Isolation and screening of alkaline protease producing bacteria from soil
Abstract
The aim of present study was to isolate alkaline protease producing bacteria from soil samples collected from various habitats. The isolation was done by serial dilution method. All the isolates were screened for alkaline proteolytic activity on Casein peptone yeast extract agar (CPYA) media. Protease activity was visualized as distinct clear zone obtained on CPYA using trichloroacetic acid. A total of 7 from 31 bacteria were screened based on the zone of proteolysis. Enzyme production was carried out by inoculating seed culture to the casein peptone yeast broth under submerged fermentation and incubating for 48 hours at 37°C in shaking incubator. After incubation, the fermented broth was filtered and cell free culture filtrate was used as the crude enzyme for assay. Among the positive strains, AP1 and AP2 produced highest titres of alkaline proteases i.e., 13.94 U/ml and 8.61 U/ml, and were found to be gram-positive rod and cocci respectively. Wash performance test of crude enzyme was done to check efficiency of enzyme. Alkaline protease obtained from AP1 and AP2 were effective in removing blood stain from cloth.
