Effect of several factors on soluble lipase-mediated biodiesel preparation in the biphasic aqueous-oil systems
Effect of several factors on soluble lipase-mediated biodiesel preparation in the biphasic aqueous-oil systems
复制标题
双相水油体系中多种因素对可溶性脂肪酶介导的生物柴油制备的影响
DOI：
10.1007/s11274-008-9714-6
复制
发表时间：
2008-10-01
影响因子：
4.1
通讯作者：
Liu, Dehua
中科院分区：
文献类型：
--
作者：
Chen, Xin;Du, Wei;Liu, Dehua
生物柴油日益被视为解决当前化石燃料短缺和环境污染等重要问题的重要组成部分。利用可溶性脂肪酶为固定化酶或全细胞催化脂肪酶催化生物柴油的生产提供了一种替代方法。可溶性脂肪酶NS81020是由转基因米曲霉微生物深层发酵产生的，首次被提出作为油酸在水-油双相体系中制备生物柴油的催化剂。系统考察了酶浓度、水含量、温度、甲醇油摩尔比、搅拌速率和缓冲液pH等因素对酯化率的影响。在双相水-油体系中，在不达到酶在界面上的最大吸附量的情况下，随着酶浓度的增加，反应时间可以缩短。双相水-油体系的最佳含水量为油酸重量的10%。随着甲醇与油摩尔比的增大、搅拌速率的增大和温度的降低，反应速率加快。虽然可溶性脂肪酶NS81020在pH为10.55时活性较低，但羟基离子抑制了甲酯的水解，促进了甲酯的生成。
Biodiesel is increasingly perceived as an important component of solutions to the important current issues of fossil fuel shortages and environmental pollution. Utilization of soluble lipase offers an alternative approach to lipase-catalyzed biodiesel production using immobilized enzyme or whole-cell catalysis. Soluble lipase NS81020, produced by submerged fermentation of genetically modifiedAspergillus oryzaemicroorganism, was first proposed here as the catalyst of biodiesel preparation with oleic acid in the biphasic aqueous-oil systems. The effect factors such as enzyme concentration, water content, temperature, molar ratio of methanol to oil, stirring rate and pH of buffer solution on the esterification rate were investigated systematically. The reaction time could be shortened with the increasing of enzyme concentration as long as the maximum enzyme absorptive capacity on the interface in the biphasic aqueous-oil systems was not achieved. The optimal water content in the biphasic aqueous-oil systems was 10 wt% by oleic acid weight. The reaction rate was enhanced with the increasing molar ratio of methanol to oil, the increasing stirring rate or the decreasing temperature. Although soluble lipase NS81020 had lower activity at pH 10.55, hydroxyl ion conduced to restrain hydrolysis of methyl ester and facilitated the reaction toward the methyl ester formation.