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Kaplan NA, Islam KN, Kanis FC, Verderber JR, Wang X, Jones JA, Koffas MAG. Simultaneous glucose and xylose utilization by an Escherichia coli catabolite repression mutant. Appl Environ Microbiol 2024; 90:e0216923. [PMID: 38289128 PMCID: PMC10880614 DOI: 10.1128/aem.02169-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 12/11/2023] [Indexed: 02/22/2024] Open
Abstract
As advances are made toward the industrial feasibility of mass-producing biofuels and commodity chemicals with sugar-fermenting microbes, high feedstock costs continue to inhibit commercial application. Hydrolyzed lignocellulosic biomass represents an ideal feedstock for these purposes as it is cheap and prevalent. However, many microbes, including Escherichia coli, struggle to efficiently utilize this mixture of hexose and pentose sugars due to the regulation of the carbon catabolite repression (CCR) system. CCR causes a sequential utilization of sugars, rather than simultaneous utilization, resulting in reduced carbon yield and complex process implications in fed-batch fermentation. A mutant of the gene encoding the cyclic AMP receptor protein, crp*, has been shown to disable CCR and improve the co-utilization of mixed sugar substrates. Here, we present the strain construction and characterization of a site-specific crp* chromosomal mutant in E. coli BL21 star (DE3). The crp* mutant strain demonstrates simultaneous consumption of glucose and xylose, suggesting a deregulated CCR system. The proteomics further showed that glucose was routed to the C5 carbon utilization pathways to support both de novo nucleotide synthesis and energy production in the crp* mutant strain. Metabolite analyses further show that overflow metabolism contributes to the slower growth in the crp* mutant. This highly characterized strain can be particularly beneficial for chemical production by simultaneously utilizing both C5 and C6 substrates from lignocellulosic biomass.IMPORTANCEAs the need for renewable biofuel and biochemical production processes continues to grow, there is an associated need for microbial technology capable of utilizing cheap, widely available, and renewable carbon substrates. This work details the construction and characterization of the first B-lineage Escherichia coli strain with mutated cyclic AMP receptor protein, Crp*, which deregulates the carbon catabolite repression (CCR) system and enables the co-utilization of multiple sugar sources in the growth medium. In this study, we focus our analysis on glucose and xylose utilization as these two sugars are the primary components in lignocellulosic biomass hydrolysate, a promising renewable carbon feedstock for industrial bioprocesses. This strain is valuable to the field as it enables the use of mixed sugar sources in traditional fed-batch based approaches, whereas the wild-type carbon catabolite repression system leads to biphasic growth and possible buildup of non-preferential sugars, reducing process efficiency at scale.
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Affiliation(s)
- Nicholas A. Kaplan
- Department of Chemical, Paper, and Biomedical Engineering, Miami University, Oxford, Ohio, USA
| | - Khondokar Nowshin Islam
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Fiona C. Kanis
- Department of Chemical, Paper, and Biomedical Engineering, Miami University, Oxford, Ohio, USA
| | - Jack R. Verderber
- Department of Chemical, Paper, and Biomedical Engineering, Miami University, Oxford, Ohio, USA
| | - Xin Wang
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - J. Andrew Jones
- Department of Chemical, Paper, and Biomedical Engineering, Miami University, Oxford, Ohio, USA
| | - Mattheos A. G. Koffas
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York, USA
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Zhang X, Cao Y, Liu Y, Lei Y, Zhai R, Chen W, Shi G, Jin JM, Liang C, Tang SY. Designing glucose utilization "highway" for recombinant biosynthesis. Metab Eng 2023; 78:235-247. [PMID: 37394056 DOI: 10.1016/j.ymben.2023.06.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 06/28/2023] [Accepted: 06/29/2023] [Indexed: 07/04/2023]
Abstract
cAMP receptor protein (CRP) is known as a global regulatory factor mainly mediating carbon source catabolism. Herein, we successfully engineered CRP to develop microbial chassis cells with improved recombinant biosynthetic capability in minimal medium with glucose as single carbon source. The obtained best-performing cAMP-independent CRPmu9 mutant conferred both faster cell growth and a 133-fold improvement in expression level of lac promoter in presence of 2% glucose, compared with strain under regulation of CRPwild-type. Promoters free from "glucose repression" are advantageous for recombinant expression, as glucose is a frequently used inexpensive carbon source in high-cell-density fermentations. Transcriptome analysis demonstrated that the CRP mutant globally rewired cell metabolism, displaying elevated tricarboxylic acid cycle activity; reduced acetate formation; increased nucleotide biosynthesis; and improved ATP synthesis, tolerance, and stress-resistance activity. Metabolites analysis confirmed the enhancement of glucose utilization with the upregulation of glycolysis and glyoxylate-tricarboxylic acid cycle. As expected, an elevated biosynthetic capability was demonstrated with vanillin, naringenin and caffeic acid biosynthesis in strains regulated by CRPmu9. This study has expanded the significance of CRP optimization into glucose utilization and recombinant biosynthesis, beyond the conventionally designated carbon source utilization other than glucose. The Escherichiacoli cell regulated by CRPmu9 can be potentially used as a beneficial chassis for recombinant biosynthesis.
