调控酶解底物初始pH制备低聚木糖

研究在木聚糖酶定向酶解纯木聚糖及木聚糖碱抽提液制备功能性低聚木糖时，酸和缓冲溶液调控底物的初始ｐＨ对低聚木糖的影响。结果表明，木聚糖酶在ｐＨ５．０左右的活力最高；酸调控纯木聚糖底物的低聚木糖得率低于缓冲溶液调控的低聚木糖得率，但两者相关不大；而当底物为木聚糖碱抽提液是，由于木素的存在，两种调控方式的低聚木糖得率相差较大，酶解液出现浑浊状态；酸调控纯木聚糖，木聚糖碱抽提液时，低聚木糖得率最高的初始ｐ

A Study on Regulating Initial pH Value of Substrate in the Process of Xylo-oligosaccharides Production

The effects of initial pH value of substrate controlled by acid and by buffer solution on the yield of enzymatic hydrolysis were studied when pure xylan and alkaline extractives were hydrolyzed selectively by xylanase for preparation of Xylo oligosaccharides.The experiments indicated the xylanase showed optimal activity at pH?5.0. At the same conditions for enzymatic hydrolysis, both pure xylan and alkaline extractives, the yield of oligosaccharide from the substrate hydrolyzed at acid controlled pH was lower than that at buffer solution controlled pH, but it was more obvious to alkaline extractives. Moreover,when the substrate was alkaline extractives, the transparence of supernatant liquid of enzymatic hydrolysate was opaque. The results of enzymatic hydrolysis showed that the optimal pH value controlled by acid for pure xylan and alkaline extractive was 4.8 and 6.0 respectively.