滴定法快速测定发酵液中植酸酶活性

A direct titration method for a rapid determination of phytase activityin fermentation broth

目前植酸酶发酵液中植酸酶活测定方法主要采用比色法,但此方法受到发酵液中磷的严重干扰,大大降低了检测的准确性。为避免传统方法中磷对检测过程的影响,笔者基于酶活性可用单位时间、单位体积中底物的减少量来表示的原理,通过自动滴定检测植酸钠浓度变化并建立分析模型计算出植酸酶活性。结果显示:在200~1000 U/mL范围内,不同酶活单位的标准植酸酶酶解底物前后滴定时间差值与酶活单位大小成正相关(R^(2)=0.9905)。此外,利用滴定法和国标法同时测定植酸酶酶活性,两者呈明显线性相关(R^(2)=0.9728)。本研究建立的植酸酶活性测定方法耗时短、简单、易操作,对工业生产中植酸酶活性快速、准确测定具有重要意义。

Currently,the direct colorimetric assay for phytase activity was seriously interfered with the inorganic orthophosphate in phytase fermentation samples,resulting in large variation and poor reproducibility for phytase activity determination.To overcome this problem,based on the principle that the phytase activity could be defined as the decrease amount of substrate per unit time and volume,we established a direct titration method by automatically titrating the sodium phytate and establishing analytical model to calculate the phytase activity in fermentation broth in this study.The results demonstrated that a linear correlationship between titration time and standard phytase activity in the range of 200-1000 U/mL was observed(R^(2)=0.9905),in addition,the phytase activity determined with this method was linearly dependent to that determined with national standard method(R^(2)=0.9728).In conclusion,the direct titration method was time-saving,simple and user-friendly,which made it possible for rapid and accurate phytase activity determination in large scale fermentation industry.