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Affiliation(s)
- Xuanxuan Zhang
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China; State Key Laboratory of Transducer Technology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yufeng Cao
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China; State Key Laboratory of Transducer Technology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ying Liu
- Yingsheng (Beijing) Biotechnology Co., Ltd., Beijing, 100081, China
| | - Yanyan Lei
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China; State Key Laboratory of Transducer Technology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ruixue Zhai
- Yingsheng (Beijing) Biotechnology Co., Ltd., Beijing, 100081, China
| | - Wei Chen
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China; State Key Laboratory of Transducer Technology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Guizhi Shi
- Yingsheng (Beijing) Biotechnology Co., Ltd., Beijing, 100081, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Jian-Ming Jin
- Beijing Key Laboratory of Plant Resources Research and Development, Beijing Technology and Business University, Beijing, 100048, China.
| | - Chaoning Liang
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China; State Key Laboratory of Transducer Technology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Shuang-Yan Tang
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China; State Key Laboratory of Transducer Technology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
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3
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Zeng J, Hong Y, Zhao N, Liu Q, Zhu W, Xiao L, Wang W, Chen M, Hong S, Wu L, Xue Y, Wang D, Niu J, Drlica K, Zhao X. A broadly applicable, stress-mediated bacterial death pathway regulated by the phosphotransferase system (PTS) and the cAMP-Crp cascade. Proc Natl Acad Sci U S A 2022; 119:e2118566119. [PMID: 35648826 PMCID: PMC9191683 DOI: 10.1073/pnas.2118566119] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 04/22/2022] [Indexed: 12/30/2022] Open
Abstract
Recent work indicates that killing of bacteria by diverse antimicrobial classes can involve reactive oxygen species (ROS), as if a common, self-destructive response to antibiotics occurs. However, the ROS-bacterial death theory has been challenged. To better understand stress-mediated bacterial death, we enriched spontaneous antideath mutants of Escherichia coli that survive treatment by diverse bactericidal agents that include antibiotics, disinfectants, and environmental stressors, without a priori consideration of ROS. The mutants retained bacteriostatic susceptibility, thereby ruling out resistance. Surprisingly, pan-tolerance arose from carbohydrate metabolism deficiencies in ptsI (phosphotransferase) and cyaA (adenyl cyclase); these genes displayed the activity of upstream regulators of a widely shared, stress-mediated death pathway. The antideath effect was reversed by genetic complementation, exogenous cAMP, or a Crp variant that bypasses cAMP binding for activation. Downstream events comprised a metabolic shift from the TCA cycle to glycolysis and to the pentose phosphate pathway, suppression of stress-mediated ATP surges, and reduced accumulation of ROS. These observations reveal how upstream signals from diverse stress-mediated lesions stimulate shared, late-stage, ROS-mediated events. Cultures of these stable, pan-tolerant mutants grew normally and were therefore distinct from tolerance derived from growth defects described previously. Pan-tolerance raises the potential for unrestricted disinfectant use to contribute to antibiotic tolerance and resistance. It also weakens host defenses, because three agents (hypochlorite, hydrogen peroxide, and low pH) affected by pan-tolerance are used by the immune system to fight infections. Understanding and manipulating the PtsI-CyaA-Crp–mediated death process can help better control pathogens and maintain beneficial microbiota during antimicrobial treatment.
