THE EFFECT OF CERULENIN ON THE PRODUCTION OF ESPERAMICIN-A(1) BY ACTINOMADURA-VERRUCOSOSPORA

Addition of cerulenin (0.25-1.0 mM) to cultures of Actinomadura verruc osospora before the onset of esperamicin synthesis inhibited the produ ction of esperamicin A1 by the microorganism. This result indicates th at esperamicin A1 is biosynthesized in part by the polyketide pathway. Addition of cerulenin to the cultures during the active production ph ase led to a net decreased in esperamicin A1 production. The C-14-acet ate labeling pattern of esperamicin A1 in the cultures with or without addition of cerulenin at the active production phase also demonstrate d the instability of esperamicin A1 in the fermentation. This suggests that esperamicin A1 is unstable and degradation occurs during the act ive production phase. Addition of the neutral resin Diaion HP-20 (1%) to the fermentation enhanced the production of esperamicin A1 by 53%.