Partial purification and characterization of protease enzyme from soil borne bacteria

Abstract

Protease enzyme from bacterial isolates AKS-4 and AKS-6 was successfullypurified by ammonium sulfate precipitation. Purified enzyme fractionate obtained from 80% salt saturation showed highest protease activity. Proteaseactivity of crude lysate was increased after purification with 80% salt concentration. Purified protease fractions (80% salt saturation) obtained from bacterial isolate-AKS-4 and AKS-6 were named as P-1 and P-2, respectively with protease activity of 35.07 U/mL and 34.46 U/mL. Extracellular protease from isolate AKS-4 was purified to 9.29 fold by (NH4)2SO4. Enzyme fractionates P-1 and P-2 showed increased activity at neutral and alkaline pH range while enzyme activity was reduced under acidic pH. P-1 and P-2 demonstrated increased protease activity at higher temperature range (50 \ ºC, 60 ºC). The impact of different divalent metal ions and organic solvents on protease activity of both enzyme fractions was investigated. Highest protease activity by both enzyme fractions was obtained with calcium chloride and n-butanol.