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Affiliation(s)
- Jie Zeng
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Yuzhi Hong
- Public Health Research Institute, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Rutgers University, Newark, NJ 07103
- Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Rutgers University, Newark, NJ 07103
- Institute of Molecular Enzymology and School of Biology & Basic Medical Sciences, Medical College, Soochow University, Suzhou 215123, China
| | - Ningqiu Zhao
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Qianyu Liu
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen 361004, China
| | - Weiwei Zhu
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Lisheng Xiao
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Weijie Wang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Miaomiao Chen
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Shouqiang Hong
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Liwen Wu
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Yunxin Xue
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Dai Wang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Jianjun Niu
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen 361004, China
| | - Karl Drlica
- Public Health Research Institute, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Rutgers University, Newark, NJ 07103
- Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Rutgers University, Newark, NJ 07103
| | - Xilin Zhao
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
- Public Health Research Institute, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Rutgers University, Newark, NJ 07103
- Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Rutgers University, Newark, NJ 07103
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Zhao Z, Xian M, Liu M, Zhao G. Biochemical routes for uptake and conversion of xylose by microorganisms. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:21. [PMID: 32021652 PMCID: PMC6995148 DOI: 10.1186/s13068-020-1662-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 01/21/2020] [Indexed: 05/23/2023]
Abstract
Xylose is a major component of lignocellulose and the second most abundant sugar present in nature. Efficient utilization of xylose is required for the development of economically viable processes to produce biofuels and chemicals from biomass. However, there are still some bottlenecks in the bioconversion of xylose, including the fact that some microorganisms cannot assimilate xylose naturally and that the uptake and metabolism of xylose are inhibited by glucose, which is usually present with xylose in lignocellulose hydrolysate. To overcome these issues, numerous efforts have been made to discover, characterize, and engineer the transporters and enzymes involved in xylose utilization to relieve glucose inhibition and to develop recombinant microorganisms to produce fuels and chemicals from xylose. Here we describe a recent advancement focusing on xylose-utilizing pathways, biosynthesis of chemicals from xylose, and engineering strategies used to improve the conversion efficiency of xylose.
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Affiliation(s)
- Zhe Zhao
- 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
| | - Min Liu
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 China
| | - Guang 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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Sun J, Tian K, Wang J, Dong Z, Liu X, Permaul K, Singh S, Prior BA, Wang Z. Improved ethanol productivity from lignocellulosic hydrolysates by Escherichia coli with regulated glucose utilization. Microb Cell Fact 2018; 17:66. [PMID: 29720171 PMCID: PMC5930954 DOI: 10.1186/s12934-018-0915-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 04/24/2018] [Indexed: 12/03/2022] Open
Abstract
Background Lignocellulosic ethanol could offer a sustainable source to meet the increasing worldwide demand for fuel. However, efficient and simultaneous metabolism of all types of sugars in lignocellulosic hydrolysates by ethanol-producing strains is still a challenge. Results An engineered strain Escherichia coli B0013-2021HPA with regulated glucose utilization, which could use all monosaccharides in lignocellulosic hydrolysates except glucose for cell growth and glucose for ethanol production, was constructed. In E. coli B0013-2021HPA, pta-ackA, ldhA and pflB were deleted to block the formation of acetate, lactate and formate and additional three mutations at glk, ptsG and manZ generated to block the glucose uptake and catabolism, followed by the replacement of the wild-type frdA locus with the ptsG expression cassette under the control of the temperature-inducible λ pR and pL promoters, and the final introduction of pEtac-PA carrying Zymomonas mobilis pdc and adhB for the ethanol pathway. B0013-2021HPA was able to utilize almost all xylose, galactose and arabinose but not glucose for cell propagation at 34 °C and converted all sugars to ethanol at 42 °C under oxygen-limited fermentation conditions. Conclusions Engineered E. coli strain with regulated glucose utilization showed efficient metabolism of mixed sugars in lignocellulosic hydrolysates and thus higher productivity of ethanol production. Electronic supplementary material The online version of this article (10.1186/s12934-018-0915-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jinfeng Sun
