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Yang X, Yang J, Huang H, Yan X, Li X, Lin Z. Achieving robust synthetic tolerance in industrial E. coli through negative auto-regulation of a DsrA-Hfq module. Synth Syst Biotechnol 2024; 9:462-469. [PMID: 38634002 PMCID: PMC11021974 DOI: 10.1016/j.synbio.2024.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/29/2024] [Accepted: 04/06/2024] [Indexed: 04/19/2024] Open
Abstract
In industrial fermentation processes, microorganisms often encounter acid stress, which significantly impact their productivity. This study focused on the acid-resistant module composed of small RNA (sRNA) DsrA and the sRNA chaperone Hfq. Our previous study had shown that this module improved the cell growth of Escherichia coli MG1655 at low pH, but failed to obtain this desired phenotype in industrial strains. Here, we performed a quantitative analysis of DsrA-Hfq module to determine the optimal expression mode. We then assessed the potential of the CymR-based negative auto-regulation (NAR) circuit for industrial application, under different media, strains and pH levels. Growth assay at pH 4.5 revealed that NAR-05D04H circuit was the best acid-resistant circuit to improve the cell growth of E. coli MG1655. This circuit was robust and worked well in the industrial lysine-producing strain E. coli SCEcL3 at a starting pH of 6.8 and without pH control, resulting in a 250 % increase in lysine titer and comparable biomass in shaking flask fermentation compared to the parent strain. This study showed the practical application of NAR circuit in regulating DsrA-Hfq module, effectively and robustly improving the acid tolerance of industrial strains, which provides a new approach for breeding industrial strains with tolerance phenotype.
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Affiliation(s)
- Xiaofeng Yang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Jingduan Yang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Haozheng Huang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Xiaofang Yan
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Xiaofan Li
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Zhanglin Lin
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
- School of Biomedicine, Guangdong University of Technology, Guangzhou 510006, China
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2
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Li Z, Li S, Chen L, Sun T, Zhang W. Fast-growing cyanobacterial chassis for synthetic biology application. Crit Rev Biotechnol 2024; 44:414-428. [PMID: 36842999 DOI: 10.1080/07388551.2023.2166455] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 11/19/2022] [Accepted: 12/28/2022] [Indexed: 02/28/2023]
Abstract
Carbon neutrality by 2050 has become one of the most urgent challenges the world faces today. To address the issue, it is necessary to develop and promote new technologies related with CO2 recycling. Cyanobacteria are the only prokaryotes performing oxygenic photosynthesis, capable of fixing CO2 into biomass under sunlight and serving as one of the most important primary producers on earth. Notably, recent progress on synthetic biology has led to utilizing model cyanobacteria such as Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942 as chassis for "light-driven autotrophic cell factories" to produce several dozens of biofuels and various fine chemicals directly from CO2. However, due to the slow growth rate and low biomass accumulation in the current chassis, the productivity for most products is still lower than the threshold necessary for large-scale commercial application, raising the importance of developing high-efficiency cyanobacterial chassis with fast growth and/or higher biomass accumulation capabilities. In this article, we critically reviewed recent progresses on identification, systems biology analysis, and engineering of fast-growing cyanobacterial chassis. Specifically, fast-growing cyanobacteria identified in recent years, such as S. elongatus UTEX 2973, S. elongatus PCC 11801, S. elongatus PCC 11802 and Synechococcus sp. PCC 11901 was comparatively analyzed. In addition, the progresses on their recent application in converting CO2 into chemicals, and genetic toolboxes developed for these new cyanobacterial chassis were discussed. Finally, the article provides insights into future challenges and perspectives on the synthetic biology application of cyanobacterial chassis.
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Affiliation(s)
- Zhixiang Li
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, P.R. China
| | - Shubin Li
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, P.R. China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, P.R. China
| | - Tao Sun
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, P.R. China
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, P.R. China
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, P.R. China
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, P.R. China
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3
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Ko SC, Woo HM. CRISPR-dCas13a system for programmable small RNAs and polycistronic mRNA repression in bacteria. Nucleic Acids Res 2024; 52:492-506. [PMID: 38015471 PMCID: PMC10783499 DOI: 10.1093/nar/gkad1130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 11/07/2023] [Accepted: 11/09/2023] [Indexed: 11/29/2023] Open
Abstract
Bacterial small RNAs (sRNAs) function in post-transcriptional regulatory responses to environmental changes. However, the lack of eukaryotic RNA interference-like machinery in bacteria has limited the systematic engineering of RNA repression. Here, we report the development of clustered regularly interspaced short palindromic repeats (CRISPR)-guided dead CRIPSR-associated protein 13a (dCas13a) ribonucleoprotein that utilizes programmable CRISPR RNAs (crRNAs) to repress trans-acting and cis-acting sRNA as the target, altering regulatory mechanisms and stress-related phenotypes. In addition, we implemented a modular loop engineering of the crRNA to promote modular repression of the target gene with 92% knockdown efficiency and a single base-pair mismatch specificity. With the engineered crRNAs, we achieved targetable single-gene repression in the polycistronic operon. For metabolic application, 102 crRNAs were constructed in the biofoundry and used for screening novel knockdown sRNA targets to improve lycopene (colored antioxidant) production in Escherichia coli. The CRISPR-dCas13a system will assist as a valuable systematic tool for the discovery of novel sRNAs and the fine-tuning of bacterial RNA repression in both scientific and industrial applications.
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Affiliation(s)
- Sung Cheon Ko
- Department of Food Science and Biotechnology, Sungkyunkwan University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea
- BioFoundry Research Center, Institute of Biotechnology and Bioengineering, Sungkyunkwan University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea
| | - Han Min Woo
- Department of Food Science and Biotechnology, Sungkyunkwan University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea
- BioFoundry Research Center, Institute of Biotechnology and Bioengineering, Sungkyunkwan University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea
- Department of MetaBioHealth, Sungkyunkwan University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea
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4
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Zhang Y, Pan L, Zhang Y, Wang K, Wang L, Zhang H, Zhang J, Chen X. Understanding the Streptomyces albulus response to low-pH stress at the interface of physiology and transcriptomics. Appl Microbiol Biotechnol 2023; 107:2611-2626. [PMID: 36882645 DOI: 10.1007/s00253-023-12449-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 02/15/2023] [Accepted: 02/21/2023] [Indexed: 03/09/2023]
Abstract
Streptomyces albulus is a well-established cell factory for ε-poly-L-lysine (ε-PL) production. It has been reported that ε-PL biosynthesis is strictly regulated by pH and that ε-PL can accumulate at approximately pH 4.0, which is outside of the general pH range for natural product production by Streptomyces species. However, how S. albulus responds to low pH is not clear. In this study, we attempted to explore the response of S. albulus to low-pH stress at the physiological and global gene transcription levels. At the physiological level, S. albulus maintained intracellular pH homeostasis at ~pH 7.5, increased the unsaturated fatty acid ratio, extended the fatty acid chain length, enhanced ATP accumulation, increased H+-ATPase activity, and accumulated the basic amino acids L-lysine and L-arginine. At the global gene transcription level, carbohydrate metabolism, oxidative phosphorylation, macromolecule protection and repair, and the acid tolerance system were found to be involved in combating low-pH stress. Finally, we preliminarily evaluated the effect of the acid tolerance system and cell membrane fatty acid synthesis on low-pH tolerance via gene manipulation. This work provides new insight into the adaptation mechanism of Streptomyces to low-pH stress and a new opportunity for constructing robust S. albulus strains for ε-PL production. KEY POINTS: • S. albulus consistently remained pH i at ~7.4 regardless of the environmental pH. • S. albulus combats low-pH stress by modulating lipid composition of cell membrane. • Overexpression of cfa in S. albulus could improve low-pH tolerance and ɛ-PL titer.
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Affiliation(s)
- Yulin Zhang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi214122, Wuxi, Jiangsu, China
| | - Long Pan
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi214122, Wuxi, Jiangsu, China
- School of Biological Engineering, Henan University of Technology, Zhengzhou, 450001, China
| | - Yue Zhang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi214122, Wuxi, Jiangsu, China
| | - Kaifang Wang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi214122, Wuxi, Jiangsu, China
| | - Liang Wang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi214122, Wuxi, Jiangsu, China
| | - Hongjian Zhang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi214122, Wuxi, Jiangsu, China
| | - Jianhua Zhang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi214122, Wuxi, Jiangsu, China
| | - Xusheng Chen
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi214122, Wuxi, Jiangsu, China.
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Revealing novel synergistic defense and acid tolerant performance of Escherichia coli in response to organic acid stimulation. Appl Microbiol Biotechnol 2022; 106:7577-7594. [DOI: 10.1007/s00253-022-12241-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 10/04/2022] [Accepted: 10/12/2022] [Indexed: 11/06/2022]
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6
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Smirnov A. How global RNA-binding proteins coordinate the behaviour of RNA regulons: an information approach. Comput Struct Biotechnol J 2022; 20:6317-6338. [DOI: 10.1016/j.csbj.2022.11.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/07/2022] [Accepted: 11/07/2022] [Indexed: 11/13/2022] Open
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7
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The Molecular Toolset and Techniques Required to Build Cyanobacterial Cell Factories. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2022. [DOI: 10.1007/10_2022_210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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8
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Siddiqui N, Gupta AK, Dutta T. PhoP induces RyjB expression under acid stress in Escherichia coli. J Biochem 2021; 171:277-285. [PMID: 34967409 PMCID: PMC9077410 DOI: 10.1093/jb/mvab142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 12/07/2021] [Indexed: 01/01/2023] Open
Abstract
Bacterial small RNAs (sRNAs) play a pivotal role in post-transcriptional regulation of gene expression and participate in many physiological circuits. An ~80-nt-long RyjB was earlier identified as a novel sRNA, which appeared to be accumulated in all phases of growth in Escherichia coli. We have taken a comprehensive approach in the current study to understand the regulation of ryjB expression under normal and pH stress conditions. RpoS was not necessary for ryjB expression neither at normal condition nor under acid stress. Hfq also emerged to be unnecessary for RyjB accumulation. Interestingly, RyjB was detected as a novel acid stress induced sRNA. A DNA binding protein PhoP, a component of PhoP/Q regulon, was found to regulate ryjB expression at low pH, as the elimination of phoP allele in the chromosome exhibited a basal level of RyjB expression under acid stress. Ectopic expression of PhoP in ΔphoP cells restored the overabundance of RyjB in the cell. Overexpression of RyjB increased the abundance of sgcA transcripts, with which RyjB shares a 4-nt overlap. The current study increases our knowledge substantially regarding the regulation of ryjB expression in E. coli cell.
