Department of Molecular Biology, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Denmark.
Biotechnol Lett. 2011 Oct;33(10):2065-71. doi: 10.1007/s10529-011-0671-z. Epub 2011 Jun 22.
Candida rugosa lipase (CRL) and Candida antarctica lipase A (CALA) with improved activity and selectivity were prepared for use in organic solvent media. CRL bioimprinted with fatty acids exhibited eightfold enhanced transesterification activity in hexane. Combination of bioimprinting and coating with lecithin or with immobilization did not improve the activity further. CALA was immobilized with and without bioimprinting, none of which improved the activity. All modified lipases were tested for selective ethanolysis of fish oil to concentrate omega-3 polyunsaturated fatty acids (PUFA). None of the preparations, except the immobilized ones catalysed ethanolysis. Immobilized CRL-catalyzed ethanolysis giving 27% (v/v) ethyl esters (EE) in 48 h, of which 43 mol% was oleic acid but no PUFA was detected in the EE fraction. Fatty acid selectivity of CALA was significantly improved by immobilization combined with bioimprinting, resulting in 5.5-fold lower omega-3 PUFA in EE.
为了在有机溶剂介质中使用，制备了具有改进的活性和选择性的皱褶假丝酵母脂肪酶（CRL）和南极假丝酵母脂肪酶 A（CALA）。用脂肪酸进行生物印迹的 CRL 在己烷中的酯交换活性提高了 8 倍。生物印迹与卵磷脂包被或固定化的组合并没有进一步提高活性。CALA 进行了生物印迹和非生物印迹的固定化，都没有提高活性。所有改性的脂肪酶都用于测试鱼油的选择性乙醇解，以浓缩 ω-3 多不饱和脂肪酸（PUFA）。除固定化酶外，没有任何一种制剂能够催化乙醇解。固定化的 CRL 催化乙醇解在 48 小时内得到 27%（v/v）的乙酯（EE），其中 43mol%为油酸，但 EE 部分没有检测到任何 PUFA。CALA 的脂肪酸选择性通过与生物印迹相结合的固定化得到了显著改善，导致 EE 中 ω-3 PUFA 的含量降低了 5.5 倍。
