Importance of growth form on production of hybrid antibiotic by Streptomyces lividans TK21 by fed-batch and continuous fermentation

A fermentation strategy, based on the controlled feeding of growth-limiting nutrients in order to maintain metabolic activity for extended periods, ha s been examined in the case of the production of a hybrid antibiotic by a t ransformed strain of Streptomyces lividans TK21. The fed-batch operation di d not improve the results obtained with batch operation. Continuous culture s on defined medium showed stable levels of biomass concentration, but anti biotic production ceased when continuous operation was started. The results obtained indicate the critical influence that morphology of the cell aggre gates has on metabolic activity. The antibiotic is produced only in culture conditions providing growth in compact mycelial pellets.