Abstract:
In this research, the kinetics of growth and the protease and amylase production by Aspergillusoryzae in solid state fermentation (SSF) were studied. These works were divided into 3 parts.In the first part, the appropriate ratio of tapioca pulp and soybean pulp in the substrate weredetermined. The results showed that 4 : 6 ratio of tapioca pulp and soybean pulp gave the highestprotease production. For the second part, the effects of temperature and substrate moisture contenton growth and enzyme production of A. oryzae were studied. The highest growth and protease andamylase production were found when A. oryzae was cultured at 30 OC with substrate moisturecontent of 60 percent. The results also showed that enzyme production were associated with itsgrowth. Finally, the mathematical parameters involving growth and enzyme production weredetermined. The maximum specific growth rate (Umax) and the maximum biomass concentration(Xmax) were obtained by fitting the experimental data with logistic growth model. The kinetic ofenzyme production was explained by growth associated model. The protease productioncoefficient (? ) and the amylase production coefficient (? ) were estimated. The correlationbetween temperature, substrate moisture content, and these kinetic parameters were explained bylognormal distribution model.