouts that minimized acetate formation included acetate kinase (ackA), phosphotransacetylase (pta), and in particular pyruvate oxidase (poxB). Deletion of glucose 6-phosphate dehydrogenase (zwf) and ATP synthase (atpFH) aimed at improving glycolytic flux negatively impacted cell growth and citramalate accumulation in shake flasks. In a repetitive fed-batch process, E. coli gltA leuC ackA-pta poxB overexpressing cimA generated 54.1 g/L citramalate with a yield of 0.64 g/g glucose (78% of theoretical maximum yield), and only 1.4 g/L acetate in 87 h. CONCLUSIONS This study identified the gene deletions critical to reducing acetate accumulation during aerobic growth and citramalate production in metabolically engineered E. coli strains. The citramalate yield and final titer relative to acetate at the end of the fed-batch process are the highest reported to date (a mass ratio of citramalate to acetate of nearly 40) without being detrimental to citramalate productivity, significantly improving a potential process for the production of this five-carbon chemical.
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Affiliation(s)
- Naga Sirisha Parimi
- School of Chemical, Materials and Biomedical Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, 30602, USA
| | - Ian A Durie
- School of Chemical, Materials and Biomedical Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, 30602, USA
| | - Xianghao Wu
- School of Chemical, Materials and Biomedical Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, 30602, USA
| | - Afaq M M Niyas
- School of Chemical, Materials and Biomedical Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, 30602, USA
| | - Mark A Eiteman
- School of Chemical, Materials and Biomedical Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, 30602, USA.
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24
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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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25
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Liu M, Yao L, Xian M, Ding Y, Liu H, Zhao G. Deletion of arcA increased the production of acetyl-CoA-derived chemicals in recombinant Escherichia coli. Biotechnol Lett 2015; 38:97-101. [PMID: 26362674 DOI: 10.1007/s10529-015-1953-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 09/01/2015] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Acetyl-CoA is used to produce many valuable metabolites in Escherichia coli. However, acetate overflow is a major shortcoming. Knockout of the global regulator gene, arcA, may solve this problem. RESULTS The arcA gene of E. coli BL21(DE3) was knocked out, and the production of phloroglucinol (PG) and 3-hydroxypropionate (3HP), both derived from acetyl-CoA, were used to evaluate its effect. The arcA mutants had higher cell yields and higher glucose utilization efficiencies than the corresponding control strains, and the productions of PG and 3HP were 0.92 g/l and 0.27 g/l, respectively; more than twice that of the control strains. Furthermore, arcA knockout also showed significant repression on formation of acetate, the major byproduct in fermentation. Acetate concentrations were decreased 69.4 % and 87 % by arcA knockout during the production of PG and 3HP, respectively. CONCLUSIONS The arcA gene knockout is a solution to acetate overflow and may improve production of a wide range of acetyl-CoA-derived metabolites.
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Affiliation(s)
- Min Liu
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lan Yao
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Mo Xian
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
| | - Yamei Ding
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Huizhou Liu
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
| | - Gao Zhao
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
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26
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Volmer J, Schmid A, Bühler B. Guiding bioprocess design by microbial ecology. Curr Opin Microbiol 2015; 25:25-32. [DOI: 10.1016/j.mib.2015.02.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 02/26/2015] [Accepted: 02/26/2015] [Indexed: 12/20/2022]
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Matsuoka Y, Shimizu K. Current status and future perspectives of kinetic modeling for the cell metabolism with incorporation of the metabolic regulation mechanism. BIORESOUR BIOPROCESS 2015. [DOI: 10.1186/s40643-014-0031-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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Shimizu K. Metabolic Regulation and Coordination of the Metabolism in Bacteria in Response to a Variety of Growth Conditions. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2015; 155:1-54. [PMID: 25712586 DOI: 10.1007/10_2015_320] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Living organisms have sophisticated but well-organized regulation system. It is important to understand the metabolic regulation mechanisms in relation to growth environment for the efficient design of cell factories for biofuels and biochemicals production. Here, an overview is given for carbon catabolite regulation, nitrogen regulation, ion, sulfur, and phosphate regulations, stringent response under nutrient starvation as well as oxidative stress regulation, redox state regulation, acid-shock, heat- and cold-shock regulations, solvent stress regulation, osmoregulation, and biofilm formation, and quorum sensing focusing on Escherichia coli metabolism and others. The coordinated regulation mechanisms are of particular interest in getting insight into the principle which governs the cell metabolism. The metabolism is controlled by both enzyme-level regulation and transcriptional regulation via transcription factors such as cAMP-Crp, Cra, Csr, Fis, P(II)(GlnB), NtrBC, CysB, PhoR/B, SoxR/S, Fur, MarR, ArcA/B, Fnr, NarX/L, RpoS, and (p)ppGpp for stringent response, where the timescales for enzyme-level and gene-level regulations are different. Moreover, multiple regulations are coordinated by the intracellular metabolites, where fructose 1,6-bisphosphate (FBP), phosphoenolpyruvate (PEP), and acetyl-CoA (AcCoA) play important roles for enzyme-level regulation as well as transcriptional control, while α-ketoacids such as α-ketoglutaric acid (αKG), pyruvate (PYR), and oxaloacetate (OAA) play important roles for the coordinated regulation between carbon source uptake rate and other nutrient uptake rate such as nitrogen or sulfur uptake rate by modulation of cAMP via Cya.
