不同来源木聚糖酶在模拟胃液和肠液中的稳定性评价

Studies on the stability of xylanase in simulated gastric fluid and simulated intestinal fluid

试验研究了市售8种不同来源木聚糖酶在模拟胃、肠液中的稳定性。分别将不同来源木聚糖酶产品在模拟胃、肠液中培养0、1、2和3 h后测定其酶活存留率,用以评估不同来源木聚糖酶在模拟胃、肠液中的稳定性。结果表明:8种木聚糖酶在模拟胃、肠液中的稳定性差异较大,在模拟胃液中,耐受性最好的是酶Ⅳ、酶Ⅶ和酶Ⅷ,3 h后存留率分别为:105%、98%和106%;耐受性最差的为酶Ⅰ,3 h后存留率仅为4%;在模拟肠液中,耐受性最好的是酶Ⅰ,3 h后存留率为99%;耐受性最差的为酶Ⅳ,3 h后存留率为44%。

The stability of xvlanase in simulated gastric fluid （SGF） and simulated inlestinal fluid （SIF） by spectrophotometer were investigated to provide a reference to determine the quality of different xvlanase products. Xylanase products were mixed with SGF（2 mg/ml NaCI, pH 2.0. Pepsin Sigma P6887） or SIF（0.05 M KH2PO4, pH 6.8, Panereatin Sigma P1750） （37 ℃） and the reactions were terminated at different time intervals （I h, 2 h and 3 h）. The activity of xvlanase in the soh,tion was delecled by the Megazyme method. The resuh showed that the stability of 8 xylanases is significantly different. In SGF the best stability was found for enzymeIV, enzyme Ⅶ and enzyme Ⅷ with retention rate of activity after 3 h incubation being 105%, 98%. 106%. respectively. Enzyme I had the lowest retention rate of activity after 3 h, only 4%; In SIF enzyme I is the most stable prodt,et with retention rate of activity of 99%. after 3 h incubation. However. enzvme Ⅳ had a retention rate of activity-only 44% after 3 h incubation.