Abstract

Biodetergents are preferred over the conventional synthetic detergents in view of their better cleaning properties, low energy input and the alleviation of pollution. The biodetergents derived from mesophilic/thermophilic organisms and also peroxide-based synthetic detergents require high temperature for their optimum activity. Thus, cold-active enzymes are very useful as they work at lower temperatures and do not require the input of energy. The purpose of the present study was the production optimization and purification of cold-active alkaline protease from a novel psychro-tolerantStenotrophomonas maltophilia MTCC 7528 and its application as a detergents additive for cold washing. Psychro-tolerant proteolytic bacterium S. maltophilia MTCC 7528 was isolated from soil of Gangotri glacier, Western Himalaya, India that produced maximum protease (56.2 U/ml) at 20°C and pH 9.0 after 120 h incubation in shaking condition (120 rev/min). The purified enzyme has molecular weight of 75 kDa with maximum activity and stability at pH 10 and 20°C temperature. It showed excellent compatibility with commercial detergents with improved cleansing power at low temperature. The enzyme completely removed blood and grass stains and increases the reflectance by 26 and 23%, respectively. Enzyme-based detergents find a wide range of applications in laundry and textile industries. Cold-active alkaline protease from psychro-tolerant S. maltophilia may be a potential component to be used as a detergent additive for cold washing that will be beneficial to save energy as they work at lower temperatures.

Key words: Alkaline protease, biodetergent, cold-active enzymes, wash performance.