响应面法优化乙二胺四乙酸二酐对草酸脱羧酶改性  

Response surface methodology to optimize the modification of oxalate decarboxylase by ethylenediaminetetraacetic anhydride

作　　者：史永桂 古再丽努尔 梁贺艳 林日辉 SHI Yong-gui;GUI Zailinuer;LIANG He-yan;LIN Rin-hui(School of Chemistry and Chemical Engineering,Guangxi University for Nationalities,Nanning 53006)

机构地区：[1]广西民族大学化学化工学院,南宁530006

出　　处：《中国食品添加剂》2020年第12期31-41,共11页China Food Additives

基　　金：国家自然科学基金项目(21766004);广西重大科技创新基地建设项目计划开放课题(2018-15-Z03-07);广西生物多糖分离纯化及改性研究平台建设项目(桂科ZY18076005);广西自然科学基金项目(2019GXNSFAA185008)。

摘　　要：为了提高草酸脱羧酶(Oxdc)在草酸钙(CaOx)上的酶稳定性和吸附性能,基于Box-Behnken设计(BBD)的响应面方法(RSM)的原理对乙二胺四乙酸二酐(EDTAD)修饰Oxdc的反应条件进行优化。建立了Oxdc摩尔比、反应时间、pH和反应温度对EDTAD的改性影响的数学模型,并研究了pH对EDTADOxdc的酶活性影响和吸附性能。结果表明,根据二次多项式的拟合分析和数学回归模型,实验结果与理论上最适修饰条件相吻合。在EDTAD与Oxdc的摩尔比为62∶1、时间为7.0h,pH为6.2和温度为25.0℃的最佳修饰条件下,EDTAD修饰的Oxdc的修饰率和酶活固定分别为70.23%±0.85%、82.06%±0.69%。pH实验结果表明,与Oxdc相比,EDTAD-Oxdc的最适pH向碱性方向移动约1.5个单位。吸附结果表明,与Oxdc相比,经EDTAD修饰的Oxdc对CaOx·H2O晶体的吸附能力提高31.13%。综上,EDTAD修饰可提高Oxdc的稳定性和吸附能力。In order to improve the enzyme stability and adsorption performance of oxalate decarboxylase(Oxdc)on calcium oxalate(CaOx),based on the Box-Behnken design(BBD)response surface method(RSM)principle,ethylenediaminetetraacetic dianhydride(EDTAD).Modification of Oxdc reaction conditions for optimization.A mathematical model of the effect of Oxdc molar ratio,reaction time,pH and reaction temperature on the modification of EDTAD was established.The effect of pH on the enzyme activity and adsorption performance of EDTAD-Oxdc was also studied.The results showed that,according to the second-order polynomial fitting analysis and mathematical regression model,the experimental results were consistent with the theoretically optimal modification conditions Under the optimal modification conditions that the molar ratio of EDTAD to Oxdc is 62∶1,the time is 7.0h,the pH value is 6.2 and the temperature is 25.0℃,the modification rate and enzyme activity immobilization of EDTAD modified Oxdc were 70.23%±0.85%,82.06%±0.69%.The results of pH experiments showed that,compared with Oxdc,the optimal pH value of EDTAD-Oxdc moves about 1.5 units to the alkaline direction.The adsorption results showed that,compared with Oxdc,the adsorption capacity of Oxdc modified by EDTAD on CaOx·H2O crystals is increased by 31.13%.In summary,EDTAD modification can improve the stability and adsorption capacity of Oxdc.

关 键 词：乙二胺四乙酸二酐 草酸脱羧酶 修饰 反应优化 

分 类 号：Q599[生物学—生物化学] Q814.9