Abstract
1. Four strains of Actinomyces were isolated. They grew well and degradated bile acid extremely well in a synthetic culture medium in which the only source of carbon is free bile acid or the only source of carbon and nitrogen is glyco-cholic acid. 2. When cholic acid was used as a bile acid, Actinomyces No. 1164, which is one of the four strains, yielded two new acids with m.γ. 280-282° (decomp.) and with m.p. 248° (decomp.). 3. Acid with m.p. 280-282° (decomp.) is probably a derivative of bisnorcholenic acid, because it yields methyl dehydrobisnorcholate by the treatments of hydrogenation, methyl esterification and oxidation.