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Affiliation(s)
- Kazuyuki Shimizu
- Kyushu Institute of Technology, Iizuka, Fukuoka, 820-8502, Japan. .,Institute of Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0017, Japan.
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A novel cytosolic NADH:quinone oxidoreductase from Methanothermobacter marburgensis. Biosci Rep 2014; 34:e00167. [PMID: 25372605 PMCID: PMC4274662 DOI: 10.1042/bsr20140143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Methanothermobacter marburgensis is a strictly anaerobic, thermophilic methanogenic archaeon that uses methanogenesis to convert H2 and CO2 to energy. M. marburgensis is one of the best-studied methanogens, and all genes required for methanogenic metabolism have been identified. Nonetheless, the present study describes a gene (Gene ID 9704440) coding for a putative NAD(P)H:quinone oxidoreductase that has not yet been identified as part of the metabolic machinery. The gene product, MmNQO, was successfully expressed, purified and characterized biochemically, as well as structurally. MmNQO was identified as a flavin-dependent NADH:quinone oxidoreductase with the capacity to oxidize NADH in the presence of a wide range of electron acceptors, whereas NADPH was oxidized with only three acceptors. The 1.50 Å crystal structure of MmNQO features a homodimeric enzyme where each monomer comprises 196 residues folding into flavodoxin-like α/β domains with non-covalently bound FMN (flavin mononucleotide). The closest structural homologue is the modulator of drug activity B from Streptococcus mutans with 1.6 Å root-mean-square deviation on 161 Cα atoms and 28% amino-acid sequence identity. The low similarity at sequence and structural level suggests that MmNQO is unique among NADH:quinone oxidoreductases characterized to date. Based on preliminary bioreactor experiments, MmNQO could provide a useful tool to prevent overflow metabolism in applications that require cells with high energy demand. A novel NADH:quinone oxidoreductase, MmNQO, from Methanothermobacter marburgensis was identified. MmNQO oxidizes NADH with several electron acceptors and is structurally similar to bacterial MdaB. It is localized in the cytosol and may provide a useful tool to prevent overflow metabolism.
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Singh AB, Mukherjee KJ. Supplementation of substrate uptake gene enhances the expression of rhIFN-β in high cell density fed-batch cultures of Escherichia coli. Mol Biotechnol 2013. [PMID: 23180218 DOI: 10.1007/s12033-012-9611-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Over-expression of recombinant proteins in Escherichia coli triggers a metabolic stress response which causes a sharp decline in both growth and product formation rates post induction. We identified a key down-regulated substrate utilization gene, glycerol kinase (glpK), whose up-regulation could help alleviate this stress response. In a proof of principal study conducted in shake flask cultures, the glpK gene under the "ara" promoter in a pPROLar.A122 vector was co-transformed along with the recombinant interferon-β (rhIFN-β) gene in a pET22b vector into E. coli BL-21(DE3) cells. Co-expression of glpK improved the expression levels of rhIFN-β in glycerol containing medium, while no such gain was observed in medium without glycerol. This study was extended to high cell density fed-batch cultures where exponential feeding of complex substrates was done to increase biomass and hence product titers. For this we first constructed a modified E. coli strain BL-21(glpK (+)) where the glpK gene was inserted downstream of the ibpA promoter in the host chromosome. There was a significant improvement in growth as well as expression levels of rhIFN-β in this modified strain when the feed medium contained high glycerol. A final product concentration of 4.8 g/l of rhIFN-β was obtained with the modified strain which was 35 % higher than the control.
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Affiliation(s)
- Anuradha B Singh
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India.
