微孔陶瓷固定化酶载体的合成

Fabrication of microporous ceramic supports for enzyme immobilization

据絮凝沉淀物的三维网状结构成孔的原理,开发了制备微孔陶瓷的一种新方法.该方法工艺简单、环保节能,孔径可在微米级和纳米级之间调节.微米级陶瓷孔径介于10～100μm范围,气孔率达53%～59%,容重为0.97～1.10g·cm-3,抗压强度达到6.0MPa以上.用压汞仪对纳米级微孔陶瓷抽样测定,平均孔径为76nm,比表面积5.90m2·g-1,孔容0.12ml·g-1,孔径呈双峰分布.以脂肪酶为例,考察了块状微孔陶瓷用作固定化酶载体的性能.结果表明,当对微孔陶瓷作适当的表面改性以后,固定化脂肪酶的活性高于其他一些常见的无机吸附剂载体,间歇操作5次后仍然保持其初始活性的60%左右.

A new method was developed for the fabrication of porous ceramics by using the special three- dimensional reticulate framework formed by the groups of flocculent raw particles in the deposit. The size of pore diameter could be controlled between micron and nanometer scale. For the former, the pore diameter was about 10 to 100 μm, the apparent porosity ranged from 53 % to 59 %, the bulk density from 0.97 to 1.10 g ·cm^-3, and the crushing strength above 6.0 MPa; for the latter, measured by the mercury intrusion method, the average pore diameter was about 76 nm, and the total surface area 5.90 m^2·g^-1. With commercial Penicillium expansum lipase （PEL） as model enzyme, the performance of the porous ceramic supports was investigated in relation to the activity and stability of immobilized enzyme. The results indicated that the microporous ceramics prepared by the present method could potentially be better inorganic supports for enzyme immobilization than some other commercial inorganic solid supports like silica accor gel, diatomite and active carbon, on the condition that its pore surface was suitably modified ding to the property of the enzyme.