Enhancing enzyme activity and enantioselectivity of Burkholderia cepacia lipase via immobilization on modified multi-walled carbon nanotubes
Enhancing enzyme activity and enantioselectivity of Burkholderia cepacia lipase via immobilization on modified multi-walled carbon nanotubes
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DOI：
10.1039/c4ra10517f
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发表时间：
2014-11
期刊：
影响因子：
3.9
通讯作者：
C. Ke;Xiang Li;Shuangshuang Huang;Li Xu;Yunjun Yan
中科院分区：
文献类型：
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作者：
C. Ke;Xiang Li;Shuangshuang Huang;Li Xu;Yunjun Yan
洋葱伯克霍尔德菌脂肪酶（BCL）被证明是一种潜在的手性拆分催化剂。但由于游离脂肪酶的催化活性低、稳定性差等原因，使其在工业上的应用受到限制。本研究将BCL固定在改性的多壁碳纳米管上，以提高其催化性能。通过单因素试验和响应面分析法对固定化条件进行了优化。在最佳条件下，酶活为50 ~ 200 U g-1，是游离脂肪酶拆分1-苯基乙醇的54倍，反应时间从游离脂肪酶的30 h大大缩短到固定化脂肪酶的10 min。SEM显微照片证实，碳纳米管被截断，封闭端被打开浓硫酸。EDS进一步证实了脂肪酶的修饰和成功的固定化。FT-IR分析表明，酶活性和ees的提高与二级结构的改变有关。与其他固定化脂肪酶相比，CNT-BCL具有很大的优势，具有很好的工业应用前景。
Burkholderia cepacia lipase (BCL) was proved to be a potential catalyst in chiral resolution. However, it is not widely applied in industry because of the low catalysis activity and poor stability of the free lipase. In this study, BCL was immobilized on modified multi-walled carbon nanotubes to enhance its catalysis performance. The immobilization conditions were further optimized via single factorial experiments and response surface methodology (RSM). Under the optimum conditions, the enzyme activity attained was 50 200 U g−1, 54 fold that of the free lipase in resolution of 1-phenylethanol, resulting in an immensely shortened reaction time from 30 h of the free lipase to 10 min of the immobilized one. SEM micrographs verified that CNTs were truncated and the closed ends were opened by concentrated H2SO4. EDS further confirmed the modification and successful immobilization of the lipase. FT-IR analysis demonstrated that improvement of enzyme activity and ees was correlated to the alteration of the secondary structure. Compared with other immobilized lipases, CNT–BCL exhibits great advantages and possesses promising potential in industrial application.