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Affiliation(s)
- Namra Siddiqui
- RNA Biology Laboratory, Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Amit Kumar Gupta
- Center for Cancer Research, National Cancer Institute, Frederick, MD 21702-1201, USA
| | - Tanmay Dutta
- RNA Biology Laboratory, MS 731, Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India. Tel.: +91-11-2659-1508, Fax: +91-11-2658-1102,
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9
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A Shift to Human Body Temperature (37°C) Rapidly Reprograms Multiple Adaptive Responses in Escherichia coli That Would Facilitate Niche Survival and Colonization. J Bacteriol 2021; 203:e0036321. [PMID: 34516284 PMCID: PMC8544407 DOI: 10.1128/jb.00363-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
One of the first environmental cues sensed by a microbe as it enters a human host is an upshift in temperature to 37°C. In this dynamic time point analysis, we demonstrate that this environmental transition rapidly signals a multitude of gene expression changes in Escherichia coli. Bacteria grown at 23°C under aerobic conditions were shifted to 37°C, and mRNA expression was measured at time points after the shift to 37°C (t = 0.5, 1, and 4 h). The first hour is characterized by a transient shift to anaerobic respiration strategies and stress responses, particularly acid resistance, indicating that temperature serves as a sentinel cue to predict and prepare for various niches within the host. The temperature effects on a subset of stress response genes were shown to be mediated by RpoS and directly correlated with RpoS, DsrA, and RprA levels, and increased acid resistance was observed that was dependent on 23°C growth and RpoS. By 4 h, gene expression shifted to aerobic respiration pathways and decreased stress responses, coupled with increases in genes associated with biosynthesis (amino acid and nucleotides), iron uptake, and host defense. ompT, a gene that confers resistance to antimicrobial peptides, was highly thermoregulated, with a pattern conserved in enteropathogenic and uropathogenic E. coli strains. An immediate decrease in curli gene expression concomitant with an increase in flagellar gene expression implicates temperature in this developmental decision. Together, our studies demonstrate that temperature signals a reprogramming of gene expression immediately upon an upshift that may predict, prepare, and benefit the survival of the bacterium within the host. IMPORTANCE As one of the first cues sensed by the microbe upon entry into a human host, understanding how bacteria like E. coli modulate gene expression in response to temperature improves our understanding of how bacteria immediately initiate responses beneficial for survival and colonization. For pathogens, understanding the various pathways of thermal regulation could yield valuable targets for anti-infective chemotherapeutic drugs or disinfection measures. In addition, our data provide a dynamic examination of the RpoS stress response, providing genome-wide support for how temperature impacts RpoS through changes in RpoS stability and modulation by small regulatory RNAs.
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10
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The challenges and prospects of Escherichia coli as an organic acid production host under acid stress. Appl Microbiol Biotechnol 2021; 105:8091-8107. [PMID: 34617140 DOI: 10.1007/s00253-021-11577-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 09/07/2021] [Accepted: 09/08/2021] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Organic acids have a wide range of applications and have attracted the attention of many industries, and their large-scale applications have led fermentation production to low-cost development. Among them, the microbial fermentation method, especially using Escherichia coli as the production host, has the advantages of fast growth and low energy consumption, and has gradually shown better advantages and prospects in organic acid fermentation production. IMPORTANCE However, when the opportunity comes, the acidified environment caused by the acid products accumulated during the fermentation process also challenges E. coli. The acid sensitivity of E. coli is a core problem that needs to be solved urgently. The addition of neutralizers in traditional operations led to the emergence of osmotic stress inadvertently, the addition of strong acid substances to recover products in the salt state not only increases production costs, but the discharged sewage is also harmful to the environment. ELABORATION This article summarizes the current status of the application of E. coli in the production of organic acids, and based on the impact of acid stress on the physiological state of cells and the impact of industrial production profits, put forward some new conjectures that can make up for the deficiencies in existing research and application. IMPLICATION At this point, the diversified transformation of E. coli has become a chassis microbe that is more suitable for industrial fermentation, enhancing industrial application value. KEY POINTS • E. coli is a potential host for high value-added organic acids production. • Classify the damage mechanism and coping strategies of E. coli when stimulated by acid molecules. • Multi-dimensional expansion tools are needed to create acid-resistant E. coli chassis.
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11
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Engineering of the Small Noncoding RNA (sRNA) DsrA Together with the sRNA Chaperone Hfq Enhances the Acid Tolerance of Escherichia coli. Appl Environ Microbiol 2021; 87:AEM.02923-20. [PMID: 33674434 DOI: 10.1128/aem.02923-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/21/2021] [Indexed: 11/20/2022] Open
Abstract
Acid tolerance of microorganisms is a desirable phenotype for many industrial fermentation applications. In Escherichia coli, the stress response sigma factor RpoS is a promising target for engineering acid-tolerant phenotypes. However, the simple overexpression of RpoS alone is insufficient to confer these phenotypes. In this study, we show that the simultaneous overexpression of the noncoding small RNA (sRNA) DsrA and the sRNA chaperone Hfq, which act as RpoS activators, significantly increased acid tolerance in terms of cell growth under modest acidic pH, as well as cell survival upon extreme acid shock. Directed evolution of the DsrA-Hfq module further improved the acid tolerance, with the best mutants showing a 51 to 72% increase in growth performance at pH 4.5 compared with the starting strain, MG1655. Further analyses found that the improved acid tolerance of these DsrA-Hfq strains coincided with activation of genes associated with proton-consuming acid resistance system 2 (AR2), protein chaperone HdeB, and reactive oxygen species (ROS) removal in the exponential phase. This study illustrated that the fine-tuning of sRNAs and their chaperones can be a novel strategy for improving the acid tolerance of E. coli IMPORTANCE Many of the traditional studies on bacterial acid tolerance generally focused on improving cell survival under extreme-pH conditions, but cell growth under less harsh acidic conditions is more relevant to industrial applications. Under normal conditions, the general stress response sigma factor RpoS is maintained at low levels in the growth phase through a number of mechanisms. This study showed that RpoS can be activated prior to the stationary phase via engineering its activators, the sRNA DsrA and the sRNA chaperone Hfq, resulting in significantly improved cell growth at modest acidic pH. This work suggests that the sigma factors and likely other transcription factors can be retuned or retimed by manipulating the respective regulatory sRNAs along with the sufficient supply of the respective sRNA chaperones (i.e., Hfq). This provides a novel avenue for strain engineering of microbes.
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12
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Martin-Pascual M, Batianis C, Bruinsma L, Asin-Garcia E, Garcia-Morales L, Weusthuis RA, van Kranenburg R, Martins Dos Santos VAP. A navigation guide of synthetic biology tools for Pseudomonas putida. Biotechnol Adv 2021; 49:107732. [PMID: 33785373 DOI: 10.1016/j.biotechadv.2021.107732] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 03/12/2021] [Accepted: 03/18/2021] [Indexed: 12/12/2022]
Abstract
Pseudomonas putida is a microbial chassis of huge potential for industrial and environmental biotechnology, owing to its remarkable metabolic versatility and ability to sustain difficult redox reactions and operational stresses, among other attractive characteristics. A wealth of genetic and in silico tools have been developed to enable the unravelling of its physiology and improvement of its performance. However, the rise of this microbe as a promising platform for biotechnological applications has resulted in diversification of tools and methods rather than standardization and convergence. As a consequence, multiple tools for the same purpose have been generated, whilst most of them have not been embraced by the scientific community, which has led to compartmentalization and inefficient use of resources. Inspired by this and by the substantial increase in popularity of P. putida, we aim herein to bring together and assess all currently available (wet and dry) synthetic biology tools specific for this microbe, focusing on the last 5 years. We provide information on the principles, functionality, advantages and limitations, with special focus on their use in metabolic engineering. Additionally, we compare the tool portfolio for P. putida with those for other bacterial chassis and discuss potential future directions for tool development. Therefore, this review is intended as a reference guide for experts and new 'users' of this promising chassis.
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Affiliation(s)
- Maria Martin-Pascual
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Wageningen 6708 WE, The Netherlands
| | - Christos Batianis
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Wageningen 6708 WE, The Netherlands
| | - Lyon Bruinsma
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Wageningen 6708 WE, The Netherlands
| | - Enrique Asin-Garcia
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Wageningen 6708 WE, The Netherlands
| | - Luis Garcia-Morales
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Wageningen 6708 WE, The Netherlands
| | - Ruud A Weusthuis
- Bioprocess Engineering, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Richard van Kranenburg
- Corbion, Gorinchem 4206 AC, The Netherlands; Laboratory of Microbiology, Wageningen University & Research, Wageningen 6708 WE, the Netherlands
| | - Vitor A P Martins Dos Santos
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Wageningen 6708 WE, The Netherlands; LifeGlimmer GmbH, Berlin 12163, Germany.
