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Rom JS, Le Breton Y, Islam E, Belew AT, El-Sayed NM, McIver KS. Loss of rpoE Encoding the δ-Factor of RNA Polymerase Impacts Pathophysiology of the Streptococcus pyogenes M1T1 Strain 5448. Microorganisms 2022; 10:microorganisms10081686. [PMID: 36014103 PMCID: PMC9412562 DOI: 10.3390/microorganisms10081686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/08/2022] [Accepted: 08/19/2022] [Indexed: 12/01/2022] Open
Abstract
Streptococcus pyogenes, also known as the Group A Streptococcus (GAS), is a Gram-positive bacterial pathogen of major clinical significance. Despite remaining relatively susceptible to conventional antimicrobial therapeutics, GAS still causes millions of infections and hundreds of thousands of deaths each year worldwide. Thus, a need for prophylactic and therapeutic interventions for GAS is in great demand. In this study, we investigated the importance of the gene encoding the delta (δ) subunit of the GAS RNA polymerase, rpoE, for its impact on virulence during skin and soft-tissue infection. A defined 5448 mutant with an insertionally-inactivated rpoE gene was defective for survival in whole human blood and was attenuated for both disseminated lethality and lesion size upon mono-culture infection in mouse soft tissue. Furthermore, the mutant had reduced competitive fitness when co-infected with wild type (WT) 5448 in the mouse model. We were unable to attribute this attenuation to any observable growth defect, although colony size and the ability to grow at higher temperatures were both affected when grown with nutrient-rich THY media. RNA-seq of GAS grown in THY to late log phase found that mutation of rpoE significantly impacted (>2-fold) the expression of 429 total genes (205 upregulated, 224 downregulated), including multiple virulence and “housekeeping” genes. The arc operon encoding the arginine deiminase (ADI) pathway was the most upregulated in the rpoE mutant and this could be confirmed phenotypically. Taken together, these findings demonstrate that the delta (δ) subunit of RNA polymerase is vital in GAS gene expression and virulence.
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Zhang Y, Higgins CB, Van Tine BA, Bomalaski JS, DeBosch BJ. Pegylated arginine deiminase drives arginine turnover and systemic autophagy to dictate energy metabolism. Cell Rep Med 2022; 3:100498. [PMID: 35106510 PMCID: PMC8784773 DOI: 10.1016/j.xcrm.2021.100498] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 11/16/2021] [Accepted: 12/16/2021] [Indexed: 12/30/2022]
Abstract
Obesity is a multi-systemic disorder of energy balance. Despite intense investigation, the determinants of energy homeostasis remain incompletely understood, and efficacious treatments against obesity and its complications are lacking. Here, we demonstrate that conferred arginine iminohydrolysis by the bacterial virulence factor and arginine deiminase, arcA, promotes mammalian energy expenditure and insulin sensitivity and reverses dyslipidemia, hepatic steatosis, and inflammation in obese mice. Extending this, pharmacological arginine catabolism via pegylated arginine deiminase (ADI-PEG 20) recapitulates these metabolic effects in dietary and genetically obese models. These effects require hepatic and whole-body expression of the autophagy complex protein BECN1 and hepatocyte-specific FGF21 secretion. Single-cell ATAC sequencing further reveals BECN1-dependent hepatocyte chromatin accessibility changes in response to ADI-PEG 20. The data thus reveal an unexpected therapeutic utility for arginine catabolism in modulating energy metabolism by activating systemic autophagy, which is now exploitable through readily available pharmacotherapy.
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Affiliation(s)
- Yiming Zhang
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Cassandra B. Higgins
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Brian A. Van Tine
- Division of Medical Oncology, Washington University School of Medicine, St. Louis, MO 63108, USA
- Division of Pediatric Hematology/Oncology, St. Louis Children’s Hospital, St. Louis, MO 63108, USA
- Siteman Cancer Center, St. Louis, MO 63108, USA
| | | | - Brian J. DeBosch
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Cell Biology & Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA
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Zhao X, Zeng X, Dai Q, Hou Y, Zhu D, Wang M, Jia R, Chen S, Liu M, Yang Q, Wu Y, Zhang S, Huang J, Ou X, Mao S, Gao Q, Zhang L, Liu Y, Yu Y, Cheng A. Immunogenicity and protection efficacy of a Salmonella enterica serovar Typhimurium fnr, arcA and fliC mutant. Vaccine 2020; 39:588-595. [PMID: 33341307 DOI: 10.1016/j.vaccine.2020.12.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 11/05/2020] [Accepted: 12/01/2020] [Indexed: 01/17/2023]
Abstract
Salmonella enterica serovar Typhimurium is a major food-borne pathogen that can cause self-limited gastroenteritis or life-threatening invasive diseases in humans. There is no licensed S. Typhimurium vaccine for humans to date. In this study, we attempted to construct a live attenuated vaccine strain of S. Typhimurium based on three genes, namely, the two global regulator genes fnr and arcA and the flagellin subunit gene fliC. The S. Typhimurium three-gene mutant, named SLT39 (ΔfnrΔarcAΔfliC), exhibited a high level of attenuation with a colonization defect in mouse tissues and approximately 104-fold decreased virulence compared with that of the wild-type strain. To evaluate the immunogenicity and protection efficacy of STL39, mice were inoculated twice with a dose of 107 CFU or 108 CFU at a 28-day interval, and the immunized mice were challenged with a lethal dose of the wild-type S. Typhimurium strain one month post second immunization. Compared with mock immunization, SLT39 immunization with either dose elicited significant serum total IgG, IgG1 and IgG2a and faecal IgA responses against inactivated S. Typhimurium antigens at a comparable level post second immunization, whereas the 108 CFU group induced higher levels of duodenal and caecal IgA than the 107 CFU group. Furthermore, the bacterial loads in mouse tissues, including Peyer's patches, spleen and liver, significantly decreased in the two SLT39 immunization groups compared to those in the control group post challenge. Additionally, all mice in the SLT39 (108 CFU) group and 80% of the mice in the SLT39 (107 CFU) group survived the lethal challenge, suggesting full protection and 80% protection efficacy, respectively. Thus, the S. Typhimurium fnr, arcA and fliC mutant proved to be a potential attenuated live vaccine candidate for prevention of homologous infection.
