[Formation of new antibiotic, virenomycin, by a culture of Streptomyces virens sp. nev].

A culture of a new species Streptomyces virens was isolated from a soil sample. It produced an antibiotic designated as virenomycin. The antibiotic was mainly synthesized in the mycelium. Only insignificant amounts of it were found in the culture fluid. The optimal nutrient medium for production of virenomycin contained glycerol, soybean meal, ammonium sulphate, sodium chloride and calcium carbonate. Crystalline virenomycin had a comparatively low antitumor activity and narrow spectrum.