Purification and biochemical characterization of a halotolerant Staphylococcus sp. extracellular lipase

详细信息    查看全文

• 作者：Lobna Daoud¹ ; Jannet Kamoun¹ ; Madiha Bou Ali ; Raida Jallouli ; Rim Bradai ; Tahar Mechichi ; Youssef Gargouri ; Yassine Ben Ali ; Ahmed Aloulou ; ^{aloulou@u.washington.edu}
• 关键词：TC4 ; tributyrin ; SDS-PAGE ; sodium dodecyl sulfate polyacrylamide gel electrophoresis ; OD ; optical density ; GA ; gum arabic ; rDNA ; ribosomal DNA
• 刊名：International Journal of Biological Macromolecules
• 出版年：2013
• 出版时间：June, 2013
• 年：2013
• 卷：57
• 期：Complete
• 页码：232-237
• 全文大小：597 K

文摘

We have isolated a lipolytic halotolerant bacterium, designated as CJ3, that was identified as a Staphylococcus sp. Culture conditions were optimized and the highest extracellular lipase production amounting to 5 U/ml was achieved after 24 h of cultivation. The extracellular lipase was puri?ed 24-fold by ammonium sulfate precipitation and a Sephacryl S-200 chromatography, and its molecular mass was found to be around 38 kDa, as revealed by SDS-PAGE and gel filtration. The lipase substrate specificity was investigated using short (tributyrin) and long (olive oil) chain triglyceride substrates. The lipase was inhibited by submicellar concentrations of Triton X-100, and maximum specific activities were found to be 802 U/mg on tributyrin and 260 U/mg on olive oil at pH 8.0 and 45 ¡ãC. The lipase was fairly stable in the pH range from 6.0 to 9.0, and about 69 % of its activity was retained after incubation at 45 ¡ãC for 60 min. The enzyme showed a high tolerance to a wide range of salt concentration and a good stability in organic solvents, especially in long-chain alcohols.