Abstract

Growth of Gibberella fujikuroi on Amberlite, an inert support, and gibberellic acid (GA,) production was studied in glass columns under different conditions of temperature and water activity (a(w)). Maximum biomass concentration and GA(3) production were respectively 40 (mg/g inert support) and 0.73 (mg/g inert support). While high specific growth rates were obtained, low initial nitrogen resulted in low biomass concentrations. Maximum GA(3) (31 degrees C, a(w)=0.985) was not produced by the maximum concentration of biomass (25 degrees C, a(w)=0.992). Peaks in the rate curves of either outlet gas, CO2 or O-2 occurred on exhaustion of urea indicating, for future works, just when to feed the culture additional nitrogen. (C) 2000 Elsevier Science Ltd. All rights reserved.