棉杆木聚糖碱法提取及酶解制备低聚木糖研究

摘要

The conditions of water insoluble cotton stalks xylan extraction with alkali method was studied by single factor test and orthogonal experiments of L9 (34).The effects of pretreatment temperature,time of extraction,NaOH concentration and cotton stalks to NaOH solution ratio were studied.The yield of water insoluble xylan was up to 46.79％ when the conditon was 80C,4h,15％,1 ∶ 20.The xylanase L10904 were used in preparation of xylooligosaccharides by enzymatic hydrolysis and conditions were optimized via response surface Box-Benhnken central composite experimental design.A high yield of reducing sugarof 31.04％ was obtained when the conditions were as follows:substrate concentration 0.86％,enzyme amount 20.0U/mL,hydrolysis temperature 53℃ and hydrolysis time 240min.TLC analysis showed that the main components are xylobiose and xylotriose.%通过单因素及正交试验确定了棉杆中水不溶性木聚糖最佳提取条件:预煮温度80℃,碱液浓度15％,料液比1∶20,浸提时间4h,在此条件下棉杆木聚糖的提取得率为46.79％.对实验室保存产木聚糖酶优良菌株筛选,确定真菌L10904产木聚糖酶为制备低聚木糖水解用酶.通过单因素及响应面法考察酶解最佳条件,结果显示:底物浓度0.86％,酶的添加量20.0U/mL,温度53℃,水解240min条件下低聚木糖得率可达31.04％.对酶解产物进行TLC分析结果表明其主要成分是木二糖和木三糖.