产木聚糖酶菌种的筛选及其在纸浆漂白中的应用

摘要

The strains of high yield xylanase used in pulp bleaching were screened.A strain produced high xy-lanase is gained according to the ethanol hydrolysis circle method, and, its enzymatic properties are studied.Meanwhile, strains is made a preliminary identification, and enzyme in pulp bleaching applications are discussed.The results show that the screened bacteria activity is up to 642 U / mL, and is identified as one of Asper-gillus oryzae.The optimal temperature of bacterial producted enzyme is 50℃ , the best temperature of the activity is 50 t ,too, and pH was 5 to 6.The effect is best that kappa number was reduced from 32.3 to 25.5, and the whiteness increased significantly when xylanase dosage is 6 U/mL.%筛选出高产木聚糖酶的菌株,并将其应用于纸浆漂白.采用乙醇水解圈法筛出一株产木聚糖酶较高的菌种,并对其酶学性质进行了研究,同时对菌种做了初步鉴定,进一步探讨了其酶液在纸浆漂白中的应用.研究结果表明筛选得到的菌种酶活最高可达642 U/mL,经初步鉴定为米曲霉；菌体最适产酶温度为50℃,酶活最适温度为50℃,pH为5～6；当木聚糖酶用量为6U/mL时,效果达到最佳,卡伯值由32.3降低至25.5,白度由37.2提高到48.7,提高约31％.