Effects of quorum quenching by AHL lactonase on AHLs, protease, motility and proteome patterns in Aeromonas veronii LP-11.

Food spoilage by some bacteria is reported to be regulated by quorum sensing (QS). In this study, a quorum quenching approach was used to investigate the QS regulated phenotypes (growth, protease and motility) and proteins expression in of Aeromonas veronii LP-11, which is a specific spoilage organism of sturgeon. AHL lactonase AiiAAI96 from Bacillus quenched the QS system, probably by enzymatically inactivating the AHLs produced by A. veronii LP-11. After AiiAAI96 treatment, the protease and motility activities of A. veronii LP-11 were reduced, but cell growth was not affected. Proteome analysis revealed thirty-two proteins that were differentially expressed within cells treated with AiiAAI96 at early stationary phase, and that are functionally involved in metabolite transport, amino acid metabolism, central metabolism, respiration, transcription and translation, suggesting that QS may globally coordinate the metabolic processes within A. veronii LP-11 cells. Some of these QS regulated proteins were identified to be potentially participated in nutrient acquirement from environment and spoilage behavior of the organism. Indeed, AiiAAI96 treatment inhibited the spoilage progress of vacuum-packaged sturgeon stored at 4°C. These results highlight that the QS is a major metabolism regulator within A. veronii LP-11 cells and participates in sturgeon spoilage.