Faculty of Industrial Chemistry and Environmental, University "Politehnica" of Timisoara, C. Telbisz 6, 300001 Timisoara, Romania.
Molecules. 2012 Nov 2;17(11):13045-61. doi: 10.3390/molecules171113045.
Sol-gel entrapment is an efficient immobilization technique that allows preparation of robust and highly stable biocatalysts. Lipase from Candida antarctica B was immobilized by sol-gel entrapment and by sol-gel entrapment combined with adsorption on Celite 545, using a ternary silane precursor system. After optimization of the immobilization protocol, the best enzyme loading was 17.4 mg/g support for sol-gel entrapped lipase and 10.7 mg/g support for samples obtained by entrapment and adsorption. Sol-gel immobilized enzymes showed excellent values of enantiomeric ratio E and activity when ionic liquid 1-octyl-3-methyl-imidazolium tetrafluoroborate was used as additive. Immobilization increased the stability of the obtained biocatalysts in several organic solvents. Excellent operational stability was obtained for the immobilized lipase, maintaining unaltered catalytic activity and enantioselectivity during 15 reuse cycles. The biocatalysts were characterized using scanning electron microscopy (SEM) and fluorescence microscopy. The improved catalytic efficiency of entrapped lipases recommends their application for large-scale kinetic resolution of optically active secondary alcohols.
溶胶-凝胶包埋法是一种有效的固定化技术，可用于制备坚固且高度稳定的生物催化剂。通过溶胶-凝胶包埋和溶胶-凝胶包埋与 Celite 545 上吸附相结合，使用三元硅烷前体系统对南极假丝酵母 B 的脂肪酶进行了固定化。在优化固定化方案后，对于溶胶-凝胶包埋脂肪酶，最佳的酶负载量为 17.4 mg/g 载体，对于通过包埋和吸附获得的样品，最佳的酶负载量为 10.7 mg/g 载体。当使用离子液体 1-辛基-3-甲基-咪唑四氟硼酸盐作为添加剂时，溶胶-凝胶固定化酶具有出色的对映体比率 E 和活性值。固定化提高了所得生物催化剂在几种有机溶剂中的稳定性。固定化脂肪酶具有出色的操作稳定性，在 15 次重复使用循环中保持催化活性和对映选择性不变。使用扫描电子显微镜 (SEM) 和荧光显微镜对生物催化剂进行了表征。包埋脂肪酶的催化效率提高，推荐其用于大规模动力学拆分光学活性仲醇。
