Badgujar Kirtikumar C, Bhanage Bhalchandra M
Department of Chemistry, Institute of Chemical Technology, Matunga, Mumbai 400 019, India.
Department of Chemistry, Institute of Chemical Technology, Matunga, Mumbai 400 019, India.
Enzyme Microb Technol. 2014 Apr 10;57:16-25. doi: 10.1016/j.enzmictec.2014.01.006. Epub 2014 Jan 22.
This work reports the use of new support for immobilization of lipase Burkholderia cepacia (BCL) matrix made up of polylactic acid (PLA), chitosan (CH), and polyvinyl alcohol (PVA). Initially lipase from various microbial sources and immobilization support composition was screened to obtain a robust biocatalyst. Among various biocatalysts preparation, the PLA:PVA:CH:BCL (1:6:1:2) was worked as a robust biocatalyst for the citronellyl acetate synthesis. Various reaction parameters were studied in detail to obtain the suitable reaction conditions for model citronellyl acetate synthesis reaction. Various kinetic parameters such as r(max), K(i(citronellol)), K(m(citronellol)), K(m(vinyl acetate)) were determined using non-linear regression analysis for the ternary complex as well as bi-bi ping-pong mechanism. The experimental results and kinetic study showed that citronellyl acetate synthesis catalyzed by immobilized lipase BCL followed the ternary complex mechanism with inhibition by alcohol (citronellol). The energy of activation for citronellyl acetate synthesis was found to be lower for immobilized lipase (8.9 kcal/mol) than aggregated lipase (14.8 kcal/mol) enzyme. The developed biocatalyst showed four to fivefold higher catalytic activity and excellent recyclability (up to six cycles) than the aggregated lipase.
本研究报道了一种新型载体，用于固定由聚乳酸（PLA）、壳聚糖（CH）和聚乙烯醇（PVA）组成的洋葱伯克霍尔德氏菌脂肪酶（BCL）基质。最初，对来自各种微生物来源的脂肪酶和固定化载体组成进行了筛选，以获得一种强大的生物催化剂。在各种生物催化剂制备方法中，PLA:PVA:CH:BCL（1:6:1:2）作为乙酸香茅酯合成的强大生物催化剂。详细研究了各种反应参数，以获得模型乙酸香茅酯合成反应的合适反应条件。使用非线性回归分析确定了三元复合物以及双底物乒乓机制的各种动力学参数，如r(max)、K(i(香茅醇))、K(m(香茅醇))、K(m(乙酸乙烯酯))。实验结果和动力学研究表明，固定化脂肪酶BCL催化的乙酸香茅酯合成遵循三元复合物机制，并受到醇（香茅醇）的抑制。发现固定化脂肪酶催化乙酸香茅酯合成的活化能（8.9千卡/摩尔）低于聚集脂肪酶（14.8千卡/摩尔）。所开发的生物催化剂比聚集脂肪酶表现出高四到五倍的催化活性和优异的可回收性（高达六个循环）。
