亚损伤状态下枯草芽孢杆菌芽胞萌芽影响因素的研究

Effects of germination factors on Bacillus subtilis spores in the sub(lethal) stage

为了研究食品中营养要素对处于亚损伤状态枯草芽孢杆菌芽胞的影响,采用分批培养法,利用食品中存在的碳源、氮源、无机盐离子等分别诱导芽胞萌芽,采用正交实验研究了温度、p H、接种量、溶氧量对芽胞萌芽率的影响,分别在OD580下测定其光密度值,得到芽胞萌芽率。结果显示,麦芽糖、乳清蛋白是芽胞萌芽的最佳碳源、氮源;无机盐Mg SO4对芽胞萌芽产生显著的诱导作用。以麦芽糖(5 mg/m L),Mg SO_4(5 mg/m L),乳清蛋白(5 mg/m L)为基础培养基,芽胞的最佳生长条件为:接种量4%、p H7.0、溶氧量70 m L,37℃恒温振荡培养60 min,得芽胞萌芽率最大为15.27%。

The effect of food nutritional ingredient on Bacillus subtilis spores in the sub（lethal） stage germination was evaluated,which the impact of carbon,nitrogen,inorganic salts in food on spore germinate was conducted by batch culture method, and temperature, p H, inoculum size, oxygen content was studied by orthogonal experimental design. To quantitatively analyse the effect of these factors,the optical density of OD580 was determined to calculate germination rate. The results showed that maltose,whey protein were the best C source and N source of spore germination,respectively. Mg SO_4 had a significant induction effect on spore germination.Based on the best nutrients of maltose（5 mg/m L）,Mg SO_4（5 mg/m L）,whey protein（5 mg/m L）,optimal growth conditions for spore was that an inoculum of 4% of Bacillus subtilis spores in media with p H7.0 were cultured under 37 ℃,and the dissolved oxygen was 70 m L,constant shaking for 60 min,resulted in the maximum spore germination rate was 15.27%.