表面活性剂对华根霉脂肪酶有机相酯合成活性的激活

Activation of Esterification Activity of Rhizopus Chinensis Lipase in Organic Media by Surfactant

利用表面活性剂结合无机盐与华根霉(Rhizopus chinensis)脂肪酶(RCL)共冻干,以提高RCL在有机相中的酯合成活性.结果表明,n-十二烷基-β-D-麦芽糖苷(DDM)可以显著激活RCL的酯合成活性.DDM激活效果的关键影响因素是DDM与RCL的摩尔比,而非DDM浓度;当二者摩尔比大于30时,RCL酯合成活性随着该比值的增大而提高.此外,添加适量无机盐可以进一步强化DDM对脂肪酶酯合成活性的激活效果.利用激活的RCL分别在有机溶剂和无溶剂体系中催化生物香料己酸乙酯和生物柴油油酸乙酯的合成,酯合成效率得到明显提高,表明该方法的有效性和适用性.

Rhizopus chinensis lipase(RCL)was co-lyophilized with surfactants and/or inorganic salts to improve the esterification activity in organic solvent.Effects of type and concentration of surfactants and/or inorganic salts on esterification activity were investigated.The results demonstrate that n-dodecyl-β-D-maltoside(DDM)can enhance esterification activity of RCL effectively.The critical factor for activation of non-aqueous activity is molar ratio of DDM to RCL,rather than concentration of DDM.Esterification activity cannot be activated until the molar ratio is greater than 30,and then increase with the ratio.Furthermore,addition of appropriate inorganic salts in medium can strengthen the DDM-induced activation.The DDM-activated RCLs were used to catalyze the synthesis of ethyl hexanoate in organic media and ethyl oleate in solvent-free system.Higher reaction rate and conversion were obtained,which suggests the applicability of this method.