SQ 26, 180, A NOVEL MONOBACTAM. I

TAXONOMY, FERMENTATION AND BIOLOGICAL PROPERTIES

Abstract

Strains of Chromobacterium: violaceum, isolated from various environments, were found to produce a novel monocyclic β-lactam antibiotic. The antibiotic, SQ 26, 180 was weakly active against Gram-positive and Gram-negative bacteria with the exception of mutants hypersensitive to β-lactam antibiotics. The compound was highly stable to β-lactamases and acted as an inhibitor of the P99 enzyme from Enterobacter cloacae. SQ 26, 180 showed affinity for penicillin-binding proteins la, 4 and 5/6 of Escherichia coli and inhibited R61 DD-carboxypeptidase.