Alisamycin is a new member of the manumycin group of antibiotics produced by Streptomyces sp. HIL Y-88,31582, which taxonomically appears to be Streptomyces actuosus. Alisamycin is active against Gram-positive bacteria and fungi, and has a weak antitumour activity.In the course of screening for new bioactive metabolites from actinomycetes, we detected a new member of the manumycin group of antibiotics which we named alisamycin. Other members of this group include manumycin, asukamycin, U-56,407, U-62162 and colabomycin. Alisamycin (1) was detected by bioautography using TLC plates. In this paper, we present the taxonomy of the producing organism Streptomyces sp. Y-88,31582 together with the fermentative production, isolation and biological activity of alisamycin. The structure elucidation will be presented elsewhere.