Macarbomycin, a new antibiotic containing phosphorus.

Sir: During screening studies of antibiotics active against Staphylococcus aureus 193 (a resistant strain to tetracyclines), a watersoluble and acidic antibiotic was obtained in 1964. It was extracted mainly from the solid portion including mycelia of a cultured broth of a streptomyces, designated as No. C715-7. The strain was isolated from a soil sample collected in Geneva, Switzerland, and classified as Streptomyces phaeochromogenes. The antibiotic, named macarbomycin because of its macromolecular nature, yielded sugars in the acid hydrolysate. Macarbomycin contains phosphorus and is related to moenomycin^ and prasinomycin2), but can be differentiated from these antibiotics by paper and thin-layer chromatography and also by the fact that the acid hydrolysate of macarbomycin does not contain 6deoxyglucosamine. Added to animal feed, macarbomycin exhibited an excellent effect on growth promotion. In the present paper, the production, isolation, physico-chemical and biological properties are described. The mechanism of action was previously reported by J. Suzuki et al.3) of the Institute of Microbial Chemistry, who observed that macarbomycin inhibits cell wall synthesis, especially the process of polymerization of N-acetylglucosamine and muramic acid pen-