基于MTT比色和响应面法优化侧孢短芽孢杆菌最大活菌数培养条件

Optimization of culture conditions for maximum viablecount of Brevibacillus laterosporus based on MTTcolorimetry and response surface methodology

目的:探索获得侧孢短芽孢杆菌(Brevibacillus laterosporus)最大活菌数的最佳培养基成分及培养条件。方法:在建立MTT比色法与平板计数法的相关回归方程基础上,对获得最大活菌数的侧孢短芽孢杆菌最适培养基成分(碳源、氮源、无机盐)和培养条件(初始pH、温度、接种量、磷酸二氢钾)进行优化。结果:MTT比色法与平板计数法对活菌数测定结果表现出显著的线性关联(R^(2)>0.999);麦芽糖、氯化钙、初始pH、磷酸二氢钾为显著影响因子,最佳发酵条件为麦芽糖8.75 g/L,氯化钙0.17 g/L,初始pH 7.07、磷酸二氢钾3.73 g/L,此条件下活菌数为8.12×10^(8)CFU/mL,与理论活菌数(8.25×10^(8)CFU/mL)无显著差异。结论:基于MTT比色和响应面法优化侧孢短芽孢杆菌最大活菌数培养条件,优化后的活菌数较优化前提高了3.02倍。

Objective:This study aimed to explore the optimal medium composition and culture conditions for obtaining the maximum viable count of Brevibacillus laterosporus.Methods:Based on establishing the correlation regression equation between the MTT colorimetric method and plate counting method,the optimal medium composition(carbon source,nitrogen source,inorganic salt)and fermentation conditions(initial pH,temperature,inoculation amount,KH 2 PO 4)for obtaining the maximum viable count of B.laterosporus were optimized.Results:A significant linear correlation for viable count determination between MTT colorimetry and plate counting(R^(2)>0.999)was found;Maltose,CaCl 2,initial pH and KH_(2)PO_(4)were the significant factors.The optimal fermentation condition was 8.75 g/L maltose,0.17 g/L CaCl_(2),7.07 initial pH and 3.73 g/L KH_(2)PO_(4).Under the control of these conditions,the number of viable counts was 8.12×10^(8)CFU/mL.However,no significant difference from the theoretical number(8.25×10^(8)CFU/mL)was found.Conclusion:Based on MTT colorimetry and response surface methodology,the culture conditions for the maximum viable count of B.laterosporus were optimized and the number of viable counts was higher than before optimization increased by 3.02 times.