超顺磁性Fe_3O_4空心亚微球固定脂肪酶的研究  

Lipase immobilized on superparamagnetic hollow sub-microspheres of Fe_3O_4

作　　者：刘长霞[1] 刘曼丽[1] 张亚男[1] 谭天伟[1] 

机构地区：[1]北京化工大学生命科学与技术学院,北京100029

出　　处：《北京化工大学学报（自然科学版）》2013年第6期76-81,共6页Journal of Beijing University of Chemical Technology(Natural Science Edition)

摘　　要：采用溶剂热法合成磁性亚微米球,并且利用扫描电镜、透射电镜、傅里叶红外光谱仪、X-射线衍射仪、振动样品磁强计等对合成样品进行了分析表征,结果表明所获样品为平均粒径为350 nm的超顺磁性Fe3O4空心亚微球。对该样品进行了SiO2包覆或氨基硅烷修饰,分别将Fe3O4空心亚微球、SiO2包覆Fe3O4空心亚微球和氨基功能化Fe3O4空心亚微球作为固定化载体进行脂肪酶固定化。研究表明Fe3O4空心亚微球经SiO2包覆或氨基功能化后对脂肪酶的固载量分别提高3.2和4.0倍,固定化酶比活力提高2.9和3.4倍。固定化的最优条件为pH 6、25℃的条件下固定22 h。Superparamagnetic hollow sub-microspheres of Fe3 O4 （HMSF） with an average particle size of 350 nm were synthesized via a hydrothermal method, and then coated by SiO2 （ HMSF@ SiO2） or modified by aminosilanes （AHMSF）. Scanning electron microscopy （ SEM ）, transmission electron microscopy （ TEM ）, Fourier transform infrared spectroscopy （FT-IR） land vibrating sample magnetometry （VSM） were used to characterize the as-pre- pared samples. Lipases from Candida sp 99-125 were immobilized on HMSF, HMSF@ SiO2 and AHMSF. The a- mount and specific activity of immobilized lipases on HMSF @ SiO2 and AHMSF were well above that on bare HMSF, and AHMSF showed the best immobilization effect under the optimized conditions of pH 6, temperature of 25 ℃, and immobilization time of 22 h. Compared with bare HMSF, the amount of immobilized lipase was in- creased 3.2 times for HMSF@ SiO2 and 4.0 times for AHMSF and the specific activities were improved 2.9 times for HMSF@ SiO2 and 3.4 times for AHMSF.

关 键 词：超顺磁性 Fe3O4亚微球 SiO2包覆 氨基修饰 脂肪酶 固定化 

分 类 号：Q814.2[生物学—生物工程]