木聚糖酶分级对高温降解木聚糖酶水解的影响

为提高酶解液中聚合度为2～5的低聚木糖含量，采用超滤的方法对木聚糖酶进行分级，用于高温降解木聚糖的酶水解。结果表明：木聚糖酶原酶液经超滤分级后，得到的木聚糖酶A组分（分子质量为30～50 ku）、B组分（分子质量为10～30 ku）和C组分（分子质量小于10 ku），均能使木聚糖中聚合度较高的糖降解为聚合度为2～5的低聚木糖。木聚糖酶B组分由于富含内切木聚糖酶XYN I和XYNⅡ，1 mg酶蛋白可以产生263 g木二糖、185 g木三糖、115g木四糖和046 g木五糖，明显高于木聚糖酶A和C组分高温降解木聚糖的水解能力。

Enzymatic hydrolysis of high-temperature degraded xylan with xylanase

In order to increase xylo-oligosaccharides in the enzymatic hydrolysate with a degree of polymerization(DP) between 2 and 5,crude xylanase was ultrafiltrated to hydrolyze high-temperature degraded xylan.The results showed that three xylanase components,named xylanase A(MW 30—50 ku),xylanase B(MW 10—30 ku) and xylanase C(MW<10 ku),were obtained after ultrafiltration fraction of crude xylanase.These xylanase components were able to hydrolyze the high-temperature degraded xylan efficiently to xylo-oligosaccharides with a DP between 2 and 5.Xylanase B performed much better than xylanase A and C;1 mg protein of xylanase B could produce xylobiose 2.63 g,xylotriose 1.85 g,xylotetraose 1.15 g and xylopentaose 0.46 g.