产纤维素酶的解淀粉芽孢杆菌分离鉴定及酶学性质研究

对一株产纤维素酶菌株进行分离鉴定,并对其酶学特性进行了初步研究.刚果红染色法筛选产纤维素酶菌株B16,采用形态观察、生理生化指标和16S rDNA确定其菌属来源,分析纤维素酶的最适反应pH值和温度、酸碱和热稳定性、金属离子对酶活性的影响,最后考察纤维素酶系的分布.结果表明:筛选菌株为解淀粉芽孢杆菌,其较适反应温度为30℃,较适pH 8.0,在10~60℃呈高稳定性,在pH 5~8时稳定性较强,Mn2+和Ba2+是该酶的激活因子.除微晶纤维素酶活力(16.39 U/mL)稍弱外,滤纸酶(70.37 U/mL)、β-葡萄糖苷酶(131.55 U/mL)、羧甲基纤维素酶(307.23 U/mL)活力均相对较高.结果表明,该酶在饲料添加剂方面具有应用潜力.

Screening and Identifying of Bacillus amyloliquefaciens for Cellulase Production and its Enzymatic Characters

A cellulase-produeing strain was isolated and identified and their enzymatic characters were analyzed. The selected strain straining with congo red was studied with the morphological, physiological and biochemical characteristics as well as 16S rDNA sequence homology. Moreover, the effecting factors for the cellulase activity, such as optimal temperature, optimal pH, pH stability, and thermal stability and effects of metal ions were studied. Finally, the distribution of cellulase system was examined. The results indicated that the strain is Bacillus amyloliquefaciens and the optimal temperature and pH was 30 ℃and pH 8.0. Higher stability of the cellulase was obtained at 10 - 60 ℃ and pH stability was better at pH 5 - 8. Mn2 ＋ and Ba2 ＋ were the activated factors for the enzyme. The activity of CMCase,FPcellulase and β-glucosidase were 307.23 U/mL, 70.37 U/mL, and 131.55 U/mL, respectively, which had higher cellulase activity expect as avicelase （16.39 U/mL）. So the results suggested that the cellulase from Bacillus amyloliquefaciens had potential applications in the feed additive.