Isolation And Characterization Of Proteases From Soil Microorganisms

ABSTRACT

Thirty-five strains capable of secreting extracellular proteases were isolated from canteen drainage, hostel drainage, refuse dump, orchard and garden soil in Michael Okpara University of Agriculture, Umudike Abia State. A plate assay based on the visible solubilization and formation of green colouration on Petri dishes containing a diversity of protein sources was used. This method was successfully applied for isolating the diverse protein degrading bacteria from different soils. Selected strains were identified using classical microbiological and biochemical characteristics. Five strains with the highest yield of proteases were identified as Bacillus spp. The cultural conditions were optimized for maximum enzyme production. Skimmed milk and Soybean were the best nitrogen source for protease production. Addition of 0.1 g peptone optimi7ed the production of the enzyme. Highly hydrolytic strains were isolated from canteen, refuse dump and hostel drainage soil sample, suggesting the existence of a microbial community well adapted to nutrient recycling in these environments.