【摘要】 为了对贝莱斯芽孢杆菌(Bacillus velezensis)CY30的发酵培养基进行优化以提高芽孢产量,应用Plackett-Burman设计法对影响贝莱斯芽孢杆菌CY30芽孢形成的关键因子进行筛选,通过最陡爬坡路径法确定主要影响因素的响应中心点,并进一步采用中心组合设计和响应面分析法确定最优培养基。结果表明,该菌株芽孢产量的关键影响因素为甘薯粉和酵母膏的浓度。通过响应面分析法的拟合和推算得到,甘薯粉和酵母膏浓度分别为37.35 g/L和15.29 g/L时,模型预测发酵最佳产量为91.2亿CFU/mL,验证值为97.5亿CFU/mL,预测值与验证值之间吻合较好,比优化前实际产量(63.8亿CFU/mL)提高了53%。更多还原

【Abstract】 To optimize the fermentation medium of Bacillus velezensis CY30 for enhancing the spore counts in the fermentation broth, the key factors among the media components were investigated by using Plackett-Burman(PB) design. The central axises of these factors were determined by using steepest-ascent method. The optimized medium for Bacillus velezensis CY30 was determined by central combination design and response surface method. The results demonstrated that the key factors influcening the spore counts in fermentation broth were sweet potato powder and yeast extract. The optimized medium was obtained through response surface analysis was 37.52 g/L of sweet potato powder, 15.29 g/L of yeast extract. The estimated maximum spore counts was 9.12 billion CFU/mL, while the real spore counts was 9.75 billion CFU/mL in shake-flask fermentation. The spore counts of the fermentation broth with optimized medium was 53% higher than that before the optimization(6.38 billion CFU/mL).更多还原