Production of Extracellular Cold Active Lipase by Curtobacterium sp. using Cell Immobilization

A cold adapted lipolytic bacterium Curtobacterium sp. was isolated from the soil of Gangotri glaciers, Western Himalayas. The optimum temperature and pH for cold active lipase activity was 15 C and 8.0 respectively. The effect of different carbon sources, organic and inorganic nitrogen sources on production of cold active lipase were studied. Glucose served as a good source of carbon for the production of cold active lipase. Soyabean oil used as an additional carbon source induced the production of cold active lipase by two fold. Beef extract and ammonium nitrate was found to be a potential source of organic and inorganic nitrogen respectively. Curtobacterium cells immobilized in various concentrations of agar (1-4 %) and alginate (3-6 %) showed an enhanced production of cold active lipase of 9.00 U ml (in agar) and 6.00 U ml (in alginate) over the free cell fermentations. A decrease in total viable count of beads with increasing concentration of agar and alginate matrices were observed. However, the effect of dehydration on beads showed decrease in enzyme activity with increasing time duration. A consistent production of cold active lipase from cells immobilized in agar was observed in repeated batch culture.