Abstract:
This research aims to investigate heat transfer during solid state fermentation using rotating drumbioreactor. In the first part of this research, the effect of rotational speed and air velocity on growthand enzyme production by Aspergillus orytae during solid state fermentation in rotating drumbioreactor were studied. Tapioca pulp and soybean waste at the ratio of 4 : 6 was used as thesubstrate. The results showed that at air flow rate of 0.03 d s and the rotational speed of 5 rpm, thehighest growth of A. orytae was obtained with the highest biomass concentration of 769 mg/g totalsubstrate dry weight. At this operating condition, protease and amylase production were 18,638 and62,693 unit'g total substrate dry weight, respectively.In the second part of this research, a mathematical model describing heat transfer in rotating drumbioreactor was developed. The model predictions showed good agreement with the experimentresults for biomass concentration, substrate temperature and air temperature during fermentation.