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Engineering NAD+ availability for Escherichia coli whole-cell biocatalysis: a case study for dihydroxyacetone production. Microb Cell Fact 2013; 12:103. [PMID: 24209782 PMCID: PMC3831814 DOI: 10.1186/1475-2859-12-103] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 11/05/2013] [Indexed: 01/29/2023] Open
Abstract
Background Whole-cell redox biocatalysis has been intensively explored for the production of valuable compounds because excellent selectivity is routinely achieved. Although the cellular cofactor level, redox state and the corresponding enzymatic activity are expected to have major effects on the performance of the biocatalysts, our ability remains limited to predict the outcome upon variation of those factors as well as the relationship among them. Results In order to investigate the effects of cofactor availability on whole-cell redox biocatalysis, we devised recombinant Escherichia coli strains for the production of dihydroxyacetone (DHA) catalyzed by the NAD+-dependent glycerol dehydrogenase (GldA). In this model system, a water-forming NAD+ oxidase (NOX) and a NAD+ transporter (NTT4) were also co-expressed for cofactor regeneration and extracellular NAD+ uptake, respectively. We found that cellular cofactor level, NAD+/NADH ratio and NOX activity were not only strain-dependent, but also growth condition-dependent, leading to significant differences in specific DHA titer among different whole-cell biocatalysts. The host E. coli DH5α had the highest DHA specific titer of 0.81 g/gDCW with the highest NAD+/NADH ratio of 6.7 and NOX activity of 3900 U. The biocatalyst had a higher activity when induced with IPTG at 37°C for 8 h compared with those at 30°C for 8 h and 18 h. When cells were transformed with the ntt4 gene, feeding NAD+ during the cell culture stage increased cellular NAD(H) level by 1.44 fold and DHA specific titer by 1.58 fold to 2.13 g/gDCW. Supplementing NAD+ during the biotransformation stage was also beneficial to cellular NAD(H) level and DHA production, and the highest DHA productivity reached 0.76 g/gDCW/h. Cellular NAD(H) level, NAD+/NADH ratio, and NOX and GldA activity dropped over time during the biotransformation process. Conclusions High NAD+/NADH ratio driving by NOX was very important for DHA production. Once cofactor was efficiently cycled, high cellular NAD(H) level was also beneficial for whole-cell redox biocatalysis. Our results indicated that NAD+ transporter could be applied to manipulate redox cofactor level for biocatalysis. Moreover, we suggested that genetically designed redox transformation should be carefully profiled for further optimizing whole-cell biocatalysis.
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Mahmoudi Azar L, Mehdizadeh Aghdam E, Karimi F, Haghshenas B, Barzegari A, Yaghmaei P, Hejazi MS. Influence of Foreign DNA Introduction and Periplasmic Expression of Recombinant Human Interleukin-2 on Hydrogen Peroxide Quantity and Catalase Activity in Escherichia coli. Adv Pharm Bull 2013; 3:395-402. [PMID: 24312866 PMCID: PMC3848214 DOI: 10.5681/apb.2013.063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 04/18/2013] [Accepted: 04/22/2013] [Indexed: 11/17/2022] Open
Abstract
PURPOSE Oxidative stress is generated through imbalance between composing and decomposing of reactive oxygen species (ROS). This kind of stress was rarely discussed in connection with foreign protein production in Escherichia coli. Effect of cytoplasmic recombinant protein expression on Hydrogen peroxide concentration and catalase activity was previously reported. In comparison with cytoplasm, periplasmic space has different oxidative environment. Therefore, in present study we describe the effect of periplasmic expression of recombinant human interleukin-2 (hIL-2) on H2O2 concentration and catalase activity in Escherichia coli and their correlation with cell growth. METHODS Having constructed pET2hIL2 vector, periplasmic expression of hIL-2 was confirmed. Then, H2O2 concentration and catalase activity were determined at various ODs. Wild type and empty vector transformed cells were used as negative controls. RESULTS It was shown that H2O2 concentration in hIL-2 expressing cells was significantly higher than its concentration in wild type and empty vector transformed cells. Catalase activity and growth rate reduced significantly in hIL-2 expressing cells compared to empty vector transformed and wild type cells. Variation of H2O2 concentration and catalase activity is intensive in periplasmic hIL-2 expressing cells than empty vector containing cells. Correlation between H2O2 concentration elevation and catalase activity reduction with cell growth depletion are also demonstrated. CONCLUSION Periplasmic expression of recombinant hIL-2 elevates the host cell's hydrogen peroxide concentration possibly due to reduced catalase activity which has consequent suppressive effect on growth rate.
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Affiliation(s)
- Lena Mahmoudi Azar
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Elnaz Mehdizadeh Aghdam
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Farrokh Karimi
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Biotechnology, Faculty of Science, Maragheh University, Maragheh, Iran
| | - Babak Haghshenas
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
- Institute of Bioscience, University of Putra Malaysia, Kualalumpur, Malaysia
| | - Abolfazl Barzegari
- Research Center of Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Mohammad Saeid Hejazi
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
- Faculty of Advanced Biomedical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
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Shimizu K. Metabolic Regulation of a Bacterial Cell System with Emphasis on Escherichia coli Metabolism. ISRN BIOCHEMISTRY 2013; 2013:645983. [PMID: 25937963 PMCID: PMC4393010 DOI: 10.1155/2013/645983] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 10/25/2012] [Indexed: 12/19/2022]
Abstract
It is quite important to understand the overall metabolic regulation mechanism of bacterial cells such as Escherichia coli from both science (such as biochemistry) and engineering (such as metabolic engineering) points of view. Here, an attempt was made to clarify the overall metabolic regulation mechanism by focusing on the roles of global regulators which detect the culture or growth condition and manipulate a set of metabolic pathways by modulating the related gene expressions. For this, it was considered how the cell responds to a variety of culture environments such as carbon (catabolite regulation), nitrogen, and phosphate limitations, as well as the effects of oxygen level, pH (acid shock), temperature (heat shock), and nutrient starvation.
