Production of Protease from Aspergillus flavus via Solid-State Fermentation Using Rice Husks as Substrate

Protease is one of the industrial enzymes which can be produced by microbes especially fungi. In the present study, Aspergillus flavus was used for the production of protease and could be obtained via optimization of solid state fermentation (SSF) parameters to get the optimum level of incubation period, initial moisture content, and temperature. Rice husk was used as a substrate to grow the A. flavus in SSF. Rice husk was used because their removal was said to create disposal problem because of their less commercial interest. Thus, utilization of rice husk as substrate under SSF can helps to reduce pollution. Additional investigation was firstly performed to determine the proteolytic activity of protease produced by A. flavus on skim milk agar plates and the result showed that only narrow zone was produced by the protease. Nevertheless, investigation on the protease activity produced by A. flavus was done after that. It was shown to be a good producer of protease in day 6 of incubation period with 0.100 U/ml of protease activity. Optimum initial moisture content was at 70% with 0.106 U/ml of protease activity and optimum temperature for the activity of protease produced by A. flavus was at 35°C with 0.238 U/ml