Characterization of Lipase from Bacillus subtilis I-4 and Its Potential Use in Oil Contaminated Wastewater

ABSTRACT

A lipase producing bacterium was isolated from oil contaminated effluents of various industries from Sheikhupura Road, Pakistan, and, on the basis of biochemical and 16S rRNA ribotyping, was identified as Bacillus subtilis. The optimum temperature and pH for the growth of the culture were 37ºC and 7.0, respectively. B. subtilis I-4 had a lag phase of 4 h in LB medium while this phase prolonged to 6 h in oil containing medium. The optimum temperature and pH for the enzyme activity were 50ºC and 7.0, respectively. Maximum lipase activity was found in the presence of Ca ions. Olive oil and Tween 80 induced lipase gene in the bacterium while concentration of oil greater than 2% retarded the growth of the organism. In addition to lipase B. subtilis I-4 also produced alkane hydroxylase and biosurfactant which could make this bacterium potential candidate for lipase production as well as bioremediation of oil-contaminated wastewater.

Key words:
Bacillus subtilis I-4; lipase; alkane hydroxylase