IM-2, A BUTYROLACTONE AUTOREGULATOR, INDUCES PRODUCTION OF SEVERAL NUCLEOSIDE ANTIBIOTICS IN STREPTOMYCES SP FRI-5

IM-2 is one of the butyrolactone autoregulators of Streptomyces, which triggers production of a blue pigment in Streptomyces sp. FRI-5 at a concentration of 0.6 ng/ml. In the absence of IM-2, Streptomyces sp. FRI-5 was found to produce D-Cycloserine. However, the addition of IM-2 at 5-h cultivation stopped both growth and D-CyCloserine production, and instead induced production of several different antibiotics. The IM-2-induced antibiotics were isolated from the culture broth, and assigned as the nucleoside antibiotics, showdomycin and minimycin. Therefore, IM-2 was concluded to be a global regulator of secondary metabolism, which not only induced the production of nucleoside antibiotics but also suppressed D-cycloserine production.