Features of the SprlR Quorum Sensing System of <i>Serratia proteamaculans </i>94and Its Participation in the Regulation of Cellular Processes
The quorum sensing (QS) regulatory system of the psychrotrophic strain <i>Serratic proteamaculans </i>94 was investigated. A mutant was constructed with inactivated gene <i>sprR </i>encoding the regulatory receptor protein SprR. Inactivation of this gene was shown to affect the composition of fatty acids synthesized by <i>S</i>. <i>proteamaculans </i>94, and did not affect the N-acyl-L-homoserine-lactones (AHL) synthesis, the activities of extracellular proteases, chitinases. hemolysins, swimming motility of cells and suppression of mycelium growth of fungal plant pathogens by volatile compounds emitted by this strain. Inactivation of the <i>sprI </i>gene (but not the <i>sprR </i>gene) reduced the biofilm formation which increased when exogenous AHL was added to the culture. The comparative proteomic analysis of cells of the parent strain and mutant strains with inactivated <i>sprI </i>and <i>sprR </i>genes showed that the expression of 30 proteins in <i>S. proteamaculans </i>94 is affected by SprIR quorum sensing system.