Theoretical study of the effects of water content and temperature on solid-state fermentation using MATLAB

Abstract

Microbial growth can be effected by growth conditions such as temperature, water content, oxygen and carbon dioxide concentrations. This study investigated the effects of input air velocities on water content, temperature and biomass concentration at any height of the packed column. Mathematical modeling was performed based on heat and mass balances detecting those parameters during the 100 hours fermentation period. MATLAB^TM was applied to solve the equations in one-dimension. The study shows that temperature and water content crucially affect the microbial growth. The fungi can grow very well at temperature 305-310 ºK. However, the growth will decrease when the system temperature is out of this range. The results also show that micro organisms consume water during the growth and increasing the cell numbers. When the growth is high, therefore, the water content of the system reduces. The velocities of input moist air affect the biomass concentration. At the lower air velocity of 0.001 m/s results higher system temperature (325 ºK) which causes low fungal growth and high water evaporated.