产木聚糖酶但无纤维素酶活性菌株的筛选及初步鉴定

摘要

In order to obtain a strain with cellulase-free xylanase activity,a bacterium named as 26T was isolated from paper mill wastewater by substrate screening.The strain 26T was preliminarily identified as Bacillus subtilis by analyzing its physiological and biochemical characteristics and 16S rDNA gene sequence.This strain could grow under the conditions of 50 ℃ and pH 10,and revealed high heat and alkali resistance.The xylanase from it as an extracellular enzyme had an activity of 14.58 U/mL under the optimal fermentation conditions of 37 ℃,200 r/min and 12 h.Therefore,this strain might have a prosperous application in food industry.%为获得产木聚糖酶但无纤维素酶活性的菌株,本实验以造纸污水为分离材料,使用底物筛选法得到一株目标菌株,命名为26T。通过生理生化及分子生物学鉴定,初步判定其为枯草芽孢杆菌（Bacillus subtilis）。该菌株在50℃、pH10.0的环境中生长良好,有较好的耐热、耐碱性,其产生的木聚糖酶主要分布在细胞外,并且37℃、200r/min摇瓶发酵12h后酶活力可达14.58U/mL,该菌株在食品工业中具有很好的应用潜力。