KARAKTERISASI DAN PEMURNIAN ENZIM ALKALIN PROTEASE YANG DI PRODUKSI DARI Bacillus cereus STRAIN LS2B

Abstract

Protease enzyme from Bacillus cereus LS2B was successively purified by four step processes including centrifugation, ammonium precipitation, membrane dialysis, and hitrap ion exchange with DEAE sepharose FF matrix. The best concentration of ammonium sulfate to purified enzyme was observed 80%. Hitrap ion exchange chromatography was performed with flow rate 1.5 ml min-1, and the number of enzyme in once running was 52,5 ml in the 35 tube. Specific activities at crude enzyme, ammonium sulfate precipitation, membrane dialysis and hitrap ion exchange was 0.4 U/mg, 0.5 U/ml, 1.8 U/mg and 7.2 U/mg, respectively. By using hitrap ion exchange purification of alkaline protease from Bacillus cereus LS2B was observed 16 fold from crude enzyme. Furthermore, the yield decreased from 100% in crude enzyme to 2% by using hitrap ion exchange purification. The purified enzyme was characterized using SDS-PAGE obtained three specific protein molecules with each weight was 34 kDa, 17 kDa and 13 kDa respectively. The maksimum activity of pure anzyme alkaline protease from Bacillus cereus LS2B obtained at 40o C and pH 8.