1961 Volume 14 Issue 5 Pages 255-263
A crystalline antibiotic, active against gram-positive bacteria and mycobacteria, has been isolated from the broth of a strain of Streptomyces. This strain, which indexed H-690 in our culture collection, has been isolated from a soil sample collected from Shioya, Kobe. The chemical and physical properties show that the antibiotic is similar to thiostrepton,** isolated by Vandeputte, et al.1), the only difference consisting in the absence of leucine (or isoleucine) in its amino acid composition. Moreover, it doer not correspond with its paper chromatographic behavior to thiostrepton. The new antibiotic has been therefore designated as siomycin.
In the present paper, we intend to describe the antibiotic-producing organism and to, report the isolation and the principal characteristics of siomycin which presents some thiostrepton-like properties. The comparison is carried out with a sample of thiostrepton kindly supplied by Dr. Vandeputte.