- Center for Bioresource and Bioenergy, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,School of Life Science and Food Engineering, Huaiyin Institute of Technology, 1st East Meicheng Road, Huaian, 223003, China
| | - Kangming Tian
- Department of Biological Chemical Engineering, College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, TEDA, Tianjin, 300457, China
| | - Jie Wang
- Department of Biological Chemical Engineering, College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, TEDA, Tianjin, 300457, China
| | - Zixing Dong
- Department of Biological Chemical Engineering, College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, TEDA, Tianjin, 300457, China
| | - Xiaoguang Liu
- Department of Biological Chemical Engineering, College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, TEDA, Tianjin, 300457, China
| | - Kugenthiren Permaul
- Department of Biotechnology and Food Technology, Durban University of Technology, Durban, 4002, South Africa
| | - Suren Singh
- Department of Biotechnology and Food Technology, Durban University of Technology, Durban, 4002, South Africa
| | - Bernard A Prior
- Department of Microbiology, University of Stellenbosch, Matieland, 7602, South Africa
| | - Zhengxiang Wang
- Center for Bioresource and Bioenergy, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China. .,Department of Biological Chemical Engineering, College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, TEDA, Tianjin, 300457, China.
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Metabolic Engineering Strategies for Co-Utilization of Carbon Sources in Microbes. Bioengineering (Basel) 2016; 3:bioengineering3010010. [PMID: 28952572 PMCID: PMC5597168 DOI: 10.3390/bioengineering3010010] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 01/25/2016] [Indexed: 11/17/2022] Open
Abstract
Co-utilization of carbon sources in microbes is an important topic in metabolic engineering research. It is not only a way to reduce microbial production costs but also an attempt for either improving the yields of target products or decreasing the formation of byproducts. However, there are barriers in co-utilization of carbon sources in microbes, such as carbon catabolite repression. To overcome the barriers, different metabolic engineering strategies have been developed, such as inactivation of the phosphotransferase system and rewiring carbon assimilation pathways. This review summarizes the most recent developments of different strategies that support microbes to utilize two or more carbon sources simultaneously. The main content focuses on the co-utilization of glucose and pentoses, major sugars in lignocellulose.
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The transport and mediation mechanisms of the common sugars in Escherichia coli. Biotechnol Adv 2014; 32:905-19. [DOI: 10.1016/j.biotechadv.2014.04.009] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 03/23/2014] [Accepted: 04/18/2014] [Indexed: 11/17/2022]
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Wang J, Zhang Y, Chen Y, Lin M, Lin Z. Global regulator engineering significantly improvedEscherichia colitolerances toward inhibitors of lignocellulosic hydrolysates. Biotechnol Bioeng 2012; 109:3133-42. [DOI: 10.1002/bit.24574] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 04/06/2012] [Accepted: 05/30/2012] [Indexed: 01/09/2023]
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Park JM, Vinuselvi P, Lee SK. The mechanism of sugar-mediated catabolite repression of the propionate catabolic genes in Escherichia coli. Gene 2012; 504:116-21. [PMID: 22579471 DOI: 10.1016/j.gene.2012.04.074] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Revised: 02/22/2012] [Accepted: 04/22/2012] [Indexed: 01/30/2023]
Abstract
Carbon catabolite repression (CCR) is a well-known phenomenon that involves the preferential utilization of glucose as a carbon source. Cyclic adenosine monophosphate (cAMP) and the cAMP receptor protein (CRP) mediate CCR. Recently, a second CCR hierarchy that leads to the preferential consumption of arabinose over xylose, mediated by arabinose-bound AraC, has been identified. In this study, we report yet another CCR hierarchy that causes the preferential utilization of sugars (arabinose, galactose, glucose, mannose, and xylose) over a short-chain fatty acid (propionate). Expression of the propionate catabolic (prpBCDE) genes is down-regulated in the presence of these sugars. Sugar-mediated repression of the propionate catabolic genes is independent of sugar-specific regulators such as AraC and dependent on global regulators of sugar transport such as the cAMP-CRP complex and the Phosphotransferase System (PTS). Inhibition of the prpBCDE promoter is encountered during rapid sugar uptake and metabolism. This unique regulatory crosstalk between sugar metabolism and fatty acid metabolism may help provide new insights into CRP-dependent catabolite repression acting in conjunction with non-carbohydrate metabolism.
