无溶剂体系中毕赤酵母表面展示CALB全细胞催化合成肉桂醇酯

Synthesis of Cinnamic Alcohol Ester Catalyzed by Candida Antarctica Lipase B-Displaying Pichia Pastoris Whole-cells in Solvent-free System

利用表面展示南极假丝酵母脂肪酶B(Candida antarctica lipase B,CALB)的毕赤酵母细胞(Pp-CALB)为全细胞催化剂,以不同脂肪酸作为酰基供体,在无溶剂体系中和肉桂醇发生酯化反应合成肉桂醇酯。探究了Pp-CALB对于不同酰基供体的选择性,并且对反应温度、摇床转速、酶加量、底物摩尔比、酶的水活度和反应体系等一系列影响酶催化反应的因素进行了优化,建立了无溶剂体系中肉桂醇酯的酶法合成工艺。结果表明,在底物摩尔比为2:1,摇床转速为120 r/min,反应温度为50℃的条件下,添加初始水活度为0.53的Pp-CALB 0.05 g,反应3h,肉桂醇的酯化率可达81.34%,在最适反应条件下,使用Pp-CALB连续反应8次后,肉桂醇的酯化率仍然能达到70.00%以上,具有较好的操作稳定性。

Cinnamic alcohol ester were synthesized with cinnamic alcohol in solvent-free system using Candida antarctica lipase B-displaying Pichia pastoris whole-cells as catalyst and fatty acids as acyl donors. The selectivity of Pp-CALB for acyl donors was investigated, and the reaction temperatures, agitation speeds, enzyme dosage, molar ratio of substrates, initial water activity of Pp-CALB and reaction system were optimized to establish enzymatic synthesis process of cinnamyl alcohol ester in solvent-free system. The optimal reaction conditions were as follows： reaction temperature was 50 ℃, molar ratio of acid to alcohol was 2：1, agitation speed was 120 r/min, initial water activity of Pp-CALB was 0.53, and enzyme loading was 0.05 g. The reaction conversion reached 81.34% under the optimal conditions sysnthsized for 3 h, which could still reach more than 70.00% after 10 cycles of continuous reaction with Pp-CALB, indicating the good operational stability.