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13
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Choi O, Kang B, Lee Y, Lee Y, Kim J. Pantoea ananatis carotenoid production confers toxoflavin tolerance and is regulated by Hfq-controlled quorum sensing. Microbiologyopen 2020; 10:e1143. [PMID: 33269542 PMCID: PMC7883899 DOI: 10.1002/mbo3.1143] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/09/2020] [Accepted: 11/19/2020] [Indexed: 02/06/2023] Open
Abstract
Carotenoids are widely used in functional foods, cosmetics, and health supplements, and their importance and scope of use are continuously expanding. Here, we characterized carotenoid biosynthetic genes of the plant‐pathogenic bacterium Pantoea ananatis, which carries a carotenoid biosynthetic gene cluster (including crtE, X, Y, I, B, and Z) on a plasmid. Reverse transcription–polymerase chain reaction (RT‐PCR) analysis revealed that the crtEXYIB gene cluster is transcribed as a single transcript and crtZ is independently transcribed in the opposite direction. Using splicing by overlap extension with polymerase chain reaction (SOE by PCR) based on asymmetric amplification, we reassembled crtE–B, crtE–B–I, and crtE–B–I–Y. High‐performance liquid chromatography confirmed that Escherichia coli expressing the reassembled crtE–B, crtE–B–I, and crtE–B–I–Y operons produced phytoene, lycopene, and β‐carotene, respectively. We found that the carotenoids conferred tolerance to UV radiation and toxoflavin. Pantoea ananatis shares rice environments with the toxoflavin producer Burkholderia glumae and is considered to be the first reported example of producing and using carotenoids to withstand toxoflavin. We confirmed that carotenoid production by P. ananatis depends on RpoS, which is positively regulated by Hfq/ArcZ and negatively regulated by ClpP, similar to an important regulatory network of E. coli (HfqArcZ →RpoS Ͱ ClpXP). We also demonstrated that Hfq‐controlled quorum signaling de‐represses EanR to activate RpoS, thereby initiating carotenoid production. Survival genes such as those responsible for the production of carotenoids of the plant‐pathogenic P. ananatis must be expressed promptly to overcome stressful environments and compete with other microorganisms. This mechanism is likely maintained by a brake with excellent performance, such as EanR.
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Affiliation(s)
- Okhee Choi
- Institute of Agriculture and Life Science, Gyeongsang National University, Jinju, Korea
| | - Byeongsam Kang
- Division of Applied Life Science, Gyeongsang National University, Jinju, Korea
| | - Yongsang Lee
- Division of Applied Life Science, Gyeongsang National University, Jinju, Korea
| | - Yeyeong Lee
- Department of Plant Medicine, Gyeongsang National University, Jinju, Korea
| | - Jinwoo Kim
- Institute of Agriculture and Life Science, Gyeongsang National University, Jinju, Korea.,Division of Applied Life Science, Gyeongsang National University, Jinju, Korea.,Department of Plant Medicine, Gyeongsang National University, Jinju, Korea
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14
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The Small RNA sr8384 Is a Crucial Regulator of Cell Growth in Solventogenic Clostridia. Appl Environ Microbiol 2020; 86:AEM.00665-20. [PMID: 32358006 DOI: 10.1128/aem.00665-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 04/27/2020] [Indexed: 01/08/2023] Open
Abstract
Small RNAs (sRNAs) are crucial regulatory molecules in organisms and are well-known not only for their roles in the control of diverse crucial biological processes but also for their value in regulation rewiring. However, to date, in Gram-positive anaerobic solventogenic clostridia (a group of important industrial bacteria with exceptional substrate and product diversity), sRNAs remain minimally explored, and thus there is a lack of detailed understanding regarding these important molecules and their use as targets for genetic improvement. Here, we performed large-scale phenotypic screens of a transposon-mediated mutant library of Clostridium acetobutylicum, a typical solventogenic clostridial species, and discovered a novel sRNA (sr8384) that functions as a crucial regulator of cell growth. Comparative transcriptomic data combined with genetic and biochemical analyses revealed that sr8384 acts as a pleiotropic regulator and controls multiple targets that are associated with crucial biological processes through direct or indirect interactions. Notably, the in vivo expression level of sr8384 determined the cell growth rate, thereby affecting the solvent titer and productivity. These findings indicate the importance of the sr8384-mediated regulatory network in C. acetobutylicum Furthermore, a homolog of sr8384 was discovered and proven to be functional in another important Clostridium species, C. beijerinckii, suggesting the potential broad role of this sRNA in clostridia. Our work showcases a previously unknown potent and complex role of sRNAs in clostridia, providing new opportunities for understanding and engineering these anaerobes.IMPORTANCE The uses of sRNAs as new resources for functional studies and strain modifications are promising strategies in microorganisms. However, these crucial regulatory molecules have hardly been explored in industrially important solventogenic clostridia. Here, we identified sr8384 as a novel determinant sRNA controlling the cell growth of solventogenic Clostridium acetobutylicum Based on a detailed functional analysis, we further reveal the pleiotropic function of sr8384 and its multiple direct and indirect crucial targets, which represents a valuable source for understanding and optimizing this anaerobe. Of note, manipulation of this sRNA achieves improved cell growth and solvent synthesis. Our findings provide a new perspective for future studies on regulatory sRNAs in clostridia.
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15
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Gao L, Wu X, Zhu C, Jin Z, Wang W, Xia X. Metabolic engineering to improve the biomanufacturing efficiency of acetic acid bacteria: advances and prospects. Crit Rev Biotechnol 2020; 40:522-538. [DOI: 10.1080/07388551.2020.1743231] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Ling Gao
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, PR China
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology Shandong Academy of Sciences, Jinan, PR China
| | - Xiaodan Wu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education School of Biotechnology, Jiangnan University, Wuxi, PR China
| | - Cailin Zhu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education School of Biotechnology, Jiangnan University, Wuxi, PR China
| | - Zhengyu Jin
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, PR China
| | - Wu Wang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education School of Biotechnology, Jiangnan University, Wuxi, PR China
| | - Xiaole Xia
- The Key Laboratory of Industrial Biotechnology, Ministry of Education School of Biotechnology, Jiangnan University, Wuxi, PR China
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16
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Han R, Haning K, Gonzalez-Rivera JC, Yang Y, Li R, Cho SH, Huang J, Simonsen BA, Yang S, Contreras LM. Multiple Small RNAs Interact to Co-regulate Ethanol Tolerance in Zymomonas mobilis. Front Bioeng Biotechnol 2020; 8:155. [PMID: 32195236 PMCID: PMC7064620 DOI: 10.3389/fbioe.2020.00155] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 02/14/2020] [Indexed: 01/18/2023] Open
Abstract
sRNAs represent a powerful class of regulators that influences multiple mRNA targets in response to environmental changes. However, very few direct sRNA-sRNA interactions have been deeply studied in any organism. Zymomonas mobilis is a bacterium with unique ethanol-producing metabolic pathways in which multiple small RNAs (sRNAs) have recently been identified, some of which show differential expression in ethanol stress. In this study, we show that two sRNAs (Zms4 and Zms6) are upregulated under ethanol stress and have significant impacts on ethanol tolerance and production in Z. mobilis. We conducted multi-omics analysis (combining transcriptomics and sRNA-immunoprecipitation) to map gene networks under the influence of their regulation. We confirmed that Zms4 and Zms6 bind multiple RNA targets and regulate their expressions, influencing many downstream pathways important to ethanol tolerance and production. In particular, Zms4 and Zms6 interact with each other as well as many other sRNAs, forming a novel sRNA-sRNA direct interaction network. This study thus uncovers a sRNA network that co-orchestrates multiple ethanol related pathways through a diverse set of mRNA targets and a large number of sRNAs. To our knowledge, this study represents one of the largest sRNA-sRNA direct interactions uncovered so far.
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Affiliation(s)
- Runhua Han
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, United States
| | - Katie Haning
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, United States
| | - Juan C Gonzalez-Rivera
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, United States
| | - Yongfu Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Environmental Microbial Technology Center of Hubei Province, and School of Life Sciences, Hubei University, Wuhan, China
| | - Runxia Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Environmental Microbial Technology Center of Hubei Province, and School of Life Sciences, Hubei University, Wuhan, China
| | - Seung Hee Cho
- Institute for Cellular and Molecular Biology, College of Natural Sciences, The University of Texas at Austin, Austin, TX, United States
| | - Ju Huang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Environmental Microbial Technology Center of Hubei Province, and School of Life Sciences, Hubei University, Wuhan, China
| | - Bobi A Simonsen
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, United States
| | - Shihui Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Environmental Microbial Technology Center of Hubei Province, and School of Life Sciences, Hubei University, Wuhan, China
| | - Lydia M Contreras
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, United States.,Institute for Cellular and Molecular Biology, College of Natural Sciences, The University of Texas at Austin, Austin, TX, United States
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17
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Haning K, Engels SM, Williams P, Arnold M, Contreras LM. Applying a New REFINE Approach in Zymomonas mobilis Identifies Novel sRNAs That Confer Improved Stress Tolerance Phenotypes. Front Microbiol 2020; 10:2987. [PMID: 31998271 PMCID: PMC6970203 DOI: 10.3389/fmicb.2019.02987] [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: 09/23/2019] [Accepted: 12/10/2019] [Indexed: 12/19/2022] Open
Abstract
As global controllers of gene expression, small RNAs represent powerful tools for engineering complex phenotypes. However, a general challenge prevents the more widespread use of sRNA engineering strategies: mechanistic analysis of these regulators in bacteria lags far behind their high-throughput search and discovery. This makes it difficult to understand how to efficiently identify useful sRNAs to engineer a phenotype of interest. To help address this, we developed a forward systems approach to identify naturally occurring sRNAs relevant to a desired phenotype: RNA-seq Examiner for Phenotype-Informed Network Engineering (REFINE). This pipeline uses existing RNA-seq datasets under different growth conditions. It filters the total transcriptome to locate and rank regulatory-RNA-containing regions that can influence a metabolic phenotype of interest, without the need for previous mechanistic characterization. Application of this approach led to the uncovering of six novel sRNAs related to ethanol tolerance in non-model ethanol-producing bacterium Zymomonas mobilis. Furthermore, upon overexpressing multiple sRNA candidates predicted by REFINE, we demonstrate improved ethanol tolerance reflected by up to an approximately twofold increase in relative growth rate compared to controls not expressing these sRNAs in 7% ethanol (v/v) RMG-supplemented media. In this way, the REFINE approach informs strain-engineering strategies that we expect are applicable for general strain engineering.
