Distribution of virginiae butanolides in antibiotic-producing actinomycetes, and identification of the inducing factor from Streptomyces antibioticus as virginiae butanolide A.

Abstract

In the course of screening for physiologically active compounds, we recently isolated inducing factors for virginiamycin production from Streptomyces virginiae^. The compounds, named virginiae butanolides A, B and C (VB-A, -B and -C), are all 2,3-disubstituted7-butyrolactones. Except B-factor and pamamycin, the structure of substituted ^-butyrolactone is common to inducing factors from Streptomyces, such as Afactor from Streptomyces griseus2 > B\ and factors from Streptomyces bikiniensis and Streptomyces cyaneofuscatus0. Therefore, we suspect that VB-like compounds may function generally as intra-or intercellular signal molecules, especially in antibiotic-producing species. In this paper, 1191 we report the distribution of VBs in several species of antibiotic-producing Streptomyces, and the isolation and structure of a inducing factor from one of the strains, Streptomyces antibioticus. Weselected 1 1 species of actinomycetes, one of Bacillus and one of Cephalosporium. Culture mediumfor these strains except for Cephalosporiumacremonium contains soybean meal 1%,. com steep liquor 1%, potato starch 1 %, NaCl 0.5%, K2HPO4 0.2% and MgSO4 0.05%. The medium described by Demain et alP was used for C. acremonium. For seed culture preparation, 20ml of the medium in 100-ml Erlenmeyer flasks was inoculated from slants, and incubated at 28C for 3 days on a reciprocating shaker (120spm).