两株芽孢杆菌混菌发酵产芽孢条件的优化

为了探索地衣芽孢杆菌（Baclicus lincheniformis）DY-1和胶冻样芽孢杆菌（Bacillus mucilaginosus）XK混菌发酵产芽孢的最佳条件，该研究采用单因素试验和正交试验进行了优化；利用Eppendorf 7.5 L发酵罐在最佳条件下进行了混菌发酵产芽孢试验。结果表明，混菌发酵产芽孢的最佳发酵条件为：胶冻样芽孢杆菌XK和地衣芽孢杆菌DY-1种子液的接种比例为4∶1（V/V），培养温度37 ℃，培养时间60 h，pH 8.0。在此条件下，进行Eppendorf 7.5 L发酵罐混菌发酵试验，其芽孢数可高达1.1×1011 CFU/mL，高于摇瓶发酵所产芽孢数（2.0×1010 CFU/mL）。

Optimization of spore-producing conditions of two Bacillus spp. mixed fermentation

In order to explore the optimum spore-producing conditions of Bacillus licheniformis DY-1 and Bacillus mucilaginosus XK mixed fermentation, the study was optimized by single factor and orthogonal experiments. Eppendorf 7.5 L fermentor was used to produce spores under the optimum conditions. The results showed that the optimum spore-producing conditions of two Bacillus spp. mixed fermentation were as follows: the seed solution inoculation proportion of B. mucilaginosus XK 4∶1 and B. licheniformis DY-1 (V/V), culture temperature 37 ℃, culture time 60 h and pH 8.0. Under the conditions, the spore count was up to 1.1×1011 CFU/ml in Eppendorf 7.5 L fermentor, which was higher than that of shaking flask fermentation (2.0×1010 CFU/ml).