微量测定木聚糖酶活力的新方法——MBTH法  

A Novel Method for Determining Trace Amounts of Xylanase Activity: MBTH

作　　者：张永勤[1] 王斐[1] 曾凡伟[1] 王哲平[1] 张杰[1] 赵鑫[1] 程千[1] 

机构地区：[1]青岛科技大学化工学院,山东青岛266042

出　　处：《食品科学》2012年第3期44-47,共4页Food Science

摘　　要：建立一种木聚糖酶活力的微量测定新方法——3-甲基-2-苯并噻唑酮腙(MBTH)法。根据木聚糖及其酶解产物的特殊性,研究MBTH法的显色条件,并以多点测定法对酶活力测定中的几个关键参数进行探讨。结果表明:蛋白质在其质量浓度低于30μg/mL时对测定无干扰;木聚糖溶液的最佳测定质量浓度为4mg/mL;较高的酶解温度会使木聚糖酶在测定过程中失活,因此,酶活力测定的最佳温度为30℃,而远低于该酶的最适温度;酶解时间为60min以内;酶解产物与MBTH试剂的反应时间应控制在13～16min之间,以15min为最佳。以酶解时间为30min计,本法检测限为0.135mU/mL,定量限为0.451mU/mL,适当延长酶解时间可相应提高酶活力检测灵敏度。该法准确度高,结果稳定,灵敏度远高于DNS法。A novel method for the quantitative determination of trace amounts of xylanase activity was established. The chromogenic conditions were explored according to the properties of xylan and its hydrolysates. The effects of several key hydrolysis parameters on the determination of xylanase activity were investigated by multiple-point procedures. The results showed that protein concentrations less than 30 μg/mL did not interfere with the determination of xylanase activity. The optimal xylan concentration for the determination of xylanase activity was 4 mg/mL. High hydrolysis temperatures could inactivate xylanase. The most appropriate temperature for determining xylanase activity was 30 ℃, much lower than the optimal reaction temperature. The hydrolysis time was controlled within 60 min. The reaction time between hydrolysates and MBTH reagent was 13 - 16 min with the optimal level of 15 min. Based on 30 min hydrolysis, the detection limit and quantitation limit of the method were 0.135 mU/mL and 0.451 mU/mL, respectively. Properly prolonged hydrolysis time could improve the sensitivity of the method. The method was accurate, stable and even more sensitive than the DNS method.

关 键 词：木聚糖酶 MBTH 活力 木聚糖 木糖 测定 

分 类 号：Q814.9[生物学—生物工程]