混合非淀粉多糖水解酶酶活测定方法的改进

Improvement of the Activity Determination of Complex Nonstarch Polysaccharides Hydrolases

用分光光度法分别准确地测定了混合非淀粉多糖水解酶中木聚糖酶、果胶酶、β -葡聚糖酶和纤维素酶的酶活。但将酶添加到物料中后 ,酶活测定变得非常困难 ,于是对酶活测定方法进行了改进。利用凝胶过滤色谱法对酶液进行预处理 ,排除了体系中还原糖等小分子量杂质的干扰 ;采用琼脂放射扩散法测定纤维素酶或 β -葡聚糖酶酶活 ,提高了测定的特异性和灵敏度 ;利用专一性的酸性醋酸铜法测定果胶酶酶活 ,提高了特异性 ;采用硫酸铵沉淀法处理木聚糖酶 。

The activities of the nonstarch polysaccharide hydrolases, including xylanase, pectase, β-glucanase and cellulase, in a premixed enzyme preparation were determined accurately by spectrophtometry. But when the premixed preparation was added into edibles, the enzyme activities could not be determined individually with accuracy. Some improvements of the determining methods were made as follows. Firstly, the enzyme solution was pretreated by gel filtration in order to remove fractions with low molecular weight, such as reducing sugar. Secondly, through the agar radial diffusion, the sensitivity and specificity of β-glucanase and cellulase activity determination were improved greatly. In addition, the determining method of pectase activity was changed to more sensitive and specific by using acidic copper acetate. Finally, through ammonium sulfate precipitation, the interference of other enzymes to xylanase activity determination was eliminated.