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Affiliation(s)
- Katie Haning
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, United States
| | - Sean M. Engels
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, United States
| | - Paige Williams
- Department of Aerospace Engineering & Engineering Mechanics, The University of Texas at Austin, Austin, TX, United States
| | - Margaret Arnold
- Department of Computer Science and Engineering, School of Engineering and Applied Sciences, University at Buffalo, Buffalo, NY, United States
| | - Lydia M. Contreras
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, United States
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, United States
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18
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RNA sequencing reveals small RNAs in Bacillus pumilus under different growth phases of the protease fermentation process. Appl Microbiol Biotechnol 2019; 104:833-852. [PMID: 31848654 DOI: 10.1007/s00253-019-10276-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 11/06/2019] [Accepted: 11/23/2019] [Indexed: 10/25/2022]
Abstract
Bacillus pumilus, an endospore-forming soil bacterium, produces a wide array of extracellular proteins, such as proteases, which are already applied in the chemical, detergent and leather industries. Small noncoding regulatory RNAs (sRNAs) in bacteria are important RNA regulators that act in response to various environmental signals. Here, an RNA-seq-based transcriptome analysis was applied to B. pumilus SCU11, a strain that produces extracellular alkaline protease, across various growth phases of the protease fermentation process. Through bioinformatics screening of the sequencing data and visual inspection, 84 putative regulatory sRNAs were identified in B. pumilus, including 21 antisense sRNAs and 63 sRNAs in intergenic regions. We experimentally validated the expression of 48 intergenic sRNAs by quantitative RT-PCR (qRT-PCR). Meanwhile, the expression of 6 novel sRNAs was confirmed by northern blotting, and the expression profiles of 5 sRNAs showed close correlation with the growth phase. We revealed that the sRNA Bpsr137 was involved in flagellum and biofilm formation in B. pumilus. The identification of a global set of sRNAs increases the inventory of regulatory sRNAs in Bacillus and implies the important regulatory roles of sRNA in B. pumilus. These findings will contribute another dimension to the optimization of crucial metabolic activities of B. pumilus during a productive fermentation process.
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19
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Reprogramming bacteria with RNA regulators. Biochem Soc Trans 2019; 47:1279-1289. [DOI: 10.1042/bst20190173] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 09/13/2019] [Accepted: 09/16/2019] [Indexed: 12/20/2022]
Abstract
Abstract
The revolution of genomics and growth of systems biology urged the creation of synthetic biology, an engineering discipline aiming at recreating and reprogramming cellular functions for industrial needs. There has been a huge effort in synthetic biology to develop versatile and programmable genetic regulators that would enable the precise control of gene expression. Synthetic RNA components have emerged as a solution, offering a diverse range of programmable functions, including signal sensing, gene regulation and the modulation of molecular interactions. Owing to their compactness, structure and way of action, several types of RNA devices that act on DNA, RNA and protein have been characterized and applied in synthetic biology. RNA-based approaches are more ‘economical' for the cell, since they are generally not translated. These RNA-based strategies act on a much shorter time scale than transcription-based ones and can be more efficient than protein-based mechanisms. In this review, we explore these RNA components as building blocks in the RNA synthetic biology field, first by explaining their natural mode of action and secondly discussing how these RNA components have been exploited to rewire bacterial regulatory circuitry.
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20
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Zhu Z, Yang P, Wu Z, Zhang J, Du G. Systemic understanding of Lactococcus lactis response to acid stress using transcriptomics approaches. J Ind Microbiol Biotechnol 2019; 46:1621-1629. [PMID: 31414323 DOI: 10.1007/s10295-019-02226-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Accepted: 08/07/2019] [Indexed: 11/25/2022]
Abstract
During fermentation, acid stress caused by the accumulation of acidic metabolites seriously affects the metabolic activity and production capacity of microbial cells. To elucidate the acid stress-tolerance mechanisms of microbial cells, we performed genome mutagenesis combined with high-throughput technologies to screen acid stress-tolerant strains. Mutant strain Lactococcus lactis WH101 showed a 16,000-fold higher survival rate than that of the parent strain after 5 h of acid shock at pH 4.0 and maintained higher ATP, NH4+, and intracellular pH (pHi) levels during acid stress. Additionally, comparative transcriptomics analysis revealed enhanced regulation of carbohydrate metabolism and sugar transport to provide additional energy, amino acid metabolism and transport to maintain pHi homeostasis and ATP generation, and fatty acid metabolism to enhance cellular acid tolerance. Moreover, overexpression of identified components resulted in 12.6- and 12.9-fold higher survival rates after acid shock for 3 h at pH 4.0 in L. lactis (ArcB) and L. lactis (MalQ) compared to the control strain, respectively. These findings provide valuable insight into the acid stress-response mechanisms of L. lactis and promote the further development of robust industrial strains.
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Affiliation(s)
- Zhengming Zhu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Peishan Yang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Zhimeng Wu
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Juan Zhang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China. .,School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.
| | - Guocheng Du
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
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21
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Zhu Z, Yang J, Yang P, Wu Z, Zhang J, Du G. Enhanced acid-stress tolerance in Lactococcus lactis NZ9000 by overexpression of ABC transporters. Microb Cell Fact 2019; 18:136. [PMID: 31409416 PMCID: PMC6693162 DOI: 10.1186/s12934-019-1188-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 08/07/2019] [Indexed: 12/19/2022] Open
Abstract
Background Microbial cell factories are widely used in the production of acidic products such as organic acids and amino acids. However, the metabolic activity of microbial cells and their production efficiency are severely inhibited with the accumulation of intracellular acidic metabolites. Therefore, it remains a key issue to enhance the acid tolerance of microbial cells. In this study, we investigated the effects of four ATP-binding cassette (ABC) transporters on acid stress tolerance in Lactococcus lactis. Results Overexpressing the rbsA, rbsB, msmK, and dppA genes exhibited 5.8-, 12.2-, 213.7-, and 5.2-fold higher survival rates than the control strain, respectively, after acid shock for 3 h at pH 4.0. Subsequently, transcriptional profile alterations in recombinant strains were analyzed during acid stress. The differentially expressed genes associated with cold-shock proteins (csp), fatty acid biosynthesis (fabH), and coenzyme A biosynthesis (coaD) were up-regulated in the four recombinant strains during acid stress. Additionally, some genes were differentially expressed in specific recombinant strains. For example, in L. lactis (RbsB), genes involved in the pyrimidine biosynthetic pathway (pyrCBDEK) and glycine or betaine transport process (busAA and busAB) were up-regulated during acid stress, and the argG genes showed up-regulations in L. lactis (MsmK). Finally, we found that overexpression of the ABC transporters RbsB and MsmK increased intracellular ATP concentrations to protect cells against acidic damage in the initial stage of acid stress. Furthermore, L. lactis (MsmK) consistently maintained elevated ATP concentrations under acid stress. Conclusions This study elucidates the common and specific mechanisms underlying improved acid tolerance by manipulating ABC transporters and provides a further understanding of the role of ABC transporters in acid-stress tolerance. Electronic supplementary material The online version of this article (10.1186/s12934-019-1188-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zhengming Zhu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Jinhua Yang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Peishan Yang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Zhimeng Wu
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Juan Zhang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China. .,School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.
| | - Guocheng Du
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
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22
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Expanded synthetic small regulatory RNA expression platforms for rapid and multiplex gene expression knockdown. Metab Eng 2019; 54:180-190. [DOI: 10.1016/j.ymben.2019.04.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 04/11/2019] [Accepted: 04/13/2019] [Indexed: 12/28/2022]
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23
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On a stake-out: Mycobacterial small RNA identification and regulation. Noncoding RNA Res 2019; 4:86-95. [PMID: 32083232 PMCID: PMC7017587 DOI: 10.1016/j.ncrna.2019.05.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 04/30/2019] [Accepted: 05/12/2019] [Indexed: 12/23/2022] Open
Abstract
Persistence of mycobacteria in the hostile environment of human macrophage is pivotal for its successful pathogenesis. Rapid adaptation to diverse stresses is the key aspect for their survival in the host cells. A range of heterogeneous mechanisms operate in bacteria to retaliate stress conditions. Small RNAs (sRNA) have been implicated in many of those mechanisms in either a single or multiple regulatory networks to post-transcriptionally modulate bacterial gene expression. Although small RNA profiling in mycobacteria by advanced technologies like deep sequencing, tilling microarray etc. have identified hundreds of sRNA, however, a handful of those small RNAs have been unearthed with precise regulatory mechanism. Extensive investigations on sRNA-mediated gene regulations in eubacteria like Escherichia coli revealed the existence of a plethora of distinctive sRNA mechanisms e.g. base pairing, protein sequestration, RNA decoy etc. Increasing studies on mycobacterial sRNA also discovered several eccentric mechanisms where sRNAs act at the posttranscriptional stage to either activate or repress target gene expression that lead to promote mycobacterial survival in stresses. Several intrinsic features like high GC content, absence of any homologue of abundant RNA chaperones, Hfq and ProQ, isolate sRNA mechanisms of mycobacteria from that of other bacteria. An insightful approach has been taken in this review to describe sRNA identification and its regulations in mycobacterial species especially in Mycobacterium tuberculosis.
