摘要
以硅藻土和纺织品为载体 ,采用吸附法制备固定化脂肪酶 ,研究了固定化假丝酵母 99 1 2 5脂肪酶在有机溶剂中催化脂肪酸低碳醇酯酯化合成过程中 ,有机溶剂性质、脂肪酸与低碳醇的结构、pH值、反应温度和体系含水量、低碳醇的抑制作用等因素对酯化过程的影响。试验结果表明 :底物低碳醇需要采用流加方式加入体系 ,石油醚是最适宜的有机溶剂 ,脂肪酸与醇的碳链越长 ,越易于酯化 ;固定化脂肪酶对直链醇的选择性优于支链醇。以石油醚为有机溶剂 ,在反应温度为 40℃、pH值为 7时 ,硬脂酸与甲醇的酯化率达 95 % ;反应后期应除去体系中的水以避免酶失活。固定化酶间歇催化油酸与甲醇的酯化时 ,重复使用 1 5次 (每次 2 4h) ,其操作半衰期约为 360h。
Immobilized lipase from Candida sp. 99 125 was prepared by using diatomite or textile as supporter.Effects of various factors on esterification of fatty acids and short chain alcohol in solvent were studied,including properties of solvent,structure and the chain length of fatty acids and alcohol,pH,temperature,amount of water and enzyme,inhibition of short chain alcohol on enzymatic reaction.Results show that: short chain alcohol must be added by fed batch,and the best solvent is petroleum ether; the longer carbon chain of fatty acid and alcohol is,the easier esterification can be; selectivity of lipase from straight chain alcohol is better than from branch chain alcohol.95% of esterification yield can be achieved at 40℃ under pH=7.Riddance of water from the system should be done at the approaching end of reaction to prevent lipase from losing its activity.The immobilization lipase can be reused by 15 times (each time for 4 h),and half life of immobilized lipase for esterification process can be about 360 h.
出处
《现代化工》
EI
CAS
CSCD
北大核心
2002年第9期30-33,37,共5页
Modern Chemical Industry
基金
国家自然科学基金资助项目 (2 0 1 760 0 2 )
