Isolation and screening of protease producing bacteria from different market soils

Abstract

The objective of the present study was to isolate and screen protease producing bacteria from soil samples collected from local markets. Total sixteen bacterial colonies were isolated and streaked on gelatin agar plate and incubated at 37ºC for 48 hours, after which four isolates showed clear zone around the colony indicating protease activity. This was followed by morphological, biochemical test and MALDI-TOF-MS. Among the four isolates (T1, T2, T3, T4) T4 isolate produced highest protease activity, identified as Bacillus subtilis. The optimization parameters like pH, temperature and incubation time was observed and noted a maximum activity of 47.1 U/ml at pH 7 and the temperature for maximum activity (16.59 U/ml) of enzyme was found to be 40ºC in 24 hours. The unknown concentration of crude protease was determined using tyrosine standard curve. These parameters were carried out for rest of the 3 isolates and values recorded which showed similar trend as that of T4 isolate. Hence, a novel source for the production of protease from soil samples obtained from different market sources was approached at the end of this study