大丽轮枝菌拮抗细菌B.subtilis LZ2-70产芽孢条件优化

 为了提高大丽轮枝菌（Verticillium dahilae Kleb.）拮抗细菌枯草芽孢杆菌 Bacillus subtilis LZ2-70菌株的芽孢形成率及芽孢数量，在摇瓶发酵基础上对影响该菌芽孢形成的主要因素进行了考察。通过单因素试验确定了最佳的碳源、氮源和无机盐等，通过正交试验研究了培养基最佳浓度和组合，以及种龄、接种量、培养液初始pH和培养时间等发酵条件。摇瓶发酵生产芽孢的最佳条件为:0.5% 麦芽糖、2% 黄豆饼粉、0.05% KH₂PO₄和0.1% MnSO₄·H₂O、培养液初始pH值8.0、种龄24 h、装瓶量30 mL/ 250 mL 、接种量10%、发酵时间48 h、培养温度为30 ℃、摇床转速为200 r·min^-1。在此优化条件下，发酵液中LZ2-70菌株的芽孢数量达到6.6×10⁹ 个·mL^-1，芽孢形成率为98.94%。

Optimization of Spore Production Conditions of Antagonistic Bacteria Bacillus subtilis LZ2-70 Against Verticillium dahliae

In order to improve the spore production rate and spore quantity of antagonistic strain Bacillus subtilis LZ2-70 against Verticillium dahliae , the main factors influencing spore production were investigated using shake-flask fermentation method.Through single factor experiment and orthogonal experiment, the optimal shaking flask fermentation condition of strain Bacillus subtilis LZ2-70 was determined as follows: media composed of 0.5% Maltose, 2% soybean meal, 0.05% KH2PO4 and 0.1% MnSO4·H2O, initial pH 8.0, culture time 24 h and bottle filling capacity 30 mL/250 mL, 10% inoculums volume, fermentation time 36 h, fermentation temperature 30℃, rotating speed 200 r·min-1.Under this optimum condition, the spore quantity of strain Bacillus subtilis LZ2-70 achieves 6.6×109·mL-1 and the spore production rate achieves 98.94%.