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Key Words
- Anti-antisense
- Antisense
- Base pairing
- CDS, coding sequence
- Gene regulation by sRNA
- IGR, intergenic region
- ORF, open reading frame
- RBS, Ribosome binding site
- RNAP, RNA polymerase
- SD, Shine Dalgarno sequence
- Small RNAs
- TF, transcription factor
- TIR, translation initiation region
- UTR, untranslated region
- nt, nucleotide
- sRNA, small RNA
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Zhang K, Lu X, Li Y, Jiang X, Liu L, Wang H. New technologies provide more metabolic engineering strategies for bioethanol production in Zymomonas mobilis. Appl Microbiol Biotechnol 2019; 103:2087-2099. [PMID: 30661108 DOI: 10.1007/s00253-019-09620-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 01/02/2019] [Accepted: 01/03/2019] [Indexed: 02/06/2023]
Abstract
Bioethanol has been considered as a potentially renewable energy source, and metabolic engineering plays an important role in the production of biofuels. As an efficient ethanol-producing bacterium, Zymomonas mobilis has garnered special attention due to its high sugar uptake, ethanol yield, and tolerance. Different metabolic engineering strategies have been used to establish new metabolic pathways for Z. mobilis to broaden its substrate range, remove competing pathways, and enhance its tolerance to ethanol and lignocellulosic hydrolysate inhibitors. Recent advances in omics technology, computational modeling and simulation, system biology, and synthetic biology contribute to the efficient re-design and manipulation of microbes via metabolic engineering at the whole-cell level. In this review, we summarize the progress of some new technologies used for metabolic engineering to improve bioethanol production and tolerance in Z. mobilis. Some successful examples of metabolic engineering used to develop strains for ethanol production are described in detail. Lastly, some important strategies for future metabolic engineering efforts are also highlighted.
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Affiliation(s)
- Kun Zhang
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, 453007, Henan, China
| | - Xinxin Lu
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, 453007, Henan, China
| | - Yi Li
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, 453007, Henan, China
| | - Xiaobing Jiang
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, 453007, Henan, China
| | - Lei Liu
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, 453007, Henan, China
| | - Hailei Wang
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, 453007, Henan, China.
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25
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Abstract
In bacteria and archaea, small RNAs (sRNAs) regulate complex networks through antisense interactions with target mRNAs in trans, and riboswitches regulate gene expression in cis based on the ability to bind small-molecule ligands. Although our understanding and characterization of these two important regulatory RNA classes is far from complete, these RNA-based mechanisms have proven useful for a wide variety of synthetic biology applications. Besides classic and contemporary applications in the realm of metabolic engineering and orthogonal gene control, this review also covers newer applications of regulatory RNAs as biosensors, logic gates, and tools to determine RNA-RNA interactions. A separate section focuses on critical insights gained and challenges posed by fundamental studies of sRNAs and riboswitches that should aid future development of synthetic regulatory RNAs.
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26
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Leistra AN, Curtis NC, Contreras LM. Regulatory non-coding sRNAs in bacterial metabolic pathway engineering. Metab Eng 2018; 52:190-214. [PMID: 30513348 DOI: 10.1016/j.ymben.2018.11.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 10/31/2018] [Accepted: 11/29/2018] [Indexed: 12/11/2022]
Abstract
Non-coding RNAs (ncRNAs) are versatile and powerful controllers of gene expression that have been increasingly linked to cellular metabolism and phenotype. In bacteria, identified and characterized ncRNAs range from trans-acting, multi-target small non-coding RNAs to dynamic, cis-encoded regulatory untranslated regions and riboswitches. These native regulators have inspired the design and construction of many synthetic RNA devices. In this work, we review the design, characterization, and impact of ncRNAs in engineering both native and exogenous metabolic pathways in bacteria. We also consider the opportunities afforded by recent high-throughput approaches for characterizing sRNA regulators and their corresponding networks to showcase their potential applications and impact in engineering bacterial metabolism.
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Affiliation(s)
- Abigail N Leistra
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E. Dean Keeton Street Stop C0400, Austin, TX 78712, USA
| | - Nicholas C Curtis
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E. Dean Keeton Street Stop C0400, Austin, TX 78712, USA
| | - Lydia M Contreras
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E. Dean Keeton Street Stop C0400, Austin, TX 78712, USA.
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27
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Charubin K, Bennett RK, Fast AG, Papoutsakis ET. Engineering Clostridium organisms as microbial cell-factories: challenges & opportunities. Metab Eng 2018; 50:173-191. [DOI: 10.1016/j.ymben.2018.07.012] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/18/2018] [Accepted: 07/19/2018] [Indexed: 11/25/2022]
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28
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Escherichia coli as a host for metabolic engineering. Metab Eng 2018; 50:16-46. [DOI: 10.1016/j.ymben.2018.04.008] [Citation(s) in RCA: 181] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 04/11/2018] [Accepted: 04/12/2018] [Indexed: 12/21/2022]
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29
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Abstract
As the transcriptional and post-transcriptional regulators of gene expression, small RNAs (sRNAs) play important roles in every domain of life in organisms. It has been discovered gradually that bacteria possess multiple means of gene regulation using RNAs. They have been continuously used as model organisms for photosynthesis, metabolism, biotechnology, evolution, and nitrogen fixation for many decades. Cyanobacteria, one of the most ancient life forms, constitute all kinds of photoautotrophic bacteria and exist in almost any environment on this planet. It is believed that a complex RNA-based regulatory mechanism functions in cyanobacteria to help them adapt to changes and stresses in diverse environments. Although lagging far behind other model microorganisms, such as yeast and Escherichia coli, more and more non-coding regulatory sRNAs have been recognized in cyanobacteria during the past decades. In this article, by focusing on cyanobacterial sRNAs, the approaches for detection and targeting of sRNAs will be summarized, four major mechanisms and regulatory functions will be generalized, eight types of cis-encoded sRNA and four types of trans-encoded sRNAs will be reviewed in detail, and their possible physiological functions will be further discussed.
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Affiliation(s)
- Jinlu Hu
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Qiang Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan, China.,University of the Chinese Academy of Sciences, Beijing, China
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30
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Zhu Z, Ji X, Wu Z, Zhang J, Du G. Improved acid-stress tolerance of Lactococcus lactis NZ9000 and Escherichia coli BL21 by overexpression of the anti-acid component recT. J Ind Microbiol Biotechnol 2018; 45:1091-1101. [PMID: 30232653 DOI: 10.1007/s10295-018-2075-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 08/22/2018] [Indexed: 12/01/2022]
Abstract
Acid accumulation caused by carbon metabolism severely affects the fermentation performance of microbial cells. Here, different sources of the recT gene involved in homologous recombination were functionally overexpressed in Lactococcus lactis NZ9000 and Escherichia coli BL21, and their acid-stress tolerances were investigated. Our results showed that L. lactis NZ9000 (ERecT and LRecT) strains showed 1.4- and 10.4-fold higher survival rates against lactic acid (pH 4.0), respectively, and that E. coli BL21 (ERecT) showed 16.7- and 9.4-fold higher survival rates than the control strain against lactic acid (pH 3.8) for 40 and 60 min, respectively. Additionally, we found that recT overexpression in L. lactis NZ9000 improved their growth under acid-stress conditions, as well as increased salt- and ethanol-stress tolerance and intracellular ATP concentrations in L. lactis NZ9000. These findings demonstrated the efficacy of recT overexpression for enhancing acid-stress tolerance and provided a promising strategy for insertion of anti-acid components in different hosts.
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Affiliation(s)
- Zhengming Zhu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Xiaomei Ji
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Zhimeng Wu
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China. .,School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.
| | - Juan Zhang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China. .,School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.
| | - Guocheng Du
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
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Small and Low but Potent: the Complex Regulatory Role of the Small RNA SolB in Solventogenesis in Clostridium acetobutylicum. Appl Environ Microbiol 2018; 84:AEM.00597-18. [PMID: 29728392 DOI: 10.1128/aem.00597-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 05/01/2018] [Indexed: 12/15/2022] Open
Abstract
The recently revived Clostridium acetobutylicum-based acetone-butanol-ethanol (ABE) fermentation is widely celebrated and studied for its impact on industrial biotechnology. C. acetobutylicum has been studied and engineered extensively, yet critical areas of the molecular basis for how solvent formation is regulated remain unresolved. The core solventogenic genes (adhE1/aad, ctfA, ctfB, and adc) are carried on the sol locus of the pSOL1 megaplasmid, whose loss leads to asporogenous, "degenerate" cells. The sol locus includes a noncoding small RNA (sRNA), SolB, whose role is presumed to be critical for solventogenesis but has eluded resolution. In the present study, SolB overexpression downregulated the sol-locus genes at the transcript level, resulting in attenuated protein expression and a solvent-deficient phenotype, thus suggesting that SolB affects expression of all sol-locus transcripts and seemingly validating its hypothesized role as a repressor. However, deletion of solB resulted in a total loss of acetone production and severe attenuation of butanol formation, with complex effects on sol-locus genes and proteins: it had a small impact on adc mRNA or its corresponding protein (acetoacetate decarboxylase) expression level, somewhat reduced adhE1 and ctfA-ctfB mRNA levels, and abolished the ctfA-ctfB-encoded coenzyme A transferase (CoAT) activity. Computational predictions support a model whereby SolB expressed at low levels enables the stabilization and translation of sol-locus transcripts to facilitate tuning of the production of various solvents depending on the prevailing culture conditions. A key predicted SolB target is the ribosome binding site (RBS) of the ctfA transcript, and this was verified by expressing variants of the ctfA-ctfB genes to demonstrate the importance of SolB for acetone formation.IMPORTANCE Small noncoding RNAs regulate many important metabolic and developmental programs in prokaryotes, but their role in anaerobes has been explored minimally. Regulation of solvent formation in the important industrial organism C. acetobutylicum remains incompletely understood. While the genes for solvent formation and their promoters are known, the means by which this organism tunes the ratios of key solvents, notably the butanol/acetone ratio to balance its electron resources, remains unknown. Significantly, the roles of several coding and noncoding genes in the sol locus in tuning the solvent formation ratios have not been explored. Here we show that the small RNA SolB fine-tunes the expression of solvents, with acetone formation being a key target, by regulating the translation of the acetone formation rate-limiting enzyme, the coenzyme A transferase (CoAT). It is notable that SolB expressed at very low levels enables CoAT translation, while at high, nonphysiological expression levels, it leads to degradation of the corresponding transcript.
