title: Inhibition of biofilm development and spoilage potential of Shewanella baltica by quorum sensing signal in cell-free supernatant from Pseudomonas fluorescens.
abstract: The objective of this study was to in vitro evaluate the effect of a cell-free supernatant (CFS) containing quorum sensing (QS) signal of Pseudomonas fluorescens on the growth, biofilm development and spoilage potential of Shewanella baltica, and preliminarily assess the interactive influences of various chemically synthesized autoinducers on spoilage phenotypes of S. baltica. PF01 strain isolated from spoiled Pseudosciaen crocea was identified P. fluorescens. The addition of 25% and 50% CFS to S. baltica culture had no effect on the growth rate during the lag and exponential phase, however, caused cell decline during the stationary phase. The presence of CFS from P. fluorescens significantly inhibited biofilm development, and greatly decreased the production of trimethylamine (TMA) and biogenic amino in S. baltica. Various signal molecules of QS in the CFS of P. fluorescens culture were detected, including seven N-acyl-l-homoserine lactones (AHLs), autoinducer-2 (AI-2) and two diketopiperazines (DKPs). Exogenous supplement of synthesized seven AHLs containing in the CFS decreased biofilm formation and TMA production in S. baltica, while exposure to exogenous cyclo-(l-Pro-l-Leu) was showed to promote spoilage potential, which revealed that S. baltica also sense the two QS molecules. Furthermore, the stimulating effect of cyclo-(l-Pro-l-Leu) was affected when AHL was simultaneously added, suggesting that the inhibitory activity of spoilage phenotypes in S. baltica might be attributed to a competitive effect of these QS compounds in the CFS of P. fluorescens. The present studies provide a good basis for future research on the role of QS in the regulation of spoilage microbial flora.
authors.affiliation: College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang, Province 310018, China.
authors.forename: Aifei
authors.initials: A
authors.lastname: Zhao
authors.affiliation: College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang, Province 310018, China. Electronic address: junlizhu0305@163.com.
authors.forename: Junli
authors.initials: J
authors.lastname: Zhu
authors.affiliation: College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang, Province 310018, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Ye
authors.affiliation: College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang, Province 310018, China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Ge
authors.affiliation: College of Chemistry, Bohai University, Jinzhou, Liaoning, Province 121013, China.
authors.forename: Jianrong
authors.initials: J
authors.lastname: Li
mesh_terms: D000818:Animals; D018441:Biofilms / Q000254:growth & development*; D002474:Cell-Free System / Q000382:microbiology; D054659:Diketopiperazines / Q000378:metabolism*; D005399:Fishes / Q000382:microbiology; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000382:microbiology; D006714:Homoserine / Q000031:analogs & derivatives* / Q000378:metabolism; D007783:Lactones / Q000378:metabolism*; D008744:Methylamines / Q000378:metabolism; D011551:Pseudomonas fluorescens / Q000378:metabolism*; D053038:Quorum Sensing / Q000502:physiology*; D017747:Seafood / Q000382:microbiology; D020592:Shewanella / Q000254:growth & development*; D015398:Signal Transduction
chemical_list: D054659:Diketopiperazines; D007783:Lactones; D008744:Methylamines; C091088:N-octanoylhomoserine lactone; D006714:Homoserine; C023336:trimethylamine
keywords: Autoinducers; Biofilm; Cell-free supernatant; Pseudomonas fluorescens; Quorum sensing; Shewanella baltica; Spoilage