Isolation and characterization of extracellular protease producing bacteria

One hundred and twenty different bacteria were isolated from three selected sites of drain discharging Daphrin Hospital effluent into Sagar lake. All the isolates were purified and screened for the production of protease. On the basis of colony size, texture, microscopic characteristics and screening for protease enzyme, the isolates were categorized as proteolytic and non-proteolytic. Out of 29 protease producing isolates, ten were found good enzyme producers and 19 as poor. Three isolates, Planococcus sp. DH-2A, Planococcus sp. DH-5A and Micrococcus lylae DH-8C, which showed best enzymatic spectrum, had optimum enzyme activity in pH range of 7 – 8 and temperature of 40 − 50 °C. Metals like K₂HPO₄ and BaCl₂ reduced the enzyme production, whereas CaCl₂ and MgSO₄ increased. EDTA inhibited enzyme production much less in Micrococcus lylae when compared to Planococcus sp. (DH-2A) and Planococcus sp. (DH-5A) and therefore was not considered as serine protease.