The production of protease by the thermophilic Bacillus sp. SMIA-2 cultivated in a medium containing whey and corn steep liquor was studied. In addition, the compatibility of the enzyme with commercial detergents was evaluated. The maximum activity of the enzyme (70 U/mg protein) was observed in the phase stationary of growth, with 32 h of incubation. Studies on the protease characterization revealed that the optimum temperature of this enzyme was 70 °C and that it maintained 91% of its activity when incubated a 70 °C in the presence of calcium. The optimum pH of the enzyme was found to be 8.0 and the enzyme maintained 85% and 46% of its original activity when incubated for 1 h at pH 9 and pH 10 respectively. Protease retained 64% and 50% of its activity after 30 min incubation at 70 °C in presence of the detergents Cheer® and Tide® respectively. The addition of glycine and calcium improved the stability of the enzyme in all detergents used. In the presence of the detergents Ultra bizz®, Cheer® and Tide®, the enzyme maintained 100% of its activity after 30 min of incubation at 70 °C.
proteases; milk whey; commercial detergents; Bacillus sp
