Temperature control at different bed depths in a novel solid-state fermentation system with two dynamic changes of air

A novel and effective bioreactor with two dynamic changes of air (including air pressure pulsation and internal air circulation) was developed and tested. It could enhance the heat transfer and effectively control the temperature variation in the process of solid-state fermentation (SSF) for cellulase production through changing the pressure range of air pulsation, air pulsation period and rate of internal air circulation and so on. After the optimization of the operating conditions, the maximum temperature gradient in the dynamic system with a bed height of 9.0 cm was 0.12 °C cm−1.