Hygromycin and epihygromycin from a bacterium, Corynebacterium equi No. 2841.

A newly isolated bacterium which produces antibacterial substances as below was taxonomically characterized and identified with Corynebacterium equi. The major antibiotic produced was determined to be hygromycin by direct comparison. The minor component, newly named epihygromycin was proved to be an epimer of hygromycin by spectrosocopic evidences and by chemical conversions. The presence of epihygromycin in the metabolites of Streptomyces noboritoensis (reported to be a hygromycin producer) was also observed.