THE INFLUENCE OF DISSOLVED-OXYGEN TENSION ON THE SYNTHESIS OF THE ANTIBIOTIC DIFFICIDIN BY BACILLUS-SUBTILIS

The antibiotic, difficidin, and its hydroxylated derivative, oxydiffic idin, were synthesized by cultures of Bacillus subtilis grown on a com plex medium. Maximum titers of about 200 and 130 mg/L, respectively, w ere obtained. In fermentations where the dissolved oxygen tension (DOT ) was controlled, the maximum specific growth rate was only reduced be low 5% air saturation. DOT had little effect on the volumetric rate of synthesis of oxydifficidin but greatly influenced the rate for diffic idin, which was reduced at DOT values below 40% air saturation. (C) 19 94 John Wiley and Sons, Inc.