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Sun T, Li S, Song X, Diao J, Chen L, Zhang W. Toolboxes for cyanobacteria: Recent advances and future direction. Biotechnol Adv 2018; 36:1293-1307. [DOI: 10.1016/j.biotechadv.2018.04.007] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 04/09/2018] [Accepted: 04/26/2018] [Indexed: 12/20/2022]
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Run S, Tian P. Improved Tolerance of Escherichia coli to Propionic Acid by Overexpression of Sigma Factor RpoS. APPL BIOCHEM MICRO+ 2018. [DOI: 10.1134/s0003683818030122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Biological and regulatory roles of acid-induced small RNA RyeC in Salmonella Typhimurium. Biochimie 2018; 150:48-56. [PMID: 29730297 DOI: 10.1016/j.biochi.2018.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 05/01/2018] [Indexed: 12/23/2022]
Abstract
Salmonella Typhimurium is an enteric pathogen that has evolved masterful strategies to enable survival under stress conditions both within and outside a host. The acid tolerance response (ATR) is one such mechanism that enhances the viability of acid adapted bacteria to lethal pH levels. While numerous studies exist on the protein coding components of this response, there is very little data on the roles of small RNAs (sRNAs). These non-coding RNA molecules have recently been shown to play roles as regulators of bacterial stress response and virulence pathways. They function through complementary base pairing interactions with target mRNAs and affect their translation and/or stability. There are also a few that directly bind to proteins by mimicking their respective targets. Here, we identify several sRNAs expressed during the ATR of S. Typhimurium and characterize one highly induced candidate, RyeC. Further, we identify ptsI as a trans-encoded target that is directly regulated by this sRNA. From a functional perspective, over-expression of RyeC in Salmonella produced a general attenuation of several in vitro phenotypes including acid survival, motility, adhesion and invasion of epithelial cell lines as well as replication within macrophages. Together, this study highlights the diverse roles played by sRNAs in acid tolerance and virulence of S. Typhimurium.
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Bi Y, Pei G, Sun T, Chen Z, Chen L, Zhang W. Regulation Mechanism Mediated by Trans-Encoded sRNA Nc117 in Short Chain Alcohols Tolerance in Synechocystis sp. PCC 6803. Front Microbiol 2018; 9:863. [PMID: 29780373 PMCID: PMC5946031 DOI: 10.3389/fmicb.2018.00863] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 04/13/2018] [Indexed: 11/13/2022] Open
Abstract
Microbial small RNAs (sRNAs) play essential roles against many stress conditions in cyanobacteria. However, little is known on their regulatory mechanisms on biofuels tolerance. In our previous sRNA analysis, a trans-encoded sRNA Nc117 was found involved in the tolerance to ethanol and 1-butanol in Synechocystis sp. PCC 6803. However, its functional mechanism is yet to be determined. In this study, functional characterization of sRNA Nc117 was performed. Briefly, the exact length of the trans-encoded sRNA Nc117 was determined to be 102 nucleotides using 3′ RACE, and the positive regulation of Nc117 on short chain alcohols tolerance was further confirmed. Then, computational target prediction and transcriptomic analysis were integrated to explore the potential targets of Nc117. A total of 119 up-regulated and 116 down-regulated genes were identified in nc117 overexpression strain compared with the wild type by comparative transcriptomic analysis, among which the upstream regions of five genes were overlapped with those predicted by computational target approach. Based on the phenotype analysis of gene deletion and overexpression strains under short chain alcohols stress, one gene slr0007 encoding D-glycero-alpha-D-manno-heptose 1-phosphate guanylyltransferase was determined as a potential target of Nc117, suggesting that the synthesis of LPS or S-layer glycoprotein may be responsible for the tolerance enhancement. As the first reported trans-encoded sRNA positively regulating biofuels tolerance in cyanobacteria, this study not only provided evidence for a new regulatory mechanism of trans-encoded sRNA in cyanobacteria, but also valuable information for rational construction of high-tolerant cyanobacterial chassis.
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Affiliation(s)
- Yanqi Bi
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering, Ministry of Education of the People's Republic of China, Tianjin, China.,Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Guangsheng Pei
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering, Ministry of Education of the People's Republic of China, Tianjin, China.,Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Tao Sun
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering, Ministry of Education of the People's Republic of China, Tianjin, China.,Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Zixi Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering, Ministry of Education of the People's Republic of China, Tianjin, China.,Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering, Ministry of Education of the People's Republic of China, Tianjin, China.,Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering, Ministry of Education of the People's Republic of China, Tianjin, China.,Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China.,Center for Biosafety Research and Strategy, Tianjin University, Tianjin, China
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Wang X, He Q, Yang Y, Wang J, Haning K, Hu Y, Wu B, He M, Zhang Y, Bao J, Contreras LM, Yang S. Advances and prospects in metabolic engineering of Zymomonas mobilis. Metab Eng 2018; 50:57-73. [PMID: 29627506 DOI: 10.1016/j.ymben.2018.04.001] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 03/31/2018] [Accepted: 04/01/2018] [Indexed: 12/22/2022]
Abstract
Biorefinery of biomass-based biofuels and biochemicals by microorganisms is a competitive alternative of traditional petroleum refineries. Zymomonas mobilis is a natural ethanologen with many desirable characteristics, which makes it an ideal industrial microbial biocatalyst for commercial production of desirable bioproducts through metabolic engineering. In this review, we summarize the metabolic engineering progress achieved in Z. mobilis to expand its substrate and product ranges as well as to enhance its robustness against stressful conditions such as inhibitory compounds within the lignocellulosic hydrolysates and slurries. We also discuss a few metabolic engineering strategies that can be applied in Z. mobilis to further develop it as a robust workhorse for economic lignocellulosic bioproducts. In addition, we briefly review the progress of metabolic engineering in Z. mobilis related to the classical synthetic biology cycle of "Design-Build-Test-Learn", as well as the progress and potential to develop Z. mobilis as a model chassis for biorefinery practices in the synthetic biology era.
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Affiliation(s)
- Xia Wang
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Environmental Microbial Technology Center of Hubei Province, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan 430062, China.
| | - Qiaoning He
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Environmental Microbial Technology Center of Hubei Province, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan 430062, China.
| | - Yongfu Yang
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Environmental Microbial Technology Center of Hubei Province, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan 430062, China.
| | - Jingwen Wang
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Environmental Microbial Technology Center of Hubei Province, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan 430062, China.
| | - Katie Haning
- Institute for Cellular and Molecular Biology, Department of Chemical Engineering, Cockrell School of Engineering, University of Texas at Austin, Austin, TX, United States.
| | - Yun Hu
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Environmental Microbial Technology Center of Hubei Province, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan 430062, China.
| | - Bo Wu
- Key Laboratory of Development and Application of Rural Renewable Energy, Biomass Energy Technology Research Centre, Biogas Institute of Ministry of Agriculture, South Renmin Road, Chengdu 610041, China.
| | - Mingxiong He
- Key Laboratory of Development and Application of Rural Renewable Energy, Biomass Energy Technology Research Centre, Biogas Institute of Ministry of Agriculture, South Renmin Road, Chengdu 610041, China.
| | - Yaoping Zhang
- DOE-Great Lakes Bioenergy Research Center (GLBRC), University of Wisconsin-Madison, Madison, WI, United States.
| | - Jie Bao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
| | - Lydia M Contreras
- Institute for Cellular and Molecular Biology, Department of Chemical Engineering, Cockrell School of Engineering, University of Texas at Austin, Austin, TX, United States.
| | - Shihui Yang
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Environmental Microbial Technology Center of Hubei Province, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan 430062, China.
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Functional Expression of the Clostridium ljungdahlii Acetyl-Coenzyme A Synthase in Clostridium acetobutylicum as Demonstrated by a Novel In Vivo CO Exchange Activity En Route to Heterologous Installation of a Functional Wood-Ljungdahl Pathway. Appl Environ Microbiol 2018; 84:AEM.02307-17. [PMID: 29374033 DOI: 10.1128/aem.02307-17] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 01/21/2018] [Indexed: 11/20/2022] Open
Abstract
Engineering the Wood-Ljungdahl pathway (WLP) in the established industrial organism Clostridium acetobutylicum would allow for the conversion of carbohydrates into butanol, acetone, and other metabolites at higher yields than are currently possible, while minimizing CO2 and H2 release. To this effect, we expressed 11 Clostridium ljungdahlii core genes coding for enzymes and accessory proteins of the WLP in Clostridium acetobutylicum The engineered WLP in C. acetobutylicum showed functionality of the eastern branch of the pathway based on the formation of labeled 5,10-methylenetetrahydrofolate from 13C-labeled formate, as well as functionality of the western branch as evidenced by the formation of CO from CO2 However, the lack of labeling in acetate and butyrate pools indicated that the connection between the two branches is not functional. The focus of our investigation then centered on the functional expression of the acetyl-coenzyme A (CoA) synthase (ACS), which forms a complex with the CO dehydrogenase (CODH) and serves to link the two branches of the WLP. The CODH/ACS complex catalyzes the reduction of CO2 to CO and the condensation of CO with a methyl group to form acetyl-CoA, respectively. Here, we show the simultaneous activities of the two recombinant enzymes. We demonstrate in vivo the classical in vitro ACS carbonyl carbon exchange assay, whereby the carbonyl carbon of acetyl-CoA is exchanged with the CO carbon. Our data suggest that the low heterologous expression of ACS may limit the functionality of the heterologous WLP in C. acetobutylicum IMPORTANCE The bifunctional carbon monoxide dehydrogenase/acetyl-CoA synthase (CODH/ACS) from C. ljungdahlii was heterologously expressed in the obligate heterotroph C. acetobutylicum The functional activity of the CODH was confirmed through both the oxidation and reduction of CO, as had previously been shown for the heterologous CODH from Clostridium carboxidivorans Significantly, a novel in vivo assay for ACS exchange activity using 13C-tracers was developed and used to confirm functional ACS expression.
