摘要
系统研究了由正庚烷、水、琥珀酸二辛酯磺酸钠 (AOT)所构成的油包水微乳液的百分组成、pH值、[H2 O]/[AOT]的比值 (ω0 )等对以此微乳液为基底的明胶固定化脂肪酶的活性及机械强度的影响 ,制备出了具有超高活性的微乳液凝胶固定化脂肪酶。此外 ,还对固定化酶的一些酶学特征进行了初步表征。最佳酶活对应的pH为 7 17,ω0 为 16左右。在恒定ω0 值下 ,酶活随AOT百分比的增加而提高 ,但机械强度正好相反。酶以酶粉形式直接加入微乳液中所得固定化酶的活性要比酶以酶液形式加入到AOT的正庚烷中所得的活性要高。微乳液凝胶固定化脂肪酶的活力大约是水固定化酶的 10倍 ,且在 4℃下其活性半个月内无明显变化。对中长链的脂肪醇或酸同系物 ,该固定化酶所显示出的底物选择性差异不大。
A water in oil (w/o) microemulsion composed of n heptane,water and sodium bis (2 ethylhexyl) sulfosuccinate (AOT) was used as a matrix for immobilizing a lipase from candida rugosa with gelatin Effects of the percentage composition,the pH value of phosphate buffer,and the molar ratio of water to AOT (ω 0) of the w/o microemulsion on the activity and the rigidity of the lipase containing microemulsion based gels (MBGs) were studied systematically Some physicochemical properties of the immobilized lipase on MBG were also studied Results showed that there was a optimum value for parameters pH and ω 0,which were found to be 7 17 and ca 16,respectively At a constant ω 0,the activity of the immobilized lipase increased with the increase of the weight percentage of AOT while the rigidity of the gel reduced In order to obtain a gel with high activity,the lipase powder instead of its buffer solution should be used to prepare the lipase containing microemulsion Under optimum conditions,the immobilized lipase on MBG had a rigid form as well as a high activity yield,and its activity remained almost unchanged when kept at 4℃ for half a month For fatty acids or alcohols with medium chain length,the immobilized lipase had approximately the same substrate selectivity
出处
《药物生物技术》
CAS
CSCD
2000年第2期93-97,共5页
Pharmaceutical Biotechnology
基金
山东大学微生物技术国家重点实验室
山东省自然科学基金资助!( 99112 2 80 1)
关键词
脂肪酶
微乳液
固定化
凝胶
胶束酶学
Lipase,Microemulsion,Immobilization,Microemulsion based gel, Enzyme characteristics
