A NOVEL ORGANIC SOLVENT STABLE SERINE PROTEASE FROM A NEWLY ISOLATED

摘要

During our screening for novel proteases, a Serratia sp. Was isolated from alkaline soilsthe Himalayas, a biodiversity rich hotspot and identified according to polyphasic approachwhich includes morphological, biochemical and physiological characteristics and 16S rDNAsequence analysis. The protease was purified to homogeneity by acetone precipitationfollowed by gel filtration using Sephacryl S-100. The intact molecular mass of purified proteasewas determined by MALDI TOF and SDS-PAGE. The enzyme was highly active in the pHrange of 6.0 to 11.0 and the optimum pH and temperature were found to be 7.5 and 50°C,respectively. The protease was characterized as serine protease based on the studies onclass specific inhibitors and retained 92 % and 99 % of its activity in the presence of sodiumperborate (0.5 %, w/v) and dodecyl benzene sulphonate (0.1 %, w/v), respectively. Highstability in presence of detergents such as sodium dodecyl sulphate (0.1 %, w/v), Tween 80(1.0 %, w/v), Triton X-100 (1.0 %, w/v) and organic solvents such as dimethyl sulfoxide, ethylacetate and hexane (25 % and 50 % v/v) and its performance in stain removal makes thisSerratia protease as an ideal choice for industrial applications such as in detergent, leather,food, pharmaceutical and chemical synthesis industries.