COMPARISON OF SPORULATION OF PAECILOMYCES-FARINOSUS AND BEAUVERIA-BASSIANA IN BATCH AND FED-BATCH CULTURE

The entomogenous fungi, Paecilomyces farinosus and Beauveria bassiana, were grown in batch and in glucose- and ammonium-limited fed-batch culture. In batch cultures grown on complex or minimal media, P. farinosus and B. bassiana produced blastospores in the exponential and deceleration phases of growth, and B. bassiana, but not P. farinosus, also formed spores during the stationary phase. In both glucose- and ammonium-limited fed-batch cultures (complex and minimal media for glucose, minimal medium for ammonium), blastospore concentration in P. farinosus, but not B. bassiana, was inversely related to dilution rate. However, compared with batch cultures grown on complex medium, only glucose-limited fed-batch cultures of P. farinosus grown on minimal medium gave enhanced production of blastospores. Unbalanced growth occurred in ammonium-limited fed-batch cultures of both fungi.