响应面法优化油茶炭疽病拮抗细菌R6发酵条件

Optimization of fermentation conditions of antagonistic bacterium R6 in the Camellia by response surface methodology

[目的]为了获得拮抗细菌R6的最佳发酵条件,提高其对油茶炭疽病菌的抑菌活性。[方法]采用响应面分析法对拮抗细菌R6发酵条件进行了优化。首先通过Plackett-Burman试验筛选出对菌体浓度影响较大的3个重要因素即初始p H、摇床转速、培养温度,最后应用响应面法进行分析。[结果]菌株R6的最佳发酵条件为:初始p H8.10、培养温度30.30℃、摇床转速171.00r/min、接种量5%、培养时间24h,此时,发酵液的OD600为1.915,与模型的预测值基本相符。优化后菌体浓度和对油茶炭疽病菌的抑菌率较优化前分别提高了9.56%和12.24%。[结论]响应面法优化得到的R6的发酵条件参数准确,该模型可以用于R6菌株发酵条件的优化。

[Objective]Plackett-Burman design and response surface methodology were used to optimize the fermentation conditions of antagonistic bacterium R6 and improve the inhibition rate of Colletotrichum gloeosporioides. [Methods]Response surface methodology was used to optimize the fermentation conditions of antagonistic bacterium R6. Three of the most significant influence factors were screened by the method of Plackett-Burman design as initial p H,rotating speed and cultural trmperature. After response surface analysis was applied to establish the regression equation model. [Results]The optimal fermentation conditions were initial p H value 8. 10,30. 30℃ of culture temperature,171. 00 r/min of rotating speed,5% of inoculation,and 24 h of culture time. Under the optimum conditions,the OD600 of fementation was 1. 915 and the experimental values agreed with the predicted values. The cell concentration and bacteriostatic rate of Colletotrichum gloeosporioides were increased by 9. 56% and 12. 24% respectively compare to that before optimization. [Conclusion]The optimum conditions of R6 from response surface methodology were validity,the predicted model was reliable and available for the optimization of R6 fermentation conditions.