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Affiliation(s)
- Kazuyuki Shimizu
- Kyushu Institute of Technology, Fukuoka, Iizuka 820-8502, Japan
- Institute of Advanced Bioscience, Keio University, Yamagata, Tsuruoka 997-0017, Japan
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Ruiz JA, de Almeida A, Godoy MS, Mezzina MP, Bidart GN, Méndez BS, Pettinari MJ, Nikel PI. Escherichia coli redox mutants as microbial cell factories for the synthesis of reduced biochemicals. Comput Struct Biotechnol J 2013; 3:e201210019. [PMID: 24688679 PMCID: PMC3962086 DOI: 10.5936/csbj.201210019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 12/09/2012] [Accepted: 12/13/2012] [Indexed: 11/23/2022] Open
Abstract
Bioprocesses conducted under conditions with restricted O2 supply are increasingly exploited for the synthesis of reduced biochemicals using different biocatalysts. The model facultative aerobe Escherichia coli, the microbial cell factory par excellence, has elaborate sensing and signal transduction mechanisms that respond to the availability of electron acceptors and alternative carbon sources in the surrounding environment. In particular, the ArcBA and CreBC two-component signal transduction systems are largely responsible for the metabolic regulation of redox control in response to O2 availability and carbon source utilization, respectively. Significant advances in the understanding of the biochemical, genetic, and physiological duties of these regulatory systems have been achieved in recent years. This situation allowed to rationally-design novel engineering approaches that ensure optimal carbon and energy flows within central metabolism, as well as to manipulate redox homeostasis, in order to optimize the production of industrially-relevant metabolites. In particular, metabolic flux analysis provided new clues to understand the metabolic regulation mediated by the ArcBA and CreBC systems. Genetic manipulation of these regulators proved useful for designing microbial cells factories tailored for the synthesis of reduced biochemicals with added value, such as poly(3-hydroxybutyrate), under conditions with restricted O2 supply. This network-wide strategy is in contrast with traditional metabolic engineering approaches, that entail direct modification of the pathway(s) at stake, and opens new avenues for the targeted modulation of central catabolic pathways at the transcriptional level.
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Affiliation(s)
- Jimena A Ruiz
- Departamento de Química Biológica (IQUIBICEN-CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina ; Instituto de Biociencias Agrícolas y Ambientales (INBA-CONICET), Facultad de Agronomía, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Alejandra de Almeida
- Departamento de Química Biológica (IQUIBICEN-CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Manuel S Godoy
- Departamento de Química Biológica (IQUIBICEN-CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Mariela P Mezzina
- Departamento de Química Biológica (IQUIBICEN-CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Gonzalo N Bidart
- Instituto de Investigaciones Biotecnológicas "Dr. Rodolfo A. Ugalde" (IIB-CONICET), Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina
| | - Beatriz S Méndez
- Departamento de Química Biológica (IQUIBICEN-CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - M Julia Pettinari
- Departamento de Química Biológica (IQUIBICEN-CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Pablo I Nikel
- Departamento de Química Biológica (IQUIBICEN-CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina ; Instituto de Investigaciones Biotecnológicas "Dr. Rodolfo A. Ugalde" (IIB-CONICET), Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina
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Recent advances in engineering the central carbon metabolism of industrially important bacteria. Microb Cell Fact 2012; 11:50. [PMID: 22545791 PMCID: PMC3461431 DOI: 10.1186/1475-2859-11-50] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 04/30/2012] [Indexed: 01/19/2023] Open
Abstract
This paper gives an overview of the recent advances in engineering the central carbon metabolism of the industrially important bacteria Escherichia coli, Bacillus subtilis, Corynobacterium glutamicum, Streptomyces spp., Lactococcus lactis and other lactic acid bacteria. All of them are established producers of important classes of products, e.g. proteins, amino acids, organic acids, antibiotics, high-value metabolites for the food industry and also, promising producers of a large number of industrially or therapeutically important chemicals. Optimization of existing or introduction of new cellular processes in these microorganisms is often achieved through manipulation of targets that reside at major points of central metabolic pathways, such as glycolysis, gluconeogenesis, the pentose phosphate pathway and the tricarboxylic acid cycle with the glyoxylate shunt. Based on the huge progress made in recent years in biochemical, genetic and regulatory studies, new fascinating engineering approaches aim at ensuring an optimal carbon and energy flow within central metabolism in order to achieve optimized metabolite production.
