【摘要】 采用富集培养、透明圈平板筛选 ,从长期在其上堆放秸秆的土壤中分离到一株木聚糖酶产生菌黑曲霉C2。对该菌株进行紫外线诱变处理 ,然后采用自然选育的方法筛选到一株木聚糖酶高产菌株C2 - 5 6 ,并对该菌株的适宜发酵条件和酶学特性进行了初步研究。结果表明 ,C2 - 5 6三角瓶发酵酶活达 6 5 6 .8U/g ,比出发菌株C2提高了 14 0 % ;发酵条件以 80 %麸皮和 2 0 %玉米芯为培养基 ,采用 3%接种量 ,在曲盘上发酵 72h为宜 ,酶活达 175 0U/g ;该菌株产生的木聚糖酶具有较差的热稳定性和较好的pH稳定性 ,适宜反应温度和pH分别为 5 0℃和pH4 .2。更多还原

【Abstract】 By enriching culture,hydrolysis ring,a xylanase producing strain,Aspergillus niger C2 was screened from the soil on which crop straw was put around year.C2 was treated by UV light,a high yield xylanase producing strain C2-56 was selected.Itsproper conditions for fermentation and reaction were studied also.Results indicated,by flask solid fermentation,its xylanase activity was 656.8 U per gram dry medium,140% higher than that of original strain C2.The proper fermentation wae:by koji plate fermentation,inoculum size of 3%,the xylanase activity was up to 1750 U per gram dry medium after 72 hours cultured on medium composed of 80% wheat bran and 20% corn-cob.Xylanase produced by C2-56 was sensitive to high temperature and resistant to pH value,its optimal temperature and pH value was 50℃ and pH 4.2 respectively.更多还原