| Food waste has been reported as the potential bioresource for screening microorganisms producing protease since its composition is rich in protein and fat that are good as culture media for microorganisms including bacteria. This study was aimed to characterize crude protease produced by Aeromonas aquariorum isolated from tofu waste. Crude enzyme was produced in skim milk with minimum media liquid for 2 days to produce protease specific activity of 0.379 U/mg. Zymographic profile showed that enzyme had broad substrate specificity towards casein, gelatin, and fibrinogen. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the enzyme consisted of single band with molecular weight of 73 kDa. Enzyme had optimal pH at 12 and optimal temperatures at 37 and 70 °C. Enzyme was inihibited by a serine protease inhibitor, phenylmethylsulfonyl fluoride. The enzyme activity was not affected by ion cofactors. For its enzyme kinetic, the apparent Km and Vmax values of A. aquariorum crude enzyme toward casein were 4.069 mg/mL and 0.437 U/mg, respectively. Overall, crude protease from A. aquariorum had a potential catalytic performance, alkalophilic, thermostable, broad substrate specificity, and maximum catalytic efficiency at low substrate concentration. |