摘要：A protease producing Bacillus licheniformis was isolated from abattoir soil sample. Selection of the isolate was based on the production of the highest zone diameter of 39 mm on skim milk agar. In a preliminary experiment, bacterial growth was measured as increase in optical density (OD) of medium at 600nm. There were increases in OD from 0.01 at 0 h to 0.66 after 48 h. Protease production also increased from the time of incubation at which 0.11 Units /mg protein were produced to 51.4 Units /mg protein after 48 h and decreased after 72 h. The best carbon and nitrogen sources for enzyme production were glucose and peptone respectively, while the most effective inorganic nitrogen source was observed to be ammonium chloride. Among the agricultural raw carbon sources used, cane sugar, corn flour, rice flour caused the production of 51.0, 43.2, 46.1 Units/ mg protein respectively after 48 h incubation. Agricultural raw nitrogen sources namely, soy bean meal and corn steep liquor caused the production of best enzyme activities of 50.8 and 42.4 Units/ mg protein respectively. Best enzyme activities were observed in media containing metal ions like Ca2+, Mg2+ and Mn2+. The organism produced protease in broad temperature range of 15-60 ºC and pH range of 4.0 to 11.0. The optimum conditions observed for protease production were 35 ºC and pH 9.0. The above results indicate that this isolated bacterium can be useful as a biotechnological tool for industrial purpose.
