Isolation of a new peptide antibiotic complex, B-43. Studies on antibiotics from the genus Bacillus. XV.

Abstract
A new peptide antibiotic complex, B-43, active against gram-positive and gram-negative bacteria, was isolated from a strain of B. circulans. This antibiotic contains aspartic acid, valine, isoleucine, leucine, phenylalanine and 2,4-diaminobutyric acid. It seems to be related to polypeptin and antibiotic complex 4205, but differs in that it contains aspartic acid residue.