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Affiliation(s)
- Xinxin Zhao
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Xiaoli Zeng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Qinlong Dai
- Liziping National Nature Reserve, Shimian, Sichuan, China
| | - Yulong Hou
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Dekang Zhu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Mingshu Wang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Renyong Jia
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Shun Chen
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Mafeng Liu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Qiao Yang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Ying Wu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Shaqiu Zhang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Juan Huang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Xumin Ou
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Sai Mao
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Qun Gao
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Ling Zhang
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Yunya Liu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Yanling Yu
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Anchun Cheng
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Hadyeh E, Azmi K, Seir RA, Abdellatief I, Abdeen Z. Molecular Characterization of Methicillin Resistant Staphylococcus aureus in West Bank-Palestine. Front Public Health 2019; 7:130. [PMID: 31192182 PMCID: PMC6549579 DOI: 10.3389/fpubh.2019.00130] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 05/08/2019] [Indexed: 11/16/2022] Open
Abstract
Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a public health threat and a major cause of hospital-acquired and community-acquired infections. This study aimed to investigate the genetic diversity of MRSA isolates from 2015 to 2017 and to characterize the major MRSA clones and anti-biogram trends in Palestine. Methodology: Isolates were obtained from 112 patients admitted to different hospitals of West Bank and East Jerusalem, originating from different clinical sources. Antibiotic susceptibility patterns, staphylococcal chromosomal cassette mec (SCCmec) typing, and Staphylococcus aureus protein A (spa) typing were determined. Also, a panel of toxin genes and virulence factors was studied, including: Panton-Valentine Leukocidin (PVL), ACME-arcA, Toxic Shock Syndrome Toxin-1 (TSST-1), and Exfoliative Toxin A (ETA). Results: Of the 112 confirmed MRSA isolates, 100% were resistant to all β-lactam antibiotics. Resistance rates to other non- β-lactam classes were as the following: 18.8% were resistant to trimethoprim-sulfamethoxazole, 23.2% were resistant to gentamicin, 34.8% to clindamycin, 39.3% to ciprofloxacin, and 63.4% to erythromycin. All MRSA isolates were susceptible to vancomycin (100%). Of all isolates, 32 isolates (28.6%) were multidrug- resistant (MDR). The majority of the isolates were identified as SCCmec type IV (86.6%). The molecular typing identified 29 spa types representing 12 MLST-clonal complexes (CC). The most prevalent spa types were: spa type t386 (CC1)/(12.5%), spa type t044 (CC80)/(10.7%), spa type t008 (CC8)/(10.7%), and spa type t223 (CC22)/(9.8%). PVL toxin gene was detected in (29.5%) of all isolates, while ACME-arcA gene was present in 18.8% of all isolates and 23.2% had the TSST-1 gene. The two most common spa types among the TSST-1positive isolates were the spa type t223 (CC22)/(Gaza clone) and the spa type t021 (CC30)/(South West Pacific clone). All isolates with the spa type t991 were ETA positive (5.4%). USA-300 clone (spa type t008, positive for PVL toxin gene and ACME-arcA genes) was found in nine isolates (8.0%). Conclusions: Our results provide insights into the epidemiology of MRSA strains in Palestine. We report a high diversity of MRSA strains among hospitals in Palestine, with frequent SCCmec type IV carriage. The four prominent clones detected were: t386-IV/ CC1, the European clone (t044/CC80), Gaza clone (t223/CC22), and the USA-300 clone (t008/CC8).
