Ben Salah Riadh, Ghamghui Hanen, Miled Nabil, Mejdoub Hafedh, Gargouri Youssef
Laboratoire de Biochimie et de Génie enzymatique des lipases, Ecole Nationale des Ingénieurs de Sfax, Route de Soukra, Boite Postale W, 3038 Sfax, Tunisia.
J Biosci Bioeng. 2007 Apr;103(4):368-72. doi: 10.1263/jbb.103.368.
A new lipase preparation from Rhizopus oryzae was used to catalyze the esterification reaction between acetic acid and butanol to produce butyl acetate ester (pineapple flavor). This flavor compound can be used in food, cosmetic and pharmaceutical industries. Only 3% of butyl acetate was obtained when free lipase was used in the synthesis containing only the substrates. In contrast, the conversion yield reached 25% when immobilized lipase was used under the same conditions. The synthesis of butyl acetate catalyzed by immobilized lipase in nonconventional media was optimized. A maximum conversion yield of 60% in a solvent-free system was obtained under the following conditions: amount of immobilized lipase, 500 IU; amount of initially added water, 45%; acetic acid/butanol molar ratio, 1:1; and in incubation temperature, 37 degrees C. Immobilized lipase could be repeatedly used for three cycles without a decrease in synthesis activity. The production of butyl acetate esters by immobilized R. oryzae lipase was also studied in the presence of organic solvents. Compared with a solvent-free system, the synthesis activity was improved in the presence of heptane and hexane with conversion yields of 80% and 76%, respectively. However, solvent-free systems tend to purify more easily the products without any toxicity and inflammability problems.
一种来自米根霉的新型脂肪酶制剂被用于催化乙酸和丁醇之间的酯化反应，以生产乙酸丁酯（菠萝味香料）。这种香料化合物可用于食品、化妆品和制药行业。在仅含有底物的合成反应中使用游离脂肪酶时，仅获得了3%的乙酸丁酯。相比之下，在相同条件下使用固定化脂肪酶时，转化率达到了25%。对固定化脂肪酶在非传统介质中催化合成乙酸丁酯的反应进行了优化。在以下条件下，在无溶剂体系中获得了60%的最大转化率：固定化脂肪酶用量为500 IU；初始加水量为45%；乙酸/丁醇摩尔比为1:1；孵育温度为37℃。固定化脂肪酶可以重复使用三个循环，且合成活性不会降低。还研究了在有机溶剂存在下固定化米根霉脂肪酶生产乙酸丁酯的情况。与无溶剂体系相比，在庚烷和己烷存在下合成活性得到了提高，转化率分别为80%和76%。然而，无溶剂体系往往更容易纯化产物，且不存在任何毒性和易燃性问题。
