Effects of Nutrients on Quorum Signals and Secondary Metabolite Productions of Burkholderia sp. 033

摘要

Several bioactive metabolites, including pyrrolnitrin, N-acylhomoserine lactones, and polyhydroxyalkanoates wereisolated from Burkholderia sp. 033. Effects of variousnutrients, including sugars, gluconolactone, glycerol,tryptophan, chloride, and zinc were investigated in relationto the production of these metabolites. Logarithmic increaseof pyrrolnitrin was observed between 2-5 days andreached a maximum at 7-10 days. Tryptophan concentrationreached the maximum at 3 days, whereas 7-chlorotryptophanwas gradually increased throughout the studies. Amongvarious carbon sources, gluconolactone, trehalose, andglycerol enhanced pyrrolnitrin production, whereas stronginhibitory effects were found with glucose. Relativeconcentrations of pyrrolnitrin and its precursors were inthe order of pyrrolnitrin dechloroaminopyrrolnitrin oraminopyrrolnitrin throughout the experiments. Amongthree N-acylhomoserine lactones, the N-octanoyl analogwas the most abundant quorum sensing signal, of which,the concentrations reached the maximum in 2-3 days,followed by a rapid dissipation to trace level. No significantchanges in pyrrolnitrin biosynthesis were observed by externaladdition of N-acylhomoserine lactones. Polyhydroxyalkanoatesaccumulated up to 3-4 days and decreased slowly thereafter.According to the kinetic analyses, no strong correlations werefound between the levels of pyrrolnitrin, N-acylhomoserinelactones, and polyhydroxyalkanoates.