ORIGINAL ARTICLE Lipase production by Staphylococcus epidermidis CMST-Pi 1 isolated from the gut of shrimp Penaeus indicus Palanichamy Esakkiraj & Mariappan Rajkumarbharathi & Arunachalam Palavesam & Grasian Immanuel Received: 23 April 2009 / Accepted: 16 November 2009 / Published online: 5 January 2010 # Springer-Verlag and the University of Milan 2009 Abstract A bacterium producing extracellular lipase was isolated from the gut of the estuarine shrimp Penaeus indicus and identified as Staphylococcus epidermidis. Lipase production was investigated in shake-flask culture. Cod liver oil was found to be a suitable triglyceride to increase lipase production, at an optimum concentration of 1.5%. Investigating the effect of carbon source on lipase production revealed that fructose yielded higher lipase production than the other tested carbon sources; the optimal concentration of fructose was 2.5%. Screening of a suitable nitrogen source for lipase production revealed that meat extract yielded higher lipase production; the optimal concentration of meat extract for higher lipase production was 2.0%. The most suitable trace element for maximum lipase production was zinc sulphate, followed by magnesium sulphate. Partial characterization of the crude lipase revealed that pH 7 and a temperature of 50°C gave optimal lipase activity. Testing the effect of various organic solvents on lipase activity revealed that hexadecane (77%), tetradecane (74%) and dodecane (48%) increased lipase activity over the control. Keywords Staphylococcus epidermidis . Lipase . Shrimp gut bacterium . Hexadecane . Cod liver oil Introduction Lipases (EC 3.1.1.3) are defined as carboxylesterases that catalyze both hydrolysis and synthesis of long-chain acylglycerols. They are produced by several microorgan- isms, namely bacteria, fungi, archea and eucarya, as well as by animals and plants. In particular, lipases from fungi are important in industrial applications (Essamri et al. 1998). Compared to plant and fungal lipases, bacterial lipases have been well studied. Among lipase-producing microbes, Candida sp., Pseudomonas sp., Bacillus sp., Acinetobacter sp., Staphylococcus sp., Rhizopus sp. and Aspergillus sp. are the important sources (Pandey et al. 1999). Lipases have many industrial applications including in organic chemical processing, detergent formulations, syn- thesis of biosurfactants, the oleochemical industry, the dairy industry, the agrochemical industry, paper manufacture, nutrition, cosmetics, and pharmaceutical processing. The main commercial application of lipases is their use in laundry detergents; detergent enzymes make up nearly 32% of the total lipase sales (Liese et al. 2000). Nowadays, organic-solvent-tolerant enzymes, especially lipase, have come into focus because of their ability to markedly improve the production of biodiesel. It was found that some lipases, especially those from the genera of Pseudomonas and Bacillus, have the ability to tolerate methanol and ethanol, and hence could be used for the production of biodiesel from low cost precursors and waste lipids (Fang et al. 2006). In view of the above, the present study was undertaken to optimize culture conditions for lipase production by shrimp intestinal isolate Staphylococcus epidermidis CMST-Pi 1, which produces an organic-solvent- tolerant lipase. P. Esakkiraj : M. Rajkumarbharathi : A. Palavesam (*) : G. Immanuel Centre for Marine Science and Technology, Manonmaniam Sundaranar University, Rajakkamangalam 629 502, Kanyakumari District, Tamilnadu, India e-mail: plavesh06@gmail.com Ann Microbiol (2010) 60:37–42 DOI 10.1007/s13213-009-0003-x