Sivaramakrishnan Ramachandran, Incharoensakdi Aran
Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
J Biosci Bioeng. 2016 May;121(5):517-22. doi: 10.1016/j.jbiosc.2015.09.005. Epub 2015 Oct 20.
Lipase from Bacillus sp. isolated from the oil contaminated soil was purified by ammonium sulphate precipitation and ion-exchange chromatography with a 5.1-fold purification and 10.5% yield. SDS-PAGE analysis of the enzyme revealed the molecular mass of 24 kDa. The optimum pH and temperature for lipase activity were 6.5 and 37°C, respectively. The isolated lipase was stimulated by pretreatment with methanol and ethanol as well as by divalent metal ions Ca(2+), Mg(2+) and Mn(2+). The enzyme showed high activity towards oleic rich oils. The enzyme immobilized on celite could retain 90% lipase activity after eight cycles. Transesterification of Botryococcus sp. oil using the immobilized enzyme for 40 h resulted in 80% yield of fatty acid methyl esters which had good properties for use as biodiesel. Overall results suggested that the solvent tolerant Bacillus lipase can be a potential biocatalyst for methyl ester production.
从受油污染土壤中分离出的芽孢杆菌属脂肪酶，通过硫酸铵沉淀和离子交换色谱法进行纯化，纯化倍数为5.1倍，产率为10.5%。对该酶进行的SDS-PAGE分析显示其分子量为24 kDa。脂肪酶活性的最适pH值和温度分别为6.5和37°C。分离出的脂肪酶受到甲醇和乙醇预处理以及二价金属离子Ca(2+)、Mg(2+)和Mn(2+)的刺激。该酶对富含油酸的油表现出高活性。固定在硅藻土上的酶在八个循环后可保留90%的脂肪酶活性。使用固定化酶对葡萄藻属油进行40小时的酯交换反应，脂肪酸甲酯的产率为80%，其具有用作生物柴油的良好性能。总体结果表明，耐溶剂芽孢杆菌脂肪酶可能是甲酯生产的潜在生物催化剂。
