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New temperature-switchable acyl homoserine lactone-regulated expression vector. Appl Microbiol Biotechnol 2023; 107:807-818. [PMID: 36580089 DOI: 10.1007/s00253-022-12341-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 12/30/2022]
Abstract
Bacterial expression systems play an indispensable role in the biosynthesis of recombinant proteins. Different proteins and the tasks associated with them may require different systems. The purpose of this work is to make an expression vector that allows switching on and off the expression of the target gene during cell incubation. Several expression vectors for use in Escherichia coli cells were developed using elements of the luxR/luxI type quorum sensing system of psychrophilic bacterium Aliivibrio logei. These vectors contain A. logei luxR2 and (optionally) luxI genes and LuxR2-regulated promoter, under the control of which a target gene is intended to be inserted. The synthesis of the target protein depends directly on the temperature: gene expression starts when the temperature drops to 22 °C and stops when it rises to 37 °C, which makes it possible to fix the desired amount of the target protein in the cell. At the same time, the expression of the target gene at a low temperature depends on the concentration of the autoinducer (L-homoserine N-(3-oxohexanoyl)-lactone, AI) in the culture medium in a wide range from 1 nM to 10 μM, which makes it possible to smoothly regulate the rate of target protein synthesis. Presence of luxI in the vector provides the possibility of autoinduction. Constructed expression vectors were tested with gfp, ardA, and ardB genes. At maximum, we obtained the target protein in an amount of up to 33% of the total cellular protein. KEY POINTS: • A. logei quorum sensing system elements were applied in new expression vectors • Expression of target gene is inducible at 22 °C and it is switched off at 37 °C • Target gene expression at 22 °C is tunable by use different AI concentrations.
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Yu Y, Li H, Wang Y, Zhang Z, Liao M, Rong X, Li B, Wang C, Ge J, Zhang X. Antibiotic resistance, virulence and genetic characteristics of Vibrio alginolyticus isolates from aquatic environment in costal mariculture areas in China. MARINE POLLUTION BULLETIN 2022; 185:114219. [PMID: 36335689 DOI: 10.1016/j.marpolbul.2022.114219] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 10/03/2022] [Indexed: 06/16/2023]
Abstract
Vibrio alginolyticus has been the second most common Vibrio species in the world and mainly grows in the ocean or estuary environment, which can induce epidemics outbreaks under marine organisms, and causing serious economic losses in aquaculture industry. In this study, the genetic populations and evolutionary relationship analysis of V. alginolyticus isolated from different geographical locations in China with typical interannual differences were exhibited originally genetic diversity. Then the virulence genes prevalence, antibiotic resistance phenotype, and antimicrobial resistance genes risk diversity of V. alginolyticus were analyzed by phenotypic and molecular typing methods. And they were complex correlations among antibiotic phenotypes, resistance and virulence genes under different genotype of V. alginolyticus. The results provide a theoretical foundation for further understanding the genetic and metabolic diversity among V. alginolyticus in China, and lay a theoretical foundation for the transmission risk assessment and regional diagnosis of Vibrio in aquatic animals.
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Affiliation(s)
- Yongxiang Yu
- Key Laboratory of Maricultural Organism Disease Control, Yellow Sea Fisheries Research Institute, Chinese Academic of Fishery Sciences, Qingdao, PR China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, PR China.
| | - Hao Li
- Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, PR China.
| | - Yingeng Wang
- Key Laboratory of Maricultural Organism Disease Control, Yellow Sea Fisheries Research Institute, Chinese Academic of Fishery Sciences, Qingdao, PR China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, PR China.
| | - Zheng Zhang
- Key Laboratory of Maricultural Organism Disease Control, Yellow Sea Fisheries Research Institute, Chinese Academic of Fishery Sciences, Qingdao, PR China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, PR China.
| | - Meijie Liao
- Key Laboratory of Maricultural Organism Disease Control, Yellow Sea Fisheries Research Institute, Chinese Academic of Fishery Sciences, Qingdao, PR China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, PR China.
| | - Xiaojun Rong
- Key Laboratory of Maricultural Organism Disease Control, Yellow Sea Fisheries Research Institute, Chinese Academic of Fishery Sciences, Qingdao, PR China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, PR China.
| | - Bin Li
- Key Laboratory of Maricultural Organism Disease Control, Yellow Sea Fisheries Research Institute, Chinese Academic of Fishery Sciences, Qingdao, PR China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, PR China.
| | - Chunyuan Wang
- Key Laboratory of Maricultural Organism Disease Control, Yellow Sea Fisheries Research Institute, Chinese Academic of Fishery Sciences, Qingdao, PR China.
| | - Jianlong Ge
- Key Laboratory of Maricultural Organism Disease Control, Yellow Sea Fisheries Research Institute, Chinese Academic of Fishery Sciences, Qingdao, PR China.
| | - Xiaosong Zhang
- Key Laboratory of Maricultural Organism Disease Control, Yellow Sea Fisheries Research Institute, Chinese Academic of Fishery Sciences, Qingdao, PR China.
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Cai J, Hao Y, Xu R, Zhang Y, Ma Y, Zhang Y, Wang Q. Differential binding of LuxR in response to temperature gauges switches virulence gene expression in Vibrio alginolyticus. Microbiol Res 2022; 263:127114. [PMID: 35878491 DOI: 10.1016/j.micres.2022.127114] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 06/04/2022] [Accepted: 07/05/2022] [Indexed: 12/26/2022]
Abstract
Vibrio pathogens must cope with temperature changes for proper thermo-adaptation and virulence gene expression. LuxR is a quorum-sensing (QS) master regulator of vibrios, playing roles in response to temperature alteration. However, the molecular mechanisms how LuxR is involved in adapting to different temperatures in bacteria have not been precisely elucidated. In this study, using chromatin immunoprecipitation and nucleotide sequencing (ChIP-seq), we identified 272 and 22 enriched loci harboring LuxR-binding peaks at ambient temperature (30 ˚C) and heat shock (42 ˚C) in the Vibrio alginolyticus genome, respectively. Analysis with the MEME (multiple EM for motif elicitation) algorithm indicated that the binding motifs of LuxR varied from temperatures. Three novel binding regions (the promoter of orf00292, orf00397 and fadD) of LuxR were identified and verified that the rising temperature causes the decreasing binding affinity of LuxR to these promoters. Meanwhile, the expression of orf00292, orf00397 and fadD were regulated by LuxR. Moreover, the weak binding of LuxR to the promoter of extracellular protease (Asp) was attributed to the attenuated Asp expression at thermal stress conditions. Taken together, our study demonstrated distinct binding characteristics of LuxR in response to temperature changes, thus highlighting LuxR as a thermo-sensor to switch and control virulence gene expression in V. alginolyticus.
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Affiliation(s)
- Jingxiao Cai
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Yuan Hao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Rongjing Xu
- Yantai Tianyuan Aquatic Co. Ltd., Yantai, Shandong, China
| | - Yuanxing Zhang
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai 200237, China
| | - Yue Ma
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai 200237, China; Shanghai Collaborative Innovation Center for Biomanufacturing, 130 Meilong Road, Shanghai 200237, China
| | - Yibei Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai 200237, China.
| | - Qiyao Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai 200237, China; Shanghai Collaborative Innovation Center for Biomanufacturing, 130 Meilong Road, Shanghai 200237, China
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