1株藏猪源枯草芽孢杆菌BY-2的益生特性分析

Probiotic properties of a Bacillus subtilis from Tibetan pigs

评价了来自藏猪盲肠的1株生长快,能高效降解纤维素的细菌枯草芽孢杆菌（Bacillus subtilis）BY-2的益生特性。结果表明,BY-2能够耐受高温,在65～85℃条件下培养20min,其存活率均达到90%及以上,均显著高于BY-2在100℃条件下的存活率（59.1%）（P〈0.05）。BY-2在人工胃液中培养,随着pH值的升高存活率呈上升趋势,在不同pH1～4下培养长达4h时,存活率为73.78%～83.61%,其中pH1条件下BY-2的存活率显著低于pH2～4的存活率（P〈0.05）。人工肠液和不同浓度胆盐对BY-2的存活率均有影响,但胆盐浓度对BY-2存活率的影响差异不显著（P〉0.05）,当在不同胆盐浓度的人工肠液中培养4h,BY-2的存活率均在75%以上。此外,BY-2的提取液对大肠杆菌、沙门菌和金黄色葡萄球菌均有强的抑制能力。由试验结果看,BY-2表现出强的抗逆特性及抗菌特性,具有作为猪源益生菌微生态制剂开发的潜力。

The experiment evaluated the probiotic properties of the Bacillus subtilis BY-2 which grow fast and degrade cellulose efficiently from Tibetan pigs cecum.The results showed that BY-2could tolerate high temperature.The survival rate of BY-2reached above 90% when cultured at 65-85℃for 20 min,which was significantly higher than that（59.1%）of 100℃（P〈0.05）.When cultured in artificial gastric fluid,there was an upward trend with the increase of pH value.The survival rate was 73.78%-83.61% when cultured under pH1-4for 4hours.While the survival rate of BY-2under the condition of pH1 was significantly lower than that under pH2-4（P〈0.05）.Artificial intestinal fluid of different concentration of bile salt also affected the survival rate of BY-2,while the impact of bile salt on the survival rate of BY-2was not significant（P〉0.05）.The survival rate of BY-2was more than 75% when cultured under artificial intestinal fluid with different concentration of bile salt for 4h.Furthermore,the extract of BY-2had a potent inhibitory ability to Escherichia,Salmonellaand Staphylococcus.From the results of the experiment,it was found that BY-2had a strong resilience characteristics and antibacterial properties,which has a potential of probiotics for pigs.