具有益生功能芽孢杆菌的筛选鉴定及特性研究

Bacillus with Probiotic Function:Screening,Identification and Characterization

本研究旨在筛选出产酶能力及抑菌性能优良的发酵菌株,为新型饲料资源的开发和抗生素替代品的研究提供参考。以蜡样芽胞杆菌菌株H14为出发菌株,分析其酶学特性和抑菌性能,通过单因素试验对发酵菜籽粕的饲料添加量与发酵时间进行优化。筛选鉴定出一株产纤维素酶、蛋白酶、淀粉酶、木聚糖酶的蜡样芽胞杆菌H14。产纤维素酶最适反应条件为60℃,pH 9,酶活11.51 U/mL,蛋白酶酶活73.68 U/mL,淀粉酶酶活5.96 U/mL,木聚糖酶酶活14.02 U/mL。对大肠杆菌和金黄色葡萄球菌最大抑菌直径分别为18.200±0.200 mm和17.567±0.493 mm。发酵菜籽粕产纤维素酶的最佳条件为菜籽粕添加量25%,发酵48 h,酶活为12.608 U/mL,对大肠杆菌和金黄色葡萄球菌的最佳抑菌效果分别为菜籽粕添加量25%,发酵48 h,抑菌直径为24.933±0.204 mm;菜籽粕添加量25%,发酵72 h,抑菌直径为27.400±0.529 mm,发酵产物含蔗糖、木糖、葡萄糖。综上所述,本研究成功筛选出一株具有良好产酶和抑菌特性的发酵菌株H14,其在发酵菜籽粕生产中表现出良好的应用潜力,为未来发酵饲料的研发提供了有价值的参考。

The aim is to obtain the fermentation strains with remarkable ability to produce enzyme and antibacterial property,and provide reference for the conversion of new feed resources and the search for antibiotic substitutes.Using strain H14 as the starting point,its enzymatic property and antibacterial ability were analyzed.The feed addition and fermentation time of fermented rapeseed meal were optimized by single factor experiments.A strain of Bacillus cereus H14 that produces cellulase,protease,amylase,and xylanase was screened and identified.The optimal reaction conditions for cellulase production were 60℃ and pH 9,and theactivityofcellulase,protease,amylaseandxylanasewas 11.51U/mL,73.68U/mL,5.96U/mLand 14.02U/mL respectively.The maximum inhibitory diameters against Escherichia coli and Staphylococcus aureus were 18.200±0.200 mm and 17.567±0.493 mm,respectively.The optimal conditions for fermenting rapeseed meal to produce cellulase were adding 25% rapeseed,incubating for 48 h,enzyme activity reached 12.608 U/mL,and the optimal antibacterial effects on Escherichia coli and Staphylococcus aureus were adding 25% rapeseed meal and incubating for 48 h,the antibacterial diameter(mm)was 24.933±0.204;and adding 25% rapeseed meal and incubating for 72 h,the antibacterial diameter(mm)was 27.400±0.529,respectively.The fermentation products contain sucrose,xylose,and glucose.This experiment screened out a good fermentation strain,which could provide some reference for the development of fermented feed.