关键词: 萎缩芽孢杆菌, 响应面分析, 培养基优化

Abstract:

To increase the spore production of Bacillus atrophaeus BsR05, a response surface method was applied to optimize the technological conditions of BsR05 fermentation medium. Corn flour, (NH4)2SO4 and MgSO4·7H2O were selected as the major factors affecting sporulation by means of PlackettBurman design. The method of steepest ascent path was adopted to determine the response center and the optimal concentration range of these 3 factors. Finally, the regression relationship between the main medium composition and the spore yield was established by BoxBehnken design. The optimal formula for the fermentation medium was determined as follow：glucose 5 g/L，corn flour 15.9 g/L, soybean meal 40 g/L, K2HPO4 3.0 g/L, KH2PO4 1.0 g/L, (NH4)2SO4 2.1 g/L, MgSO4·7H2O 0.40 g/L and MnSO4 0.020 g/L. After repeated experiments, it was verified that the average spore content was basically consistent with the predicted spore content, and the concentration of the spore was increased from 4.73×109 CFU/mL to 6.02×109 CFU/mL after the optimization.

Key words: Bacillus atrophaeus, eesponse surface methodology, medium optimization