Laboratory of Biochemistry and Enzymatic Engineering of Lipases, National School of Engineers of Sfax, University of Sfax, PB 1173, Km 4 Road Soukra, Sfax, Tunisia.
Laboratory of Biochemistry and Enzymatic Engineering of Lipases, National School of Engineers of Sfax, University of Sfax, PB 1173, Km 4 Road Soukra, Sfax, Tunisia.
Int J Biol Macromol. 2019 Feb 15;123:792-800. doi: 10.1016/j.ijbiomac.2018.11.050. Epub 2018 Nov 12.
A newly isolated Serratia sp. W3 strain was shown to secrete a non-induced lipase in the culture medium. Lipolytic activity was optimized using the response surface methodology (RSM) and the extracellular lipase from Serratia sp. W3 (SmL) was purified to homogeneity with a total yield of 10% and its molecular mass was estimated of about 67 kDa by SDS-PAGE. The amino acid sequence of the first 7 N-terminal residues of SmL revealed a high degree of homology with other Serratia lipase sequences. The purified SmL can be considered as thermoactive lipase, its maximal specific activity measured at pH 9 and 55 °C was shown to be 625 U/mg and 300 U/mg using tributyrin and olive oil emulsion as substrate, respectively. In contrast to other described Serratia lipases, SmL was found to be stable at a large scale of pH between pH 5 and pH 12. SmL was also able to hydrolyze its substrate in presence of various oxidizing agents as well as in presence of surfactants and some commercial detergents. Then, considering the overall biochemical properties of SmL, it can be considered as a potential candidate for industrial and biotechnological applications, such as synthesis of biodiesel and in the detergent industry.
一株新分离的沙雷氏菌 W3 菌株被证明能在培养基中分泌一种非诱导型脂肪酶。采用响应面法（RSM）对脂肪酶活力进行了优化，从沙雷氏菌 W3（SmL）中提取并纯化了细胞外脂肪酶，总产率为 10%，其相对分子质量约为 67kDa，通过 SDS-PAGE 测定。SmL 的 N 端 7 个氨基酸序列与其他沙雷氏菌脂肪酶序列具有高度同源性。纯化的 SmL 可视为热活性脂肪酶，其在 pH9 和 55°C 时的最大比活性分别为 625U/mg 和 300U/mg，分别使用三丁酸甘油酯和橄榄油乳液作为底物。与其他描述的沙雷氏菌脂肪酶不同，SmL 在 pH5 到 pH12 的较大 pH 范围内稳定。SmL 还能够在各种氧化剂、表面活性剂和一些商业洗涤剂存在的情况下水解其底物。考虑到 SmL 的整体生化特性，它可以被认为是工业和生物技术应用的潜在候选者，如生物柴油的合成和洗涤剂行业。
