Full Length Research Paper

Isolation and characterization of lipase-producing Bacillus strains from oil mill waste

T. Selva Mohan¹*, A. Palavesam² and G. Immanuel²

¹P. G. Department of Microbiology Sivanthi Aditinar College, Nagercoil-629501. K.K. Dist. South India.

²Center for Marine science  and Technology, Manonmaniam Sundarnar University, Rajakkamangalam –629502. K.K. Dist. South India.

*Corresponding author. E-mail: jgmohan71@yahoo.co.in.

Accepted 10 June, 2008

Bacillus strains (B1 - B5) producing extra cellular lipase were isolated from the soil sample of coconut oil industry. The strains were identified by morphological and biochemical characters. Growth of the organisms and lipase production were measured with varying pH (4 - 9) temperature (27, 37 and 47ºC) and various substrate concentrations. The result indicated that the lipase production varied between Bacillus strains and also between varying parameters tested. The maximum lipase production was recorded at pH 7 during 24 h of the culture period by Bacillus strain B5. Among the substrates tested, coconut oil at a concentration of 0.5% was found to enhance the lipase production in the same Bacillus strain B5. Further the effect of medium temperature indicated that the production of lipase was maximum at 37ºC. Statistical analysis revealed that the variation in lipase production was highly significant between bacterial strains than the independent influence of pH, substrates concentration and medium temperature.

Key words: Bacillus, lipase, substrates.