兰花炭疽病拮抗细菌Bacillus megaterium1-12菌株的产芽孢条件优化

为了提高兰花炭疽病拮抗菌巨大芽孢杆菌(Bacillus megaterium)1-12菌株的芽孢形成率及芽孢数量,在摇瓶发酵基础上对芽孢形成的主要影响因素进行了考察.通过单因素实验和正交实验对1-12菌株产芽孢条件进行了分析,确定了摇瓶发酵最佳条件:培养基组成(质量分数)为玉米粉1%,大豆蛋白胨1%,CaCl2.2H2O 0.1%,MnSO4.H2O 0.05%;培养液初始pH 6.0;培养条件为种龄20 h,装瓶量30 mL/250 mL,接种量8%,温度30℃,摇瓶转速200 r/min.在此条件下,B.megaterium1-12菌株发酵液中的芽孢数量为1.92×109个mL-1,芽孢形成率达到了95%.

To Optimize Spore Formation Conditions of Antagonistic Strain 1-12 of Bacillus megaterium Against Colletoichum gloeosporioides

In order to improve the spore formation rate and spore quantity of antagonistic strain 1-12 of Bacillus megaterium against Colletoichum gloeosporioides,the main factors influencing spore formation were investigated using shake-flask fermentation method.Through single factor experiment and orthogonal experiment,the optimal shaking flask fermentation conditions were determined as follow: medium composed(mass fraction) of 1% corn flour,1% soybean peptone,0.1%CaCl2·2H2O,0.05% MnSO4·H2O.Initial pH 6.0,incubation time 20 h and flask coutent 30 mL / 250 mL,8% inoculum size,fermentation temperature 30 ℃,rotating speed 200 r/min.Under this optimum conditions,1.92×109 mL-1 were obtained, and the spore formation rate achieved 95%.