Isolation and characterization of Staphylococcus hominis JX961712 from oil contaminated soil

Abstract

BackgroundOnly about 2% of the world's microorganisms have been tested as enzyme sources. Enormous biodiversity of organisms improves alternative biotechnological processes justifies the search for new lipases. Enzymes are considered as nature's catalysts. Lipids constitute a large part of the earth's biomass and lipolytic enzymes play an important role in the turnover of these water insoluble compounds. Most enzymes today are produced by fermentation. The benefits offered by enzymes are specificity, mild conditions and reduced waste. It may be possible, by choosing the right enzyme, to control the product production and also unwanted side reactions are minimized due to specificity of enzymes. ObjectivesTo screen, isolate and identify lipase producing organism from oil contaminated soil sample at Salem District, Tamil Nadu, India, in order to optimize the growth conditions and to assess the activity of lipase as an attempt to produce wealth from waste. MethodologyMorphological, Biochemical characterization of the isolate was evaluated and final confirmation was done by 16S rRNA gene sequencing. Optimization of different parameters were carried out to find the lipase activity. Results16S rRNA gene sequencing confirms the organism as Staphylococcus hominis MTCC 8980 and the strain was named as MK-1. The sequence was submitted in GenBank under the accession number JX961712. The G + C content was found to be 51.5%.Maximum lipase production was found to be 17.8 U/ml at 48hr incubation period and 14.7 U/ml at pH7 and at 40 °C it was found to be 22.3 U/ml. Among the oil sources selected, olive oil was found to be a best lipase producer, as it produces 13.5 U/ml. Among the organic nitrogen sources selected yeast extract showed 19.5 U/ml, 22 U/ml in Triton X100 and 14.6 U/ml in Hexane.Ca2+induces lipase activity up to 21.5 U/ml whereas Hg2+, Ni2+ inhibits lipase activity. ConclusionS. hominis was effective in producing lipase in moderate amount with the provided nutritional factors in the lipase production medium.