短小芽孢杆菌(Bacillus pumilus)X93胞外产物对病原弧菌抑制效果的研究

采用平板扩散法对从健康大黄鱼肠道中分离筛选到的对病原弧菌有抑制作用的短小芽孢杆菌(Bacillus pumi-lus)X93胞外产物(Extracellular products,ECP)作用的环境影响因子进行了研究。结果显示,菌株X93胞外产物的抑菌活性强弱随着培养时间的不同而不同,胞外产物对pH条件有一定的耐受性,对热敏感,不耐高温,过高的NaCl能使其抑菌活性降低,蛋白酶K和不同浓度的FeCl3均对其抑菌活性产生影响,其胞外产物发挥最大抑菌作用的最适培养时间、温度、pH、盐度分别为48 h、28℃、pH 7和0.5%。

Inhibition of extracellular products of Bacillus pumilus X93 on pathogenic vibrio

The extracellular products （ECPs） of Bcuillus pumilus X93 were isolated from gastrointestinal tract of healthy cultured large yellow croaker （ Pseudosciaena crocea） , and the environmental factors on antibacterial activity of ECPs to two pathogenic vibfios were tested by flat diffusion method. The results show that the antibacterial activity varies with the culture time and ECPs not only have a certain tolerance to pH but also are sensitive to heat. Higher concentration of NaCl can reduce the antibacterial activity, and proteinase K and different concentrations of FeCl3 all have impacts on the antibacterial activity. The inhibition of the ECPs of strain X93 to two pathogenic vibrios is maximized when the optimal time, temperature, the pH, and salinity, are 48 h, 28 ℃, pH 7 and 0.5% respectively.