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36
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Effect of feeding strategy on l-tryptophan production by recombinant Escherichia coli. ANN MICROBIOL 2012. [DOI: 10.1007/s13213-012-0419-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
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Response of Pseudomonas putida KT2440 to increased NADH and ATP demand. Appl Environ Microbiol 2011; 77:6597-605. [PMID: 21803911 DOI: 10.1128/aem.05588-11] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Adenosine phosphate and NAD cofactors play a vital role in the operation of cell metabolism, and their levels and ratios are carefully regulated in tight ranges. Perturbations of the consumption of these metabolites might have a great impact on cell metabolism and physiology. Here, we investigated the impact of increased ATP hydrolysis and NADH oxidation rates on the metabolism of Pseudomonas putida KT2440 by titration of 2,4-dinitrophenol (DNP) and overproduction of a water-forming NADH oxidase, respectively. Both perturbations resulted in a reduction of the biomass yield and, as a consequence of the uncoupling of catabolic and anabolic activities, in an amplification of the net NADH regeneration rate. However, a stimulation of the specific carbon uptake rate was observed only when P. putida was challenged with very high 2,4-dinitrophenol concentrations and was comparatively unaffected by recombinant NADH oxidase activity. This behavior contrasts with the comparably sensitive performance described, for example, for Escherichia coli or Saccharomyces cerevisiae. The apparent robustness of P. putida metabolism indicates that it possesses a certain buffering capacity and a high flexibility to adapt to and counteract different stresses without showing a distinct phenotype. These findings are important, e.g., for the development of whole-cell redox biocatalytic processes that impose equivalent burdens on the cell metabolism: stoichiometric consumption of (reduced) redox cofactors and increased energy expenditures, due to the toxicity of the biocatalytic compounds.
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38
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Metabolic regulation in Escherichia coli in response to culture environments via global regulators. Biotechnol J 2011; 6:1330-41. [DOI: 10.1002/biot.201000447] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 02/14/2011] [Accepted: 02/16/2011] [Indexed: 11/07/2022]
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Gonidakis S, Finkel SE, Longo VD. E. coli hypoxia-inducible factor ArcA mediates lifespan extension in a lipoic acid synthase mutant by suppressing acetyl-CoA synthetase. Biol Chem 2011; 391:1139-47. [PMID: 20707605 DOI: 10.1515/bc.2010.120] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We have previously shown that both the hypoxia-inducible transcription factor ArcA and the PoxB/Acs bypass of the pyruvate dehydrogenase complex contribute to extended lifespan in Escherichia coli. In agreement with studies in higher eukaryotes, we also demonstrated that long-lived E. coli mutants, including LipA-deficient cells, are stress resistant. Here, we show that ArcA contributes to the enhanced lifespan and heat shock resistance of the lipA mutant by suppressing expression of the acetyl-CoA synthetase (acs) gene. The deletion of acs reversed the reduced lifespan of the lipA arcA mutant and promoted the accumulation of extracellular acetate, indicating that inhibition of carbon source uptake contributes to survival extension. However, Acs also sensitized cells lacking ArcA to heat shock, in the absence of extracellular acetate. These results provide evidence for the role of Acs in regulating lifespan and/or stress resistance by both carbon source uptake-dependent and -independent mechanisms.
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Affiliation(s)
- Stavros Gonidakis
- Integrative and Evolutionary Biology, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
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40
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Gonidakis S, Finkel SE, Longo VD. Genome-wide screen identifies Escherichia coli TCA-cycle-related mutants with extended chronological lifespan dependent on acetate metabolism and the hypoxia-inducible transcription factor ArcA. Aging Cell 2010; 9:868-81. [PMID: 20707865 DOI: 10.1111/j.1474-9726.2010.00618.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Single-gene mutants with extended lifespan have been described in several model organisms. We performed a genome-wide screen for long-lived mutants in Escherichia coli, which revealed strains lacking tricarboxylic acid (TCA)-cycle-related genes that exhibit longer stationary-phase survival and increased resistance to heat stress compared to wild-type. Extended lifespan in the sdhA mutant, lacking subunit A of succinate dehydrogenase, is associated with the reduced production of superoxide and increased stress resistance. On the other hand, the longer lifespan of the lipoic acid synthase mutant (lipA) is associated with reduced oxygen consumption and requires the acetate-producing enzyme pyruvate oxidase, as well as acetyl-CoA synthetase, the enzyme that converts extracellular acetate to acetyl-CoA. The hypoxia-inducible transcription factor ArcA, acting independently of acetate metabolism, is also required for maximum lifespan extension in the lipA and lpdA mutants, indicating that these mutations promote entry into a mode normally associated with a low-oxygen environment. Because analogous changes from respiration to fermentation have been observed in long-lived Saccharomyces cerevisiae and Caenorhabditis elegans strains, such metabolic alterations may represent an evolutionarily conserved strategy to extend lifespan.
