正己烷反应体系中酶法转化乙酸3-甲硫基丙醇酯的工艺条件

Preparation of natural aroma ethyl-3-methyl-thiopropionate (EMTP) from biocatalysis reaction in normal hexane system

研究了脂肪酶催化合成天然香料乙酸3-甲硫基丙醇酯(EMTP)的关键因素及条件。以发酵3-甲硫基丙醇、乙酸为主要原料酶法合成EMTP的反应中,固定化Novozym435脂肪酶为最佳催化剂,正己烷作为溶剂有利于提高酶活力;在正己烷反应体系中,Novozym435用量、分子筛吸水剂用量、乙酸加入次数、反应温度、反应时间等因素对EMTP合成有重要的影响,添加Novozyme43550mg、分子筛2g、反应温度40℃、乙酸分3次加入、摇瓶速率100～150r/min,反应30h为较佳的反应条件,其EMTP产量为6.5mg/mL。

The production of natural aroma ethyl-3-methyl-thiopropionate （EMTP） by biocatalytic synthesis in non-aqueous system was studied. The results indicated that the best catalyst dosage was immobilized lipase Novozym435,and normal hexane as solvent was helpful to improve the activity of lipase in the reaction system. the amount of Novozym435,molecular sieve,the added times of acetic acid,reaction temperature,reaction time were important factors on the EMTP synthesis. And the optimal conditions in normal hexane medium were that lipase 50mg,molecular sieve 2g,reaction temperature 40℃ ,reaction time 30h,three times of acetic acid added,shaked speed 150r/min. The production rate of EMTP reached 6.5mg/mL under the optimized operation conditions.