Antibacterial Activity of Bacillus subtilis and Properties of Protein Crude Extract

枯草芽孢杆菌抑菌活性及蛋白粗提物特性研究（英文）

In order to get biological drugs with no resistance or toxic side effects and to reduce the use of antibiotics, a strain of Baci//us subtilis was isolated from animal intestine, and the isolate was identified by molecular biological method; in vitro an- tibacterial test of the isolate was performed using agar diffusion method; the optimal fermentation condition of the isoJate was screened by conventional culture method; the antibacterial crude protein of the isolate was extracted by saturated ammonium sulfate method; the physicochemical properties of antibacterial crude protein was de- tected by comparison method; The results showed that the isolate was B. subti/is, which had antibacterial effects on Staphy/ococcus aureus, streptococcus and swine erysipelas. The fermentation effect of the isolate was the best under the condition of temperature 30 ~C, pH 7, liquid volume 75 ml/250 ml, inoculation volume 20% and culture time 48 h. The antibacterial effect of the isolate was the best when extract- ed by 80% saturated ammonium sulfate. The antibacterial crude protein had strong resistance to heat and acid. Organic solvent and UV irradiation had some influences on antibacterial crude protein. Proteases had hydrolytic effects on antibacterial crude protein. The isolated B. subti/is can be used to prevent and control the diseases caused by S. aureus, streptococcus and swine erysipelas, and can regulate intesti- nal microecology by adding into expanded feeds.

为了获得无耐药性、无毒副作用的生物药物,减少抗生素的使用,从动物肠道中分离到一株芽孢杆菌,用分子生物法鉴定分离菌;用琼脂扩散法做分离菌体外抑菌试验;用常规培养法筛选分离菌最佳发酵条件;用饱和硫酸铵法提取分离菌抑菌粗蛋白;用比对法检测抑菌粗蛋白的理化特性;鉴定分离菌为枯草芽孢杆菌;对金黄色葡萄球菌、猪丹毒、链球菌有抑菌作用;当温度为30℃、酸碱度为pH7、装液量为75 ml/250 ml、接种量为20%、培养时间为48 h,分离菌发酵效果最好;用80%饱和硫酸铵提取抑菌粗蛋白的方法最好;抑菌粗蛋白有较强的抗热和抗酸能力;有机溶剂、紫外照射对抑菌粗蛋白有一定的影响;蛋白酶类对抑菌粗蛋白有一定的水解作用。所分离的枯草芽孢杆菌可用于防治因金黄色葡萄球菌、猪丹毒、链球菌等引起的疾病,也可加到膨化饲料中用于肠道微生态的调节。