铁氨基黏土纳米结构脂肪酶的构筑及催化特性

Construction and Catalytic Performances of Fe-aminoclay Nanostructured Lipase

以铁氨基黏土(Fe-aminoclay)为载体,1-(3-二甲氨基丙基)-3-乙基碳二亚胺盐酸盐(EDC)为共价交联剂,构筑了铁氨基黏土纳米结构脂肪酶催化剂(Feclay-lipase).利用X射线衍射(XRD)、透射电子显微镜(TEM)和傅里叶变换红外光谱(FTIR)等技术对Feclay-lipase进行了表征,并通过酶动力学对比研究了游离脂肪酶和Feclay-lipase的酶学特性.结果表明,Fe-aminoclay的载酶量为414. 4 mg/g,固定化效率可达82. 88%,Feclay-lipase的酶活较游离酶提高了3倍,最适反应温度提高了10℃,最适反应p H向碱性偏移,储存稳定性更好,在4℃下贮存30 d后其酶活无明显减弱.

Lipase from Aspergillus oryzae was immobilized on Fe-aminoclay support via 1-( 3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride( EDC) as covalent crosslinking agent. The nanocomposite structure of immobilized lipase( Feclay-lipase) was characterized by means of X-ray diffraction( XRD),transmission electron microscope( TEM) and Fourier transform infrared spectroscopy( FTIR). The enzymatic properties of free lipase and Feclay-lipase were studied by enzymatic kinetics. The results showed that the optimal immobilization efficiency of Feclay-lipase was 82. 88%,immobilization capacity was 414. 4 mg/g support,and the enzyme activity was 28. 24 U/mg,which was three times higher than that of free lipase( 8. 21 U/mg).The optimum reaction temperature of Feclay-lipase increased from 45 ℃ to 55 ℃,the optimum pH shifted to alkalinity,and the catalytic activity of Feclay-lipase did not decrease significantly after storage at 4 ℃ for one month.