冲绳海槽热液区和南海冷泉区副球菌属细菌群体感应及代谢特征研究OA

In response to the issues of quorum sensing(QS)and quorum quenching(QQ)of bacteria belonging to the genus Paracoccus in hydrothermal vents and cold seeps,as well as the regulation of bacterial physiological metabolic processes by QS,the study aims to unveil the diversity of QS active Paracoccus isolations in the hydrothermal vents of the Okinawa Trough and cold seeps of the South Chi-na Sea,and investigate the regulatory role of QS in the physiological metabolism of typical Paracoccus strains.Using Agrobacterium tumefaciens A136 as reporter strain,AHL-producion and degradation ac-tivities were screened by high-throughput method based on β-galactosidase(LacZ)reporter gene in Paracoccus isolated from hydrothermal vents in Okinawa Trough and cold seeps in South China Sea.The metabolic diversities of QS strains were detected,such as biofilm production extracellular enzymatic activities,sulfur-oxidizing ability and the ability of degrading DMSP.By adding AHLs to cultures the QS strains,the DMSP degrading was detected to verify the process of DMSP degrading influenced by QS.By supplementing culture media with AHLs,the regulatory role of quorum sensing in the growth of representative strains was investigated.In the 28 Paracoccus strains isolated from hydrothermal vents in Okinawa Trough and cold seeps in South China Sea,7 isolates had AHL-producing activities,which belonged to 5 different species,Paracoccus amoyensis,Paracoccus marcusii,Paracoccus oceanense,Paracoccus onubensis and Paracoccus sediminilitoris.4 isolates had AHL-degrading activi-ties,which belonged to 3 species,P.amoyensis,P.marcusii and P.oceanense.It was found that P.amoyensis T3'119,T3'120 and T3'131 showed phosphatase activity,and the strain T3'131 showed the ability of sulfur-oxidizing;P.onubensis YL619 showed α-glucosidase,β-glucosidase and phosphatase ac-tivities,and the ability of DMSP degrading.Low concentrations of C10-HSL(≤20 μmol/L)showed no effect on the growth of strains T3'120 and T3'131.However,medium and high concentrations of C10-HSL(≥40 μmol/L)reduced the final cell density at stationary phase while prolonging the logarithmic growth phase in both strains.In contrast,exogenous AHL supplementation exhibited no observable im-pact on the growth of strain YL619.The diversity and complexity of QS and QQ strains in Paracoccus from hydrothermal fields of the Okinawa Trough and cold seeps of the South China Sea are abundant,and the physiological metabolism of hydrothermal fields and cold seeps could be regulated by QS,laying a foundation for further exploration of their adaptation mechanisms in deep-sea chemical energy synthe-sis ecosystem.