混合碳源发酵对纳豆芽孢杆菌生产甲萘醌-7的影响

Effects of mixed carbon sources fermentation on the production of menaquinone-7 by Bacillus natto

为了提高纳豆芽孢杆菌发酵生产甲萘醌-7的能力,以葡萄糖和甘油作为碳源进行深入研究。结果表明,葡萄糖作为碳源时有利于维持营养体形态,甘油作为碳源时有利于甲萘醌-7合成。结合了2种碳源的优点,采用葡萄糖/甘油混合碳源发酵策略。当葡萄糖与甘油混合质量比例为75∶25时,芽孢形成率比以甘油为单一碳源时下降了61.71%,且发酵产甲萘醌-7水平比以葡萄糖和甘油为单一碳源分别提高了34.61%和23.87%。该方法弥补了菌体易形成休眠体芽孢和甲萘醌-7产量低等问题,在甲萘醌-7工业生产上具有重要价值。

In order to improve the production efficiency of menaquinone-7 by Bacillus natto, further research was conducted using glucose and glycerol as carbon sources. Results showed that glucose as carbon source was conducive to maintain vegetative bacteria, while glycerol as carbon source was beneficial for menaquinone-7 synthesis. Combined with the advantages of two kinds of carbon sources, the strategy of glucose/glycerol mixed carbon sources was adopted for fermentation. When the mixture ratio of glucose to glycerol was 75：25 （w/w） , the sporulation ratio was decreased by 61.71% compared to that of glycerol as a single carbon source, and menaquinone-7 yield was respectively in- creased 34.61% and 23.87% compared to the process using glucose or glycerol as single carbon source. This strategy overcame the problem of easy sporulation and low menaquinone-7 yield, which provides significant value on menaqui- none-7 industrial production.