【作者】 许君；

【导师】 贾新成； 陈红歌；

【作者基本信息】 河南农业大学 ， 微生物学， 2004， 硕士

【摘要】 从某造纸厂排水沟旁边的碱性土壤中，采集到要进行产酶菌种分离的土样，用RBB-Xylan选择培养基进行初筛，根据不同菌株所形成的透明圈的有无，决定需要复筛的菌株，经产酶基本培养基复筛后，筛选到一株碱性木聚糖酶高产菌株HNX01，其在基本产酶培养基中的产酶能力为80.39 IU/ml，根据其形态特征、运动性、培养特征及部分生理生化反应，初步鉴定该菌为芽孢杆菌（Bacillus.sp）。经单因子试验和正交设计试验，得出HNX01产酶的最佳条件为：玉米芯4%、麸皮2%、NH4Cl 0.6%、NaNO3 0.2%、K2HPO41%、土温80 0.2%、FeCl3 2mmol/L、pH8.0、接种量为3%、250ml三角瓶装液量为50ml 。37℃、220r/min下用此培养基培养HNX01 24小时，木聚糖酶酶活力达高峰值198.41IU/ml，是未经优化的产酶基本培养基产酶能力的2.5倍。HNX01所产木聚糖酶最适作用pH值为8.0，酶具有较宽的pH值耐受性，尤其是在pH7.0以上的碱性范围稳定性更好，在pH6.0~10.6之间木聚糖酶酶活力都在80%以上；最适作用温度为50℃，酶在20℃~50℃下基本稳定， 50℃处理60分钟仍然具有70%以上的酶活力。金属离子除Zn2+对酶有轻微的激活作用外，其它对酶活力都存在不同程度的抑制作用，其中Cu2+对木聚糖酶酶活力的抑制最强烈。更多还原

【Abstract】 According to RBB-xylan-hydrolyzed halos method , A bacterial strain which can produce extra-cellular alkaline xylanase, was isolated from alkaline soil near the drain ditch of a paper-producing factory .The strain was named as HNX01.The activity of xylanase produced by HNX01 was 89.39 IU/ml. According to its morphological characterization, physiological and biochemical experiments, HNX01 should belong to Bacillus.sp.After single factor tests and orthogonal array ,the optimal medium consisted of 4% corn power, 2% wheat bran, 0.6% NH4Cl, 0.2% NaNO3, 1% K2HPO4, 0.2% tween-80, 2mmol/L FeCl3.The initial pH of medium was 8.0.The percent of inoculation was 3%.The volume was 50ml in 250ml flask.After shaken at 220rpm and cultured in this optimal medium for about 24 hours at 37℃ , the xylanase activity is 198.41 IU/ml, which is 2.5 times of original medium.The xylanase from HNX01 displayed an optimal temperature at 50℃ and optimal pH at 8.0,a pH stability range from 5.0 to 10.6 and thermal stability up to 50℃.After incubated for 60 minute at 50℃,it still had 70% activity. In the metal ions investigated, only Zn2+ promoted effects on Xylanase, other ions all inhabited its activity more or less. Especially, Cu2+ inhabited almost all the activity. Fe3+ inhabited 50% activity in the enzyme reaction.更多还原