Optimization of Protease Production Using Agro Wastes by Aspergillus spp. In A Solid-State Fermentation

Abstract

gricultural wastes are highly nutritious and facilitate microbial growth and metabolism. Most agro-wastes are lignocellulosic in nature, composed of lignin, hemicellulose and cellulose. Agricultural residues can be used for the production of various value-added products, such as industrially important enzymes. Extracellular proteases have high commercial value and multiple applications in detergents, food, dairy, pharmaceutical, leather, diagnostics, waste management and several recovery industries. Aspergillus oryzae was isolated from rice farmland, Rigasa, Kaduna. It was screened for protease production using skimmed milk agar assay with a wider clear zone of casein hydrolysis (halo zone). The main objectives of this study were to isolate, characterized, and optimize the production conditions by Aspergillus oryzae under solid state fermentation (SSF) using locally available agricultural wastes used as substrate. The results showed that the optimum conditions for maximum protease production are 84 hours of incubation; pH 6.0; temperature of 35ᵒC; 3% inoculum size; peptone as Nitrogen source and rice husk as the best fermentation substrate. The highest protease activity of rice husk was 1350 Ug−1 of dry solids compared with an activity of corn cob 1005 Ug−1 respectively. Protease was produced from Aspergillus oryzae with broad substrate specificity, high pH and temperature stability.