Fermentative production of an alkaline extracellular lipase using an isolated bacterial strain of Serratia sp (C4)

Twenty organisms were isolated from spoiled coconut using olive oil medium. Only seven of the isolated strains were found capable of producing lipase. The isolate C4 was shown the maximum enzyme activity of 9.4I.U/ml. the isolated microbial strain was identified as Serratia sp after the determination of the morphological and biochemical characteristics. The maximum lipase production was achieved at 300C, pH 8.0 on 72 hours of fermentation. Optimum volume of the medium, age of the inoculum and volume of the inoculum were 50ml, 24hr and 2 %( v/v) respectively. Superior carbon and nitrogen sources for lipase production were starch (2%); ammonium chloride (0.38%) and peptone (2%) in combination respectively. The optimum C/N ratio was found to be 0.076:1. Ammonium sulphate of 40% concentration level was found to be superior precipitating agent during the isolation and purification of extracellular alkaline lipase. The maximum specific activity of the purified lipase was found to be 16.16I.U/mg and purification fold of 7.3. Key words: Lipase, extracellular, isolation, Enzyme activity, process optimization