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Affiliation(s)
- Stavros Gonidakis
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
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41
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Holm AK, Blank LM, Oldiges M, Schmid A, Solem C, Jensen PR, Vemuri GN. Metabolic and transcriptional response to cofactor perturbations in Escherichia coli. J Biol Chem 2010; 285:17498-506. [PMID: 20299454 DOI: 10.1074/jbc.m109.095570] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Metabolic cofactors such as NADH and ATP play important roles in a large number of cellular reactions, and it is of great interest to dissect the role of these cofactors in different aspects of metabolism. Toward this goal, we overexpressed NADH oxidase and the soluble F1-ATPase in Escherichia coli to lower the level of NADH and ATP, respectively. We used a global interaction network, comprising of protein interactions, transcriptional regulation, and metabolic networks, to integrate data from transcription profiles, metabolic fluxes, and the metabolite levels. We identified high-scoring networks for the two strains. The results revealed a smaller, but denser network for perturbations of ATP level, compared with that of NADH level. The action of many global transcription factors such as ArcA, Fnr, CRP, and IHF commonly involved both NADH and ATP, whereas others responded to either ATP or NADH. Overexpressing NADH oxidase invokes response in widespread aspects of metabolism involving the redox cofactors (NADH and NADPH), whereas ATPase has a more focused response to restore ATP level by enhancing proton translocation mechanisms and repressing biosynthesis. Interestingly, NADPH played a key role in restoring redox homeostasis through the concerted activity of isocitrate dehydrogenase and UdhA transhydrogenase. We present a reconciled network of regulation that illustrates the overlapping and distinct aspects of metabolism controlled by NADH and ATP. Our study contributes to the general understanding of redox and energy metabolism and should help in developing metabolic engineering strategies in E. coli.
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Affiliation(s)
- Anders K Holm
- Department of Systems Biology, Center for Systems Microbiology, Technical University of Denmark, Denmark
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42
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Orencio-Trejo M, Utrilla J, Fernández-Sandoval MT, Huerta-Beristain G, Gosset G, Martinez A. Engineering the Escherichia coli fermentative metabolism. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2010; 121:71-107. [PMID: 20182928 DOI: 10.1007/10_2009_61] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Fermentative metabolism constitutes a fundamental cellular capacity for industrial biocatalysis. Escherichia coli is an important microorganism in the field of metabolic engineering for its well-known molecular characteristics and its rapid growth. It can adapt to different growth conditions and is able to grow in the presence or absence of oxygen. Through the use of metabolic pathway engineering and bioprocessing techniques, it is possible to explore the fundamental cellular properties and to exploit its capacity to be applied as industrial biocatalysts to produce a wide array of chemicals. The objective of this chapter is to review the metabolic engineering efforts carried out with E. coli by manipulating the central carbon metabolism and fermentative pathways to obtain strains that produce metabolites with high titers, such as ethanol, alanine, lactate and succinate.
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Affiliation(s)
- M Orencio-Trejo
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, 510-3, Cuernavaca, Morelos, 62250, México
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43
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Toward systematic metabolic engineering based on the analysis of metabolic regulation by the integration of different levels of information. Biochem Eng J 2009. [DOI: 10.1016/j.bej.2009.06.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Pan Z, Cunningham DS, Zhu T, Ye K, Koepsel RR, Domach MM, Ataai MM. Enhanced recombinant protein production in pyruvate kinase mutant of Bacillus subtilis. Appl Microbiol Biotechnol 2009; 85:1769-78. [PMID: 19787348 DOI: 10.1007/s00253-009-2244-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2009] [Revised: 09/01/2009] [Accepted: 09/03/2009] [Indexed: 10/20/2022]
Abstract
Previous work demonstrated that acetate production was substantially lower in pyruvate kinase (pyk) mutant of Bacillus subtilis. The significantly lower acetate production in the pyk mutant is hypothesized to have positive effect on recombinant protein production either by lifting the inhibitory effect of acetate accumulation in the medium or redirecting the metabolic fluxes beneficial to biomass/protein synthesis. In this study, the impact of the pyk mutation on recombinant protein production was investigated. Green fluorescent protein (GFP+) was selected as a model protein and constitutively expressed in both the wild-type strain and a pyk mutant. In batch cultures, the pyk mutant produced 3-fold higher levels of recombinant protein when grown on glucose as carbon source. Experimental measurements and theoretical analysis show that the higher protein yield of the mutant is not due to removal of an acetate-associated inhibition of expression or gene dosage or protein stability but a much lower acetate production in the mutant allows for a greater fraction of carbon intake to be directed to protein synthesis.