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Affiliation(s)
- Jung Min Park
- School of Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea
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Vinuselvi P, Lee SK. Engineered Escherichia coli capable of co-utilization of cellobiose and xylose. Enzyme Microb Technol 2011; 50:1-4. [PMID: 22133432 DOI: 10.1016/j.enzmictec.2011.10.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 09/22/2011] [Accepted: 10/12/2011] [Indexed: 12/13/2022]
Abstract
Natural ability to ferment the major sugars (glucose and xylose) of plant biomass is an advantageous feature of Escherichia coli in biofuel production. However, excess glucose completely inhibits xylose utilization in E. coli and decreases yield and productivity of fermentation due to sequential utilization of xylose after glucose. As an approach to overcome this drawback, E. coli MG1655 was engineered for simultaneous glucose (in the form of cellobiose) and xylose utilization by a combination of genetic and evolutionary engineering strategies. The recombinant E. coli was capable of utilizing approximately 6 g/L of cellobiose and 2 g/L of xylose in approximately 36 h, whereas wild-type E. coli was unable to utilize xylose completely in the presence of 6 g/L of glucose even after 75 hours. The engineered strain also co-utilized cellobiose with mannose or galactose; however, it was unable to metabolize cellobiose in the presence of arabinose and glucose. Successful cellobiose and xylose co-fermentation is a vital step for simultaneous saccharification and co-fermentation process and a promising step towards consolidated bioprocessing.
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Affiliation(s)
- Parisutham Vinuselvi
- School of Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea
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Pei XL, Wang QY, Li CL, Qiu XF, Xie KL, Huang LF, Wang AM, Zeng ZW, Xie T. Efficient Production of a Thermophilic 2-Deoxyribose-5-Phosphate Aldolase in Glucose-Limited Fed-Batch Cultivations of Escherichia coli by Continuous Lactose Induction Strategy. Appl Biochem Biotechnol 2011; 165:416-25. [DOI: 10.1007/s12010-011-9261-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Accepted: 04/04/2011] [Indexed: 11/25/2022]
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12
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Selective reduction of xylose to xylitol from a mixture of hemicellulosic sugars. Metab Eng 2010; 12:462-8. [DOI: 10.1016/j.ymben.2010.04.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 03/24/2010] [Accepted: 04/26/2010] [Indexed: 11/15/2022]
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13
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Khankal R, Chin JW, Ghosh D, Cirino PC. Transcriptional effects of CRP* expression in Escherichia coli. J Biol Eng 2009; 3:13. [PMID: 19703305 PMCID: PMC2743635 DOI: 10.1186/1754-1611-3-13] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Accepted: 08/24/2009] [Indexed: 01/31/2023] Open
Abstract
Background Escherichia coli exhibits diauxic growth in sugar mixtures due to CRP-mediated catabolite repression and inducer exclusion related to phosphotransferase system enzyme activity. Replacement of the native crp gene with a catabolite repression mutant (referred to as crp*) enables co-utilization of glucose and other sugars in E. coli. While previous studies have examined the effects of expressing CRP* mutants on the expression of specific catabolic genes, little is known about the global transcriptional effects of CRP* expression. In this study, we compare the transcriptome of E. coli W3110 (expressing wild-type CRP) to that of mutant strain PC05 (expressing CRP*) in the presence and absence of glucose. Results The glucose effect is significantly suppressed in strain PC05 relative to strain W3110. The expression levels of glucose-sensitive genes are generally not altered by glucose to the same extent in strain PCO5 as compared to W3110. Only 23 of the 80 genes showing significant differential expression in the presence of glucose for strain PC05 are present among the 418 genes believed to be directly regulated by CRP. Genes involved in central carbon metabolism (including