Identification of two metabolites induced by a butyrolactone autoregulator IM-2 in Streptomyces sp. FRI-5

Abstract

IM-2, one of the butyrolactone autoregulators of Streptomyces, triggers blue pigment production in Streptomyces sp. FRI-5 at a concentration of 0.6 ng/ml. Two IM-2-induced metabolites were identified by comparison of the HPLC profiles of extracellular metabolites produced in the absence and presence of IM-2. The two compounds were purified to homogeneity from the culture broth, and assigned as tryptophol and guanosine, respectively. With respect to the IM-2-induced production of guanosine, the intracellular and extracellular nucleotide contents were investigated in the absence and presence of IM-2. No difference in nucleotide content, including that of ppGpp, was observed, indicating that ppGpp does not participate in the induction pathway of IM-2. It was therefore concluded that IM-2 is an independent regulator of Streptomyces metabolism, which not only induces blue pigment but also affects metabolism of tryptophan and guanosine. © 1994.