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38
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Small RNA-mediated regulation in bacteria: A growing palette of diverse mechanisms. Gene 2018; 656:60-72. [PMID: 29501814 DOI: 10.1016/j.gene.2018.02.068] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 02/19/2018] [Accepted: 02/27/2018] [Indexed: 11/23/2022]
Abstract
Small RNAs (sRNAs) in bacteria have evolved with diverse mechanisms to balance their target gene expression in response to changes in the environment. Accumulating studies on bacterial regulatory processes firmly established that sRNAs modulate their target gene expression generally at the posttranscriptional level. Identification of large number of sRNAs by advanced technologies, like deep sequencing, tilling microarray, indicates the existence of a plethora of distinctive sRNA-mediated regulatory mechanisms in bacteria. Types of the novel mechanisms are increasing with the discovery of new sRNAs. Complementary base pairing between sRNAs and target RNAs assisted by RNA chaperones like Hfq and ProQ, in many occasions, to regulate the cognate gene expression is prevalent in sRNA mechanisms. sRNAs, in most studied cases, can directly base pair with target mRNA to remodel its expression. Base pairing can happen either in the untranslated regions or in the coding regions of mRNA to activate/repress its translation. sRNAs also act as target mimic to titrate away different regulatory RNAs from its target. Other mechanism includes the sequestration of regulatory proteins, especially transcription factors, by sRNAs. Numerous sRNAs, following analogous mechanism, are widespread in bacteria, and thus, has drawn immense attention for the development of RNA-based technologies. Nevertheless, typical sRNA mechanisms are also discovered to be confined in some bacteria. Analysis of the sRNA mechanisms unravels their existence in both the single step processes and the complex regulatory networks with a global effect on cell physiology. This review deals with the diverse array of mechanisms, which sRNAs follow to maintain bacterial lifestyle.
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Biofuel production with a stress-resistant and growth phase-independent promoter: mechanism revealed by in vitro transcription assays. Appl Microbiol Biotechnol 2018; 102:2929-2940. [DOI: 10.1007/s00253-018-8809-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 01/15/2018] [Accepted: 01/22/2018] [Indexed: 12/13/2022]
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40
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Sun T, Li S, Song X, Pei G, Diao J, Cui J, Shi M, Chen L, Zhang W. Re-direction of carbon flux to key precursor malonyl-CoA via artificial small RNAs in photosynthetic Synechocystis sp. PCC 6803. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:26. [PMID: 29441124 PMCID: PMC5798194 DOI: 10.1186/s13068-018-1032-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 01/23/2018] [Indexed: 05/24/2023]
Abstract
BACKGROUND Photosynthetic cyanobacteria have attracted a significant attention as promising chassis to produce renewable fuels and chemicals due to their capability to utilizing solar energy and CO2. Notably, the enhancing supply of key precursors like malonyl-CoA would benefit the production of many bio-compounds. Nevertheless, the lacking of genetic tools in cyanobacteria, especially the knockdown strategies for essential pathways, has seriously restricted the attempts to re-direct carbon flux from the central carbohydrate metabolism to the synthesis of bioproducts. RESULTS Aiming at developing new genetic tools, two small RNA regulatory tools are reported for the model cyanobacterium Synechocystis sp. PCC6803, based on paired termini RNAs as well as the exogenous Hfq chaperone and MicC scaffold (Hfq-MicC) previously developed in Escherichia coli. Both regulatory tools functioned well in regulating exogenous reporter gene lacZ and endogenous glgC gene in Synechocystis sp. PCC6803, achieving a downregulation of gene expression up to 90% compared with wildtype. In addition, the Hfq-MicC tool was developed to simultaneously regulate multiple genes related to essential fatty acids biosynthesis, which led to decreased fatty acids content by 11%. Furthermore, aiming to re-direct the carbon flux, the Hfq-MicC tool was utilized to interfere the competing pathway of malonyl-CoA, achieving an increased intracellular malonyl-CoA abundance up to 41% (~ 698.3 pg/mL/OD730 nm) compared to the wildtype. Finally, the Hfq-MicC system was further modified into an inducible system based on the theophylline-inducible riboswitch. CONCLUSIONS In this study, two small RNA regulatory tools for manipulating essential metabolic pathways and re-directing carbon flux are reported for Synechocystis sp. PCC6803. The work introduces efficient and valuable metabolic regulatory strategies for photosynthetic cyanobacteria.
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Affiliation(s)
- Tao Sun
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072 People’s Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072 People’s Republic of China
| | - Shubin Li
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072 People’s Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072 People’s Republic of China
| | - Xinyu Song
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Guangsheng Pei
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072 People’s Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072 People’s Republic of China
| | - Jinjin Diao
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072 People’s Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072 People’s Republic of China
| | - Jinyu Cui
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072 People’s Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072 People’s Republic of China
| | - Mengliang Shi
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072 People’s Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072 People’s Republic of China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072 People’s Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072 People’s Republic of China
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072 People’s Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072 People’s Republic of China
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, People’s Republic of China
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Jaishankar J, Srivastava P. Molecular Basis of Stationary Phase Survival and Applications. Front Microbiol 2017; 8:2000. [PMID: 29085349 PMCID: PMC5650638 DOI: 10.3389/fmicb.2017.02000] [Citation(s) in RCA: 135] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 09/28/2017] [Indexed: 12/04/2022] Open
Abstract
Stationary phase is the stage when growth ceases but cells remain metabolically active. Several physical and molecular changes take place during this stage that makes them interesting to explore. The characteristic proteins synthesized in the stationary phase are indispensable as they confer viability to the bacteria. Detailed knowledge of these proteins and the genes synthesizing them is required to understand the survival in such nutrient deprived conditions. The promoters, which drive the expression of these genes, are called stationary phase promoters. These promoters exhibit increased activity in the stationary phase and less or no activity in the exponential phase. The vectors constructed based on these promoters are ideal for large-scale protein production due to the absence of any external inducers. A number of recombinant protein production systems have been developed using these promoters. This review describes the stationary phase survival of bacteria, the promoters involved, their importance, regulation, and applications.
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Affiliation(s)
- Jananee Jaishankar
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, New Delhi, India
| | - Preeti Srivastava
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, New Delhi, India
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42
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Gong Z, Nielsen J, Zhou YJ. Engineering Robustness of Microbial Cell Factories. Biotechnol J 2017; 12. [DOI: 10.1002/biot.201700014] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 08/13/2017] [Indexed: 12/25/2022]
Affiliation(s)
- Zhiwei Gong
- Division of BiotechnologyDalian Institute of Chemical PhysicsCAS457 Zhongshan RoadDalian 116023P.R. China
- College of Chemistry and Chemical EngineeringWuhan University of Science and Technology947 Heping RoadWuhan 430081P.R. China
| | - Jens Nielsen
- Department of Biology and Biological EngineeringChalmers University of TechnologyKemivägen 10 Gothenburg SE‐41296Sweden
| | - Yongjin J. Zhou
- Division of BiotechnologyDalian Institute of Chemical PhysicsCAS457 Zhongshan RoadDalian 116023P.R. China
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Ren J, Sang Y, Qin R, Cui Z, Yao YF. 6S RNA is involved in acid resistance and invasion of epithelial cells in Salmonella enterica serovar Typhimurium. Future Microbiol 2017; 12:1045-1057. [PMID: 28796533 DOI: 10.2217/fmb-2017-0055] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
AIM Acid is an important environmental condition encountered frequently by Salmonella enterica serovar Typhimurium during its pathogenesis, but the role of small-noncoding RNAs (sRNAs) in response to acid stress is poorly understood. METHODS We used RNA sequencing to explore acid-responsive sRNAs in S. Typhimurium. RESULTS It identified that 6S RNA encoded by the ssrS was significantly upregulated at pH 3.0. The 6S RNA knockout strain showed a reduced ability to survive at pH 3.0. Additionally, genes in Salmonella pathogenicity island-1 were downregulated in the 6S RNA knockout strain. The loss of 6S RNA significantly reduced S. Typhimurium invasion ability in HeLa cells and virulence in a mouse model. CONCLUSION These findings demonstrate that 6S RNA plays an important role in S. Typhimurium survival under extremely acid conditions and for invasion of epithelial cells.
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Affiliation(s)
- Jie Ren
- Department of Microbiology & Immunology, Laboratory of Bacterial Pathogenesis, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yu Sang
- Department of Microbiology & Immunology, Laboratory of Bacterial Pathogenesis, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Ran Qin
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhongli Cui
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yu-Feng Yao
- Department of Microbiology & Immunology, Laboratory of Bacterial Pathogenesis, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.,Department of Laboratory Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
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44
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Engineering Escherichia coli BL21 genome to improve the heptanoic acid tolerance by using CRISPR-Cas9 system. BIOTECHNOL BIOPROC E 2017. [DOI: 10.1007/s12257-017-0158-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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45
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Ryan D, Mukherjee M, Suar M. The expanding targetome of small RNAs in Salmonella Typhimurium. Biochimie 2017; 137:69-77. [DOI: 10.1016/j.biochi.2017.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Accepted: 03/10/2017] [Indexed: 10/20/2022]
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46
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Pei G, Sun T, Chen S, Chen L, Zhang W. Systematic and functional identification of small non-coding RNAs associated with exogenous biofuel stress in cyanobacterium Synechocystis sp. PCC 6803. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:57. [PMID: 28286552 PMCID: PMC5341163 DOI: 10.1186/s13068-017-0743-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 02/28/2017] [Indexed: 06/06/2023]
Abstract
BACKGROUND The unicellular model cyanobacterium Synechocystis sp. PCC 6803 is considered a promising microbial chassis for biofuel production. However, its low tolerance to biofuel toxicity limits its potential application. Although recent studies showed that bacterial small RNAs (sRNAs) play important roles in regulating cellular processes in response to various stresses, the role of sRNAs in resisting exogenous biofuels is yet to be determined. RESULTS Based on genome-wide sRNA sequencing combined with systematic analysis of previous transcriptomic and proteomic data under the same biofuel or environmental perturbations, we report the identification of 133 trans-encoded sRNA transcripts with high-resolution mapping of sRNAs in Synechocystis, including 23 novel sRNAs identified for the first time. In addition, according to quantitative expression analysis and sRNA regulatory network prediction, sRNAs potentially involved in biofuel tolerance were identified and functionally confirmed by constructing sRNA overexpression or suppression strains of Synechocystis. Notably, overexpression of sRNA Nc117 revealed an improved tolerance to ethanol and butanol, while suppression of Nc117 led to increased sensitivity. CONCLUSIONS The study provided the first comprehensive responses to exogenous biofuels at the sRNA level in Synechocystis and opens an avenue to engineering sRNA regulatory elements for improved biofuel tolerance in the cyanobacterium Synechocystis.