several TCA cycle genes) and amino acid biosynthesis, as well as genes encoding nutrient transport systems are among those whose transcript levels are most significantly affected by CRP* expression. We present a detailed transcription analysis and relate these results to phenotypic differences between strains expressing wild-type CRP and CRP*. Notably, CRP* expression in the presence of glucose results in an elevated intracellular NADPH concentration and reduced NADH concentration relative to wild-type CRP. Meanwhile, a more drastic decrease in the NADPH/NADP+ ratio is observed for the case of CRP* expression in strains engineered to reduce xylose to xylitol via a heterologously expressed, NADPH-dependent xylose reductase. Altered expression levels of transhydrogenase and TCA cycle genes, among others, are consistent with these observations. Conclusion While the simplest model of CRP*-mediated gene expression assumes insensitivity to glucose (or cAMP), our results show that gene expression in the context of CRP* is very different from that of wild-type in the absence of glucose, and is influenced by the presence of glucose. Most of the transcription changes in response to CRP* expression are difficult to interpret in terms of possible systematic effects on metabolism. Elevated NADPH availability resulting from CRP* expression suggests potential biocatalytic applications of crp* strains that extend beyond relief of catabolite repression.
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Affiliation(s)
- Reza Khankal
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
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14
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Khankal R, Luziatelli F, Chin JW, Frei CS, Cirino PC. Comparison between Escherichia coli K-12 strains W3110 and MG1655 and wild-type E. coli B as platforms for xylitol production. Biotechnol Lett 2008; 30:1645-53. [DOI: 10.1007/s10529-008-9720-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Accepted: 03/17/2008] [Indexed: 01/21/2023]
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Karimova G, Dautin N, Ladant D. Interaction network among Escherichia coli membrane proteins involved in cell division as revealed by bacterial two-hybrid analysis. J Bacteriol 2005; 187:2233-43. [PMID: 15774864 PMCID: PMC1065216 DOI: 10.1128/jb.187.7.2233-2243.2005] [Citation(s) in RCA: 386] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Formation of the Escherichia coli division septum is catalyzed by a number of essential proteins (named Fts) that assemble into a ring-like structure at the future division site. Several of these Fts proteins are intrinsic transmembrane proteins whose functions are largely unknown. Although these proteins appear to be recruited to the division site in a hierarchical order, the molecular interactions underlying the assembly of the cell division machinery remain mostly unspecified. In the present study, we used a bacterial two-hybrid system based on interaction-mediated reconstitution of a cyclic AMP (cAMP) signaling cascade to unravel the molecular basis of septum assembly by analyzing the protein interaction network among E. coli cell division proteins. Our results indicate that the Fts proteins are connected to one another through multiple interactions. A deletion mapping analysis carried out with two of these proteins, FtsQ and FtsI, revealed that different regions of the polypeptides are involved in their associations with their partners. Furthermore, we showed that the association between two Fts hybrid proteins could be modulated by the coexpression of a third Fts partner. Altogether, these data suggest that the cell division machinery assembly is driven by the cooperative association among the different Fts proteins to form a dynamic multiprotein structure at the septum site. In addition, our study shows that the cAMP-based two-hybrid system is particularly appropriate for analyzing molecular interactions between membrane proteins.
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Affiliation(s)
- Gouzel Karimova
- Unité de Biochimie des Interactions Macromoléculaires, Institut Pasteur, 75724 Paris, Cedex 15, France.
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