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Affiliation(s)
- Zhiwei Pan
- Department of Chemical Engineering, University of Pittsburgh, 1249 Benedum Hall, Pittsburgh, PA 15261, USA
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Zhou J, Liu L, Shi Z, Du G, Chen J. ATP in current biotechnology: regulation, applications and perspectives. Biotechnol Adv 2008; 27:94-101. [PMID: 19026736 DOI: 10.1016/j.biotechadv.2008.10.005] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Revised: 08/13/2008] [Accepted: 10/14/2008] [Indexed: 11/25/2022]
Abstract
Adenosine tri-phosphate (ATP), the most important energy source for metabolic reactions and pathways, plays a vital role in the growth of industrial strain and the production of target metabolites. In this review, current advances in manipulating ATP in industrial strains, including altering NADH availability, and regulating NADH oxidation pathway, oxygen supply, proton gradient, the electron transfer chain activity and the F(0)F(1)-ATPase activity, are summarized and discussed. By applying these strategies, optimal product concentrations, yields and productivity in industrial biotechnology have been achieved. Furthermore, the mechanisms by which ATP extends the substrate utilization spectra and enhances the ability to challenge harsh environmental stress have been elucidated. Finally, three critical issues related to ATP manipulation have been addressed.
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Affiliation(s)
- Jingwen Zhou
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
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46
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NADH availability limits asymmetric biocatalytic epoxidation in a growing recombinant Escherichia coli strain. Appl Environ Microbiol 2008; 74:1436-46. [PMID: 18192422 DOI: 10.1128/aem.02234-07] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Styrene can efficiently be oxidized to (S)-styrene oxide by recombinant Escherichia coli expressing the styrene monooxygenase genes styAB from Pseudomonas sp. strain VLB120. Targeting microbial physiology during whole-cell redox biocatalysis, we investigated the interdependency of styrene epoxidation, growth, and carbon metabolism on the basis of mass balances obtained from continuous two-liquid-phase cultures. Full induction of styAB expression led to growth inhibition, which could be attenuated by reducing expression levels. Operation at subtoxic substrate and product concentrations and variation of the epoxidation rate via the styrene feed concentration allowed a detailed analysis of carbon metabolism and bioconversion kinetics. Fine-tuned styAB expression and increasing specific epoxidation rates resulted in decreasing biomass yields, increasing specific rates for glucose uptake and the tricarboxylic acid (TCA) cycle, and finally saturation of the TCA cycle and acetate formation. Interestingly, the biocatalysis-related NAD(P)H consumption was 3.2 to 3.7 times higher than expected from the epoxidation stoichiometry. Possible reasons include uncoupling of styrene epoxidation and NADH oxidation and increased maintenance requirements during redox biocatalysis. At epoxidation rates of above 21 micromol per min per g cells (dry weight), the absence of limitations by O(2) and styrene and stagnating NAD(P)H regeneration rates indicated that NADH availability limited styrene epoxidation. During glucose-limited growth, oxygenase catalysis might induce regulatory stress responses, which attenuate excessive glucose catabolism and thus limit NADH regeneration. Optimizing metabolic and/or regulatory networks for efficient redox biocatalysis instead of growth (yield) is likely to be the key for maintaining high oxygenase activities in recombinant E. coli.
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47
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De Mey M, De Maeseneire S, Soetaert W, Vandamme E. Minimizing acetate formation in E. coli fermentations. J Ind Microbiol Biotechnol 2007; 34:689-700. [PMID: 17668256 DOI: 10.1007/s10295-007-0244-2] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2006] [Accepted: 07/08/2007] [Indexed: 10/23/2022]
Abstract
Escherichia coli remains the best-established production organism in industrial biotechnology. However, when aerobic fermentation runs at high growth rates, considerable amounts of acetate are accumulated as by-product. This by-product has negative effects on growth and protein production. Over the last 20 years, substantial research efforts have been expended on reducing acetate accumulation during aerobic growth of E. coli on glucose. From the onset it was clear that this quest would not be a simple or uncomplicated one. Simple deletion of the acetate pathway reduced the acetate accumulation, but other by-products were formed. This mini review gives a clear outline of these research efforts and their outcome, including bioprocess level approaches and genetic approaches. Recently, the latter seems to have some promising results.
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Affiliation(s)
- Marjan De Mey
- Laboratory of Industrial Microbiology and Biocatalysis, Department of Biochemical and Microbial Technology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium.