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Affiliation(s)
- Guangsheng Pei
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, 300072 People’s Republic of China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, People’s Republic of China
| | - Tao Sun
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, 300072 People’s Republic of China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, People’s Republic of China
| | - Shuo Chen
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, People’s Republic of China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, 300072 People’s Republic of China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, People’s Republic of China
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, 300072 People’s Republic of China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, People’s Republic of China
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, People’s Republic of China
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47
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Sun T, Pei G, Wang J, Chen L, Zhang W. A novel small RNA CoaR regulates coenzyme A biosynthesis and tolerance of Synechocystis sp. PCC6803 to 1-butanol possibly via promoter-directed transcriptional silencing. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:42. [PMID: 28239414 PMCID: PMC5319066 DOI: 10.1186/s13068-017-0727-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 02/09/2017] [Indexed: 05/24/2023]
Abstract
BACKGROUND Microbial small RNAs (sRNAs) have been proposed as valuable regulatory elements for optimizing cellular metabolism for industrial purposes. However, little information is currently available on functional relevance of sRNAs to biofuels tolerance in cyanobacteria. RESULTS Here, we described the identification and functional characterization of a novel 124 nt sRNA Ncl1460 involved in tolerance to biofuel 1-butanol in Synechocystis sp. PCC 6803. The expression of Ncl1460 was verified by blotting assay and its length was determined through 3' RACE. Further analysis showed that Ncl1460 was a negative regulator of slr0847 (coaD) and slr0848 operon responsible for coenzyme A (CoA) synthesis possibly via promoter-directed transcriptional silencing mechanisms which has been widely discovered in eukaryote; thus Ncl1460 was designated as CoaR (CoA Biosynthesis Regulatory sRNA). The possible interaction between CoaR and target genes was suggested by CoA quantification and green fluorescent protein assays. Finally, a quantitative proteomics analysis showed that CoaR regulated tolerance to 1-butanol possibly by down-regulating CoA biosynthesis, resulting in a decrease of fatty acid metabolism and energy metabolism. CONCLUSIONS As the first reported sRNA involved CoA synthesis and 1-butanol tolerance in cyanobacteria, this study provides not only novel insights in regulating mechanisms of essential pathways in cyanobacteria, but also valuable target for biofuels tolerance and productivity modifications.
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Affiliation(s)
- Tao Sun
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072 People’s Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072 People’s Republic of China
| | - Guangsheng Pei
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072 People’s Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072 People’s Republic of China
| | - Jiangxin Wang
- Shenzhen Engineering Lab for Marine Algal Biotechnology, College of Life Science, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072 People’s Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072 People’s Republic of China
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072 People’s Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072 People’s Republic of China
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, People’s Republic of China
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48
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Woo JM, Kim JW, Song JW, Blank LM, Park JB. Activation of the Glutamic Acid-Dependent Acid Resistance System in Escherichia coli BL21(DE3) Leads to Increase of the Fatty Acid Biotransformation Activity. PLoS One 2016; 11:e0163265. [PMID: 27681369 PMCID: PMC5040553 DOI: 10.1371/journal.pone.0163265] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Accepted: 09/05/2016] [Indexed: 01/29/2023] Open
Abstract
The biosynthesis of carboxylic acids including fatty acids from biomass is central in envisaged biorefinery concepts. The productivities are often, however, low due to product toxicity that hamper whole-cell biocatalyst performance. Here, we have investigated factors that influence the tolerance of Escherichia coli to medium chain carboxylic acid (i.e., n-heptanoic acid)-induced stress. The metabolic and genomic responses of E. coli BL21(DE3) and MG1655 grown in the presence of n-heptanoic acid indicated that the GadA/B-based glutamic acid-dependent acid resistance (GDAR) system might be critical for cellular tolerance. The GDAR system, which is responsible for scavenging intracellular protons by catalyzing decarboxylation of glutamic acid, was inactive in E. coli BL21(DE3). Activation of the GDAR system in this strain by overexpressing the rcsB and dsrA genes, of which the gene products are involved in the activation of GadE and RpoS, respectively, resulted in acid tolerance not only to HCl but also to n-heptanoic acid. Furthermore, activation of the GDAR system allowed the recombinant E. coli BL21(DE3) expressing the alcohol dehydrogenase of Micrococcus luteus and the Baeyer-Villiger monooxygenase of Pseudomonas putida to reach 60% greater product concentration in the biotransformation of ricinoleic acid (i.e., 12-hydroxyoctadec-9-enoic acid (1)) into n-heptanoic acid (5) and 11-hydroxyundec-9-enoic acid (4). This study may contribute to engineering E. coli-based biocatalysts for the production of carboxylic acids from renewable biomass.
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Affiliation(s)
- Ji-Min Woo
- Department of Food Science & Engineering, Ewha Womans University, Seoul, 120-750, Republic of Korea
| | - Ji-Won Kim
- Department of Food Science & Engineering, Ewha Womans University, Seoul, 120-750, Republic of Korea
| | - Ji-Won Song
- Department of Food Science & Engineering, Ewha Womans University, Seoul, 120-750, Republic of Korea
| | - Lars M. Blank
- Institute of Applied Microbiology - iAMB, Aachen Biology and Biotechnology - ABBt, RWTH Aachen University, Aachen, Germany
| | - Jin-Byung Park
- Department of Food Science & Engineering, Ewha Womans University, Seoul, 120-750, Republic of Korea
- * E-mail:
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49
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Zhang J, Caiyin Q, Feng W, Zhao X, Qiao B, Zhao G, Qiao J. Enhance nisin yield via improving acid-tolerant capability of Lactococcus lactis F44. Sci Rep 2016; 6:27973. [PMID: 27306587 PMCID: PMC4910042 DOI: 10.1038/srep27973] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 05/27/2016] [Indexed: 11/09/2022] Open
Abstract
Traditionally, nisin was produced industrially by using Lactococcus lactis in the neutral fermentation process. However, nisin showed higher activity in the acidic environment. How to balance the pH value for bacterial normal growth and nisin activity might be the key problem. In this study, 17 acid-tolerant genes and 6 lactic acid synthetic genes were introduced in L. lactis F44, respectively. Comparing to the 2810 IU/mL nisin yield of the original strain F44, the nisin titer of the engineered strains over-expressing hdeAB, ldh and murG, increased to 3850, 3979 and 4377 IU/mL, respectively. These engineered strains showed more stable intracellular pH value during the fermentation process. Improvement of lactate production could partly provide the extra energy for the expression of acid tolerance genes during growth. Co-overexpression of hdeAB, murG, and ldh(Z) in strain F44 resulted in the nisin titer of 4913 IU/mL. The engineered strain (ABGL) could grow on plates with pH 4.2, comparing to the surviving pH 4.6 of strain F44. The fed-batch fermentation showed nisin titer of the co-expression L. lactis strain could reach 5563 IU/mL with lower pH condition and longer cultivation time. This work provides a novel strategy of constructing robust strains for use in industry process.
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Affiliation(s)
- Jian Zhang
- Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.,Key Laboratory of Systems Bioengineering, Ministry of Education Tianjin, 300072, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Qinggele Caiyin
- Key Laboratory of Systems Bioengineering, Ministry of Education Tianjin, 300072, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Wenjing Feng
- Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.,Key Laboratory of Systems Bioengineering, Ministry of Education Tianjin, 300072, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Xiuli Zhao
- Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.,Key Laboratory of Systems Bioengineering, Ministry of Education Tianjin, 300072, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Bin Qiao
- Key Laboratory of Systems Bioengineering, Ministry of Education Tianjin, 300072, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Guangrong Zhao
- Key Laboratory of Systems Bioengineering, Ministry of Education Tianjin, 300072, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Jianjun Qiao
- Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.,Key Laboratory of Systems Bioengineering, Ministry of Education Tianjin, 300072, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
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50
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Meyer MM. The role of mRNA structure in bacterial translational regulation. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 8. [PMID: 27301829 DOI: 10.1002/wrna.1370] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 05/12/2016] [Accepted: 05/16/2016] [Indexed: 01/08/2023]
Abstract
The characteristics of bacterial messenger RNAs (mRNAs) that influence translation efficiency provide many convenient handles for regulation of gene expression, especially when coupled with the processes of transcription termination and mRNA degradation. An mRNA's structure, especially near the site of initiation, has profound consequences for how readily it is translated. This property allows bacterial gene expression to be altered by changes to mRNA structure induced by temperature, or interactions with a wide variety of cellular components including small molecules, other RNAs (such as sRNAs and tRNAs), and RNA-binding proteins. This review discusses the links between mRNA structure and translation efficiency, and how mRNA structure is manipulated by conditions and signals within the cell to regulate gene expression. The range of RNA regulators discussed follows a continuum from very complex tertiary structures such as riboswitch aptamers and ribosomal protein-binding sites to thermosensors and mRNA:sRNA interactions that involve only base-pairing interactions. Furthermore, the high degrees of diversity observed for both mRNA structures and the mechanisms by which inhibition of translation occur have significant consequences for understanding the evolution of bacterial translational regulation. WIREs RNA 2017, 8:e1370. doi: 10.1002/wrna.1370 For further resources related to this article, please visit the WIREs website.
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