木聚糖酶在膜反应器内的酶解特性

Enzymatic Hydrolysis Characteristics of Xylanases in Ultrafiltration Membrane Reactor

分别研究了粗木聚糖酶和纯化的木聚糖酶在超滤膜反应器（UMR）和常规反应器（CSBR）中的酶解特性。粗木聚糖酶或纯木聚糖酶在UMR中酶解木聚糖时，反应进行了525min时所得产品中低聚木糖各组分的质量分数（木二糖～木五糖）均在20％左右，木糖质量分数约为9．5％。在UMR中粗木聚糖酶降解木聚糖时的低聚木糖得率、低聚木糖占总糖的比例和低聚木糖生产能力比纯木聚糖酶在CSBR中分别高19．1％、14．8％和13．5％；而木糖的得率却低55．2％。粗木聚糖酶在UMR中酶解木聚糖时，所得低聚木糖产品中木二糖～木五糖组分含量基本相等；纯木聚糖酶在CSBR中酶解木聚糖时，所得低聚木糖产品中木二糖含量较高。同纯木聚糖酶在CSBR中酶解特性相比，粗木聚糖酶在UMR中酶解木聚糖可以制得高质量低聚木糖。

It was comparatively investigated that xylan was hydrolyzed by crude and purified xylanases in uhrafihration membrane reactor （UMR） and conventional stirring batch reactor （CSBR）. After enzymatic hydrolysis of 525 min in UMR using crude or purified xylanases,the obtained individual oligosaccharide components （ xylobiose, xylotriose, xylotetraose, and xylopentaose） in the hydrolysates accounted for some 20 % respectively, and xylose about 9.5 %. The xylo-oligosaccharide yields, the ratio of xylo-oligosaccharides to total saccharides, and the productivity of xylo-oligosaccharides in UMR using crude xylanases were 18.7 %, 14.9 % and 16.0 % higher than those in CSBR using purified xylanases, respectively, but xylose yield was 55.5 % lower than that in the latter case. The amount of individual oligosaccharide component in UMR was almost equal in the UF membrane reactor using crude xylanases, and more xylobiose was obtained in the CSBR using purified xylanases. Therefore, high-quality xylo-oligosaccharides could be prepared using crude xylanase in UMR.