Optimizing Protease Production using Solid State Fermentation: Wheat Bran as an Ideal Substrate and its Application in the Food Industry

This study investigates the production of alkaline proteases using a method known solid state fermentation (SFF) with Aspergillus oryzae strain. The aim was to determine the best conditions for achieving high enzyme activity. Initially, nine different local agricultural material were tested: Wheat bran dried leaves, sugar cane bagasse, rice polish, wheat straw, peanut shells, corn straw, lemongrass, and rice straw. Among these, wheat bran was found to be the most effective substrate for producing proteases. Its high fiber and cellulose content promote good fungal growth and enzyme secretion. The researchers employed a method known as Response Surface Methodology (RSM) to increase the output of enzymes. The pH levels (between 2 and 9.5), temperature (between 30°C and 52°C), incubation period (between 1 and 10 days), inoculum volume (1 to 8 ml), humidity (20 to 125%), and substrate quantity (1 to 7 g) were among the critical conditions that were optimized by this method. The ideal parameters were determined using RSM to be pH 8, 30°C, 8 days of incubation, 5 mL of inoculum, 60% humidity, and 4 g of substrate. A high enzyme activity measurement of 909.698 U/ml at 660 nm was obtained using these parameters. Following production, the protease was purified using techniques such as dialysis with ammonium sulfate precipitation, and gel filtering. After that, it was evaluated the proteases one variable at a time, ensuring that they were appropriate for a range of industrial uses. In the food business, the proteases were very effective since they increased dough's volume and texture, which enhanced the quality of baked goods. In order to more clearly see and understand how various environments impact enzyme synthesis, the study also included the creation of 3D charts and graphs utilizing programs like Minitab 17 and Excel 2013. In the end, this approach showed that Aspergillus oryzae and wheat bran were a successful way to produce alkaline proteases. The results point to the potential industrial use of these enzymes, particularly in the food industry, and call for additional investigations into alternative agricultural components for enzyme synthesis.