枯草芽孢杆菌MX-6的特性研究

Study on the Characteristics of Bacillus subtilis MX-6

以中国豆豉中筛选到的一株枯草芽孢杆菌MX-6为研究对象,分析其生长曲线、耐受性、抑菌特性及耐药性。枯草芽孢杆菌MX-6培养14h达到最大生物量,菌株的活性强、生长快,具有较高的温度耐受性,在100℃处理30min存活率亦可达到52.91%。枯草芽孢杆菌MX-6经人工胃液pH(1~4)处理1~4h,存活率均达到71.87%以上,结果表明菌株对胃液的耐受性较强。人工肠液和不同浓度胆盐对菌株均有一定的影响,0.1%~0.4%的胆盐对枯草芽孢杆菌MX-6的存活率影响不显著(P>0.05),存活率达到74.13%以上。枯草芽孢杆菌MX-6的发酵液对青霉、金黄色葡萄球菌和大肠杆菌均有较强的抑菌效果,而对乳酸菌无抑制作用,不具有耐药性。结果显示:该菌株的发酵速度快、耐受性强、抑菌特性明显、无耐药性,具有开发为益生菌制剂的潜能,有助于其工业化应用。

A strain of Bacillus subtilis MX-6 isolated from Chinese fermented soya beans is studied to analyze its growth curve,tolerance,bacteriostasis characteristics and drug resistance.Bacillus subtilis MX-6 reaches the maximum biomass after 14 hours'culture,and the strain has strong activity and grows fast.It has high temperature tolerance,and the survival rate can reach 52.91%after treatment for 30 min at 100℃.The survival rate of Bacillus subtilis MX-6 treated with artificial gastric juice pH(1~4)for 1~4 h is over 71.87%.The results show that the strain has strong tolerance to gastric juice.Artificial intestinal juice and different concentration of bile salt have certain effects on the strain.0.1%~0.4%bile salt has no significant effect on the survival rate of Bacillus subtilis MX-6(P>0.05),and the survival rate is over 74.13%.The fermentation broth of Bacillus subtilis MX-6 has strong bacteriostasis effect on Penicillium,Staphylococcus aureus and Escherichia coli,but has no inhibition effect on lactic acid bacteria and has no drug resistance.The results show that the strain has fast fermentation speed,strong tolerance,obvious bacteriostasis characteristics and no drug resistance.It has the potential to develop probiotics and is conducive to its industrial application.