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Affiliation(s)
- Etaf Hadyeh
- Al-Quds Public Health Society, Jerusalem, Palestine.,Department of Medical Lab Sciences, Faculty of Health Professions, Jerusalem, Palestine
| | - Kifaya Azmi
- Al-Quds Public Health Society, Jerusalem, Palestine.,Faculty of Medicine, Al-Quds Nutrition and Health Research Institute, Al-Quds University, Jerusalem, Palestine.,Biochemistry and Molecular Biology Department, Faculty of Medicine, Al-Quds University, Jerusalem, Palestine
| | - Rania Abu Seir
- Department of Medical Lab Sciences, Faculty of Health Professions, Jerusalem, Palestine
| | - Inas Abdellatief
- Laboratory Department of Al-Makassed Charitable Hospital, Jerusalem, Palestine
| | - Ziad Abdeen
- Al-Quds Public Health Society, Jerusalem, Palestine.,Faculty of Medicine, Al-Quds Nutrition and Health Research Institute, Al-Quds University, Jerusalem, Palestine
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Liu M, Ding Y, Chen H, Zhao Z, Liu H, Xian M, Zhao G. Improving the production of acetyl-CoA-derived chemicals in Escherichia coli BL21(DE3) through iclR and arcA deletion. BMC Microbiol 2017; 17:10. [PMID: 28061812 PMCID: PMC5219675 DOI: 10.1186/s12866-016-0913-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 12/13/2016] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Acetyl-CoA-derived chemicals are suitable for multiple applications in many industries. The bio-production of these chemicals has become imperative owing to the economic and environmental problems. However, acetate overflow is the major drawback for acetyl-CoA-derived chemicals production. Approaches for overcoming acetate overflow may be beneficial for the production of acetyl-CoA-derived chemicals. RESULTS In this study, a transcriptional regulator iclR was knocked out in E.coli BL21(DE3) to overcome acetate overflow and improve the chemicals production. Two important acetyl-CoA-derived chemicals, phloroglucinol (PG) and 3-hydroxypropionate (3HP) were used to evaluate it. It is revealed that knockout of iclR significantly increased expressions of aceBAK operon. The cell yields and glucose utilization efficiencies were higher than those of control strains. The acetate concentrations were decreased by more than 50% and the productions of PG and 3HP were increased more than twice in iclR mutants. The effects of iclR knockout on cell physiology, cell metabolism and production of acetyl-CoA-derived chemicals were similar to those of arcA knockout in our previous study. However, the arcA-iclR double mutants couldn't gain higher productions of PG and 3HP. The mechanisms are unclear and needed to be resolved in future. CONCLUSIONS Knockout of iclR significantly increased gene expression of aceBAK operon and concomitantly activated glyoxylate pathway. This genetic modification may be a good way to overcome acetate overflow, and improve the production of a wide range of acetyl-CoA-derived chemicals.
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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
| | - Yamei Ding
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Hailin Chen
- 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
| | - 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
| | - Huizhou Liu
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
| | - Mo Xian
- 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. .,Randian Technology Company Limited, Tianjin, 300457, China.
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Scheel RA, Ji L, Lundgren BR, Nomura CT. Enhancing poly(3-hydroxyalkanoate) production in Escherichia coli by the removal of the regulatory gene arcA. AMB Express 2016; 6:120. [PMID: 27878786 PMCID: PMC5120623 DOI: 10.1186/s13568-016-0291-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 11/09/2016] [Indexed: 11/18/2022] Open
Abstract
Recombinant Escherichia coli is a desirable platform for the production of many biological compounds including poly(3-hydroxyalkanoates), a class of naturally occurring biodegradable polyesters with promising biomedical and material applications. Although the controlled production of desirable polymers is possible with the utilization of fatty acid feedstocks, a central challenge to this biosynthetic route is the improvement of the relatively low polymer yield, a necessary factor of decreasing the production costs. In this study we sought to address this challenge by deleting arcA and ompR, two global regulators with the capacity to inhibit the uptake and activation of exogenous fatty acids. We found that polymer yields in a ΔarcA mutant increased significantly with respect to the parental strain. In the parental strain, PHV yields were very low but improved 64-fold in the ΔarcA mutant (1.92-124 mg L-1) The ΔarcA mutant also allowed for modest increases in some medium chain length polymer yields, while weight average molecular weights improved by approximately 1.5-fold to 12-fold depending on the fatty acid substrate utilized. These results were supported by an analysis of differential gene expression, which showed that the key genes (fadD, fadL, and fadE) encoding fatty acid degradation enzymes were all upregulated by 2-, 10-, and 31-fold in an ΔarcA mutant, respectively. Additionally, the short chain length fatty acid uptake genes atoA, atoE and atoD were upregulated by 103-, 119-, and 303-fold respectively, though these values are somewhat inflated due to low expression in the parental strain. Overall, this study demonstrates that arcA is an important target to improve PHA production from fatty acids.
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Affiliation(s)
- Ryan A. Scheel
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY 13210 USA
| | - Liyuan Ji
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY 13210 USA
| | - Benjamin R. Lundgren
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY 13210 USA
| | - Christopher T. Nomura
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY 13210 USA
- Center for Applied Microbiology, State University of New York College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY 13210 USA
- Hubei Collaborative Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan, 430062 China
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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