A New Antibiotic K-52 B

Abstract

A new antibiotic K-52 B, different from K-52 A, was isolated from the culture broth of Streptoverticillium roseoverticillatum subsp. albosporum, strain No. K-52. The antibiotic K-52 B was thought to be a similar saccharide to K-52 A from its physicochemical properties but differed from K-52 A in the presence of nitrogen content. Antibiotic K-52 B inhibited the growth of Gram-positive and Gram-negative bacteria, including Pseudomonas aeruginosa on a chemically defined medium. The growth inhibition was, however, reversed by L-glutamine, L-glutamic acid, L-asparagine and L-aspartic acid.