Influence of cultural conditions for extracellular lipase production by a Halotolerant Bacterium, Bacillus Sp. Ors4

Abstract

During the course of survey of halotolerant bacteria from saline environments, 17 bacterial cultures were isolated in pure form from the multi-pond solar salterns of Odisha and West Bengal, India. The isolates were screened for their lipase production capability on basal MH-Tween 80 agar medium containing 10% NaCl and the isolate ORS4 having potential for high lipase production, the most potent lipolytic isolate ORS4 was selected for further detailed studies. The ORS4 isolate showed most similarity to Bacillus vallismortis from genus Bacillus on behalf of the morphological, physiological and biochemical characteristics along with 16S rRNA gene sequence analysis. Time course of growth and lipase production by the isolate ORS4 showed maximum enzyme activity (35.79 U/ml) during the stationary phase of growth. Moreover, the optimum conditions for lipase production by the isolate in basal MH medium involved 1% Tween 80, 5% NaCl, 1% glucose, 1% tryptone with an inoculum density of 1012 cells/ml. The partially purified extracellular lipase of Bacillus sp. ORS4 showed tolerance to alkaline pH along with high salinity and temperature suggesting its potential for biotechnological applications in saline environments.