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Chou CP. Engineering cell physiology to enhance recombinant protein production in Escherichia coli. Appl Microbiol Biotechnol 2007; 76:521-32. [PMID: 17571257 DOI: 10.1007/s00253-007-1039-0] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Revised: 05/08/2007] [Accepted: 05/21/2007] [Indexed: 11/26/2022]
Abstract
The advent of recombinant DNA technology has revolutionized the strategies for protein production. Due to the well-characterized genome and a variety of mature tools available for genetic manipulation, Escherichia coli is still the most common workhorse for recombinant protein production. However, the culture for industrial applications often presents E. coli cells with a growth condition that is significantly different from their natural inhabiting environment in the gastrointestinal tract, resulting in deterioration in cell physiology and limitation in cell's productivity. It has been recognized that innovative design of genetically engineered strains can highly increase the bioprocess yield with minimum investment on the capital and operating costs. Nevertheless, most of these genetic manipulations, by which traits are implanted into the workhorse through recombinant DNA technology, for enhancing recombinant protein productivity often translate into the challenges that deteriorate cell physiology or even jeopardize cell survival. An in-depth understanding of these challenges and their corresponding cellular response at the molecular level becomes crucial for developing superior strains that are more physiologically adaptive to the production environment to improve culture productivity. With the accumulated knowledge in cell physiology, whose importance to gene overexpression was to some extent undervalued previously, this review is intended to focus on the recent biotechnological advancement in engineering cell physiology to enhance recombinant protein production in E. coli.
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Affiliation(s)
- C Perry Chou
- Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON, Canada, N2L 3G1.
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Wong SMS, Alugupalli KR, Ram S, Akerley BJ. The ArcA regulon and oxidative stress resistance in Haemophilus influenzae. Mol Microbiol 2007; 64:1375-90. [PMID: 17542927 PMCID: PMC1974803 DOI: 10.1111/j.1365-2958.2007.05747.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/13/2007] [Indexed: 01/11/2023]
Abstract
Haemophilus influenzae transits between niches within the human host that are predicted to differ in oxygen levels. The ArcAB two-component signal transduction system controls gene expression in response to respiratory conditions of growth and has been implicated in bacterial pathogenesis, yet the mechanism is not understood. We undertook a genome-scale study to identify genes of the H. influenzae ArcA regulon. Deletion of arcA resulted in increased anaerobic expression of genes of the respiratory chain and of H. influenzae's partial tricarboxylic acid cycle, and decreased anaerobic expression levels of genes of polyamine metabolism, and iron sequestration. Deletion of arcA also conferred a susceptibility to transient exposure to hydrogen peroxide that was greater following anaerobic growth than after aerobic growth. Array data revealed that the dps gene, not previously assigned to the ArcA modulon in bacteria, exhibited decreased expression in the arcA mutant. Deletion of dps resulted in hydrogen peroxide sensitivity and complementation restored resistance, providing insight into the previously uncharacterized mechanism of arcA-mediated H(2)O(2) resistance. The results indicate a role for H. influenzae arcA and dps in pre-emptive defence against transitions from growth in low oxygen environments to aerobic exposure to hydrogen peroxide, an antibacterial oxidant produced by phagocytes during infection.
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Affiliation(s)
- Sandy M S Wong
- Department of Molecular Genetics and Microbiology, University of Massachusetts Medical SchoolWorcester, MA 01655, USA.
| | - Kishore R Alugupalli
- Department of Molecular Genetics and Microbiology, University of Massachusetts Medical SchoolWorcester, MA 01655, USA.
| | - Sanjay Ram
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical SchoolWorcester, MA 01605, USA.
| | - Brian J Akerley
- Department of Molecular Genetics and Microbiology, University of Massachusetts Medical SchoolWorcester, MA 01655, USA.
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Eiteman MA, Altman E. Overcoming acetate in Escherichia coli recombinant protein fermentations. Trends Biotechnol 2006; 24:530-6. [PMID: 16971006 DOI: 10.1016/j.tibtech.2006.09.001] [Citation(s) in RCA: 259] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Revised: 08/04/2006] [Accepted: 09/01/2006] [Indexed: 11/18/2022]
Abstract
Escherichia coli is the organism of choice for the expression of a wide variety of recombinant proteins for therapeutic, diagnostic and industrial applications. E. coli generates acetic acid (acetate) as an undesirable by-product that has several negative effects on protein production. Various strategies have been developed to limit acetate accumulation or reduce its negative effects to increase the productivity of recombinant proteins. This article reviews recent strategies for reducing or eliminating acetate, including approaches that optimize the protein production process as well as those that involve modifying the host organism itself.
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Affiliation(s)
- Mark A Eiteman
- Center for Molecular BioEngineering, University of Georgia, Athens, GA 30602, USA
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