Food Waste as a Feedstock for Fungal Biosynthesis of Amylases and Proteases

Purpose This work aimed the food waste (FW) valorization by the production of fungal enzymes in solid-state fermentation (SSF) and a hydrolysate with the potential to obtain products with high added value. Methods An original bioprocess based on Rhizopus oligosporus cultured by SSF using medium consisting of FW, sugarcane bagasse (SCB), wheat bran (WB), and corn steep liquor (CSL) utilizing a cell-substrate recycling system was implemented. Results The highest outcomes were achieved using FW as the main substrate and the strategy of one cell recycling round. The best condition for amylase production (260.9 U/g) was the blend FW 50%, SCB 10%, WB 40% supplemented with a salt solution. For the highest protease level (665.5 U/g) the same mixture was supplemented by 20% CSL. Hydrolysis of FW with the enzymatic extract from the best specified blend produced 47.10 g/L of reducing sugars. Conclusion This bioprocess showed to be cost-effective, technically not demanding, and could be scaled up successfully for commercial goals. Graphical Abstract