Effects of DKPs on Gene Expression of the Antibacterial Substances in Bacillus amyloliquefaciens Q-426

Objective: Bacillus amyloliquefaciens Q-426 could produce varieties of antifungal lipopeptides during its stationary growth process,including bacillomycin D,fengycin A and B.Effects of diketopiperazines(DKPs) as signal molecules of quorum sensing(QS) on the biosynthesis of above antifungal compounds were studied through real time fluorescent quantitative polymerase chain reaction(Real-time Q-PCR).Methods: DKPs at a final concentration of 5 mg/l were added to the culture broth of strain Q-426 which was incubated at 30℃ for 12 h.After continuing cultivation for 48 h,quantitative analysis of mRNA expression levels was carried out by Real-time Q-PCR.Result: DKPs could inhibit the expression of some genes related with the biosynthesis of antifungal lipopeptides.