Effect of the Added Acyl Homoserine Lactones on Separated Free-Living Marine Bacteria as a Model of Quorum Sensing

Quorum sensing is a communication system by which bacteria use signal molecules to induce physiological response. In natural marine environments, quorum suspected occur in regions with high cell densities. Free-living bacteria, however, are largely believed exist at concentrations too low make of density-dependent quorum-sensing system. Due so-called ‘free-living’ inhabiting gels composed exopolymeric substances occurring an operationally defined colloidal fraction, it possible that would also this fraction. study, signaling were collected from water, separated, and concentrated as some organic matter. Their identification Agrobacterium tumefaciens assay indicated the presence AHLs. fall 2002 spring 2003, free-living (single cells) fraction bacterioplankton was sampled separated. Various AHLs added these disperse populations (109 cells/L). The studied bacterial communities responded change thymidine incorporation. results discussed existence active reaction even sparse gels. That there response so great significance for environmental sciences.