Increased production of the antibiotic aurodox (X-5108) by aurodox-resistant mutants.

Conventional strain and media improvement techniques were of limited success in increasing yields of the antibiotic aurodox (X-5108) above 0.5 g/liter. Higher yields were obtained by reversion of a zero producer followed by the selection of mutants resistant to aurodox. Resistant strains of Streptomyces goldiniensis ATCC 21386 able to grow on 2 g/liter of aurodox produced greater than 2.5 g/liter of antibiotic. The rate of yield increase leveled off as the strains became resistant to greater than 2 g/liter of aurodox. These strains, in contrast to those sensitive to aurodox, gave a positive response to conventional mutagenic methods for further yield increases.