TARGET RANGE OF ZWITTERMICIN-A, AN AMINOPOLYOL ANTIBIOTIC FROM BACILLUS-CEREUS

Zwittermicin A is a novel antibiotic produced by Bacillus cereus UW85, which suppresses certain plant diseases in the laboratory and in the field. We developed a rapid method for large-scale purification of zwi ttermicin A and then studied the in vitro activity of zwittermicin A a gainst bacteria, fungi, and protists. Zwittermicin A was highly active against the Oomycetes and their relatives, the algal protists, and ha d moderate activity against diverse Gram-negative bacteria and certain Gram-positive bacteria as well as against a wide range of plant patho genic fungi. Zwittermicin A was more active against bacteria and fungi at pH 7-8 than at pH 5-6. When zwittermicin A was combined with kanos amine, another antibiotic produced by B. cereus, the two acted synergi stically against Escherichia coli and additively against Phytophthora medicaginis, an Oomycete. The results indicate that there are diverse potential applications of this new class of antibiotic.