Regulatory mutants ofStreptomyces cinnamonensisproducing monensin A

Abstract

We prepared mutants of Streptomyces cinnamonensis resistant to amino acid analogues: 2‐aminobutyrate, norvaline, norleucine, 2‐amino‐3‐chlorobutyrate and ethionine. The regulatory mutants were studied as to their production of oligoketide antibiotics, monensins A and B, as dependent on the formation of valine which is a precursor of the butyrate building unit of monensin A. Strains resistant to both 2‐amino‐3‐chlorobutyrate and norleucine exhibited an increased production of monensin A from 50% to 90–93% of total monensins.