Positive Regulation of Spoilage Potential and Biofilm Formation in Shewanella baltica OS155 via Quorum Sensing System Composed of DKP and Orphan LuxRs
Positive Regulation of Spoilage Potential and Biofilm Formation in Shewanella baltica OS155 via Quorum Sensing System Composed of DKP and Orphan LuxRs
复制标题
通过 DKP 和孤儿 LuxR 组成的群体感应系统对 Shewanella baltica OS155 的腐败潜力和生物膜形成进行积极调节
DOI：
10.3389/fmicb.2019.00135
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发表时间：
2019-02-05
影响因子：
5.2
通讯作者：
Fu, Linglin
中科院分区：
文献类型：
--
作者：
Wang, Yanbo;Wang, Feifei;Fu, Linglin
从表型的角度研究了群体感应（Quorum sensing，QS）系统对波罗的海希瓦氏菌腐败和生物膜形成的调控作用，但具体机制尚不清楚。本研究采用超高效液相色谱-串联质谱法检测QS自诱导物，并通过一系列候选基因的自调控实验，获得了细胞密度依赖性luxR型基因。baltica OS 155（大黄鱼的SSO）。通过体外结合试验揭示了cyclo-（L-Pro-L-Phe）（PP）与LuxR 01和LuxR 02蛋白之间的直接相互作用。缺失luxR型基因（luxR 01和luxR 02）可降低沙门氏菌的腐败潜力和生物膜形成。Baltica OS 155在不同程度上。转录分析和qRT-PCR验证表明，腐败和生物膜相关基因torS，speF和pomA在luxR 01和luxR 02缺失菌株中下调。此外，外源PP促进腐败潜力和生物膜的形成，这可以减弱luxR 01或luxR 02缺失。我们的结果揭示了一个明确的QS系统，该系统使用PP作为自诱导物，并使用两个孤儿LuxR作为受体，通过S中相应基因的转录调节来正向调节腐败能力和生物膜形成。baltica OS 155，为涉及QS体系的海产品保鲜提供了潜在的特定目标。
The spoilage potential and biofilm formation of Shewanella baltica are reported to be regulated by Quorum sensing (QS) system from the phenotype point of view, but the specific mechanism is not fully understood. In the present study, the QS autoinducers were detected by UHPLC-MS/MS, cell density-dependent luxR-type genes were obtained through autoregulation experiments among a series of candidates in S. baltica OS155 (The SSO of large yellow croaker). The direct interaction between cyclo-(L-Pro-L-Phe) (PP) and LuxR01 as well as LuxR02 proteins was revealed via in vitro binding assay. Deletion of luxR-type genes (luxR01 and luxR02) impaired spoilage potential and biofilm formation of S. baltica OS155 in various degrees. Transcriptional analysis and qRT-PCR validation showed that spoilage and biofilm-related genes torS, speF, and pomA were down-regulated in luxR01 and luxR02 deletion strains. In addition, exogenous PP promoted spoilage potential and biofilm formation, which could be attenuated by luxR01 or luxR02 deletion. Our results revealed an explicit QS system employing PP as autoinducer and two orphan LuxRs as receptors which positively regulated spoilage capacity and biofilm formation via transcriptional regulation of corresponding genes in S. baltica OS155, which provides potential specific targets for seafood preservation involving QS system.