5株芽孢杆菌的分离鉴定、拮抗性试验与抑菌效价测定

Identification, Isolation, Antibiotic and Curb Activity Experiments of Five Antagonistic strains of Bacillus cereus

通过对采集样品中细菌的分离与纯化,获得5株芽孢杆菌,经纯化培养后观察其个体和群体形态特征,并进行了16项生理生化特征鉴定。结果表明,L1为地衣芽孢杆菌、L2为蜡样芽孢杆菌、L3为短小芽孢杆菌、L4为蜡样芽孢杆菌、L5为蜡样芽孢杆菌;通过对5株指示菌的拮抗试验,确定了它们的抑菌图谱;从中挑选出拮抗性最强的两株菌,采用平板琼脂扩散法,测定了其发酵液的抑菌效价。在30℃,pH7.0,150r/min的条件下,恒温振荡培养24h,测其发酵液的抑菌效价:L1、L2菌株的发酵液对金黄色葡萄球菌的抑菌效价分别2000IU/ml、1000IU/ml;对枯草芽孢杆菌的抑菌效价分别1500IU/ml、1000IU/ml;对大肠杆菌的抑菌效价分别1500IU/ml、500IU/ml。

Five strains of Bacillus cereus （B.C） were isolated from several samples and identified the characters of the five strains then made integral morphology, and the identification is physiology and biochemistry experiments with Bacillus cereus B.C classification standards .The results show： L, was Bacillus licheniformis, L2 was Bacilli cereus, L3 was Bacillus pumilus, L4 and L5 were Bacilli cereus; Through antibiotic experiments, indicated the antibiotic charts of the five strains; single out two strains which has the most antibiotic effect ,using Joan-board diffusion method, the consequence showed that at 30°C, pH7.0, 150 r/min, constant temperature cultivate 24 hours ,the antibiotic activity of L1 and L2 were about 2000IU/ml, 1000IUml.