Clostridium butyricum, an anaerobic spore-forming bacillus, is a common human and animal gut commensal bacterium. Spore is an important structure for C. butyricum to tolerate environmental stress. However, it is not easy to form in common fermentation process of C. butyricum. In this study, the parameters for optimizing the spore formation of C. butyricum NN-2 were defined. The results showed that the pH value was a crucial factor that significantly affected the spore formation of C. butyricum NN-2. Down-regulation steps of pH value from 6.5 to 5.5 over time during the cultural process significantly (p < 0.05) promoted spore formation of C. butyricum NN-2, allowing for the sporulation rate of > 90%. In addition, the duration of pH regulation also had significant effects on the spore formation of C. butyricum NN-2. The results revealed a highly effective strategy for enhancing the spore production of C. butyricum.

中文翻译：

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优化pH条件提高丁酸梭菌NN-2发酵过程产孢量

酪酸梭菌是一种厌氧产芽孢杆菌，是一种常见的人和动物肠道共生菌。孢子是 C. butyricum 耐受环境压力的重要结构。但在普通丁酸梭菌发酵过程中不易形成。在本研究中，定义了优化 C. butyricum NN-2 孢子形成的参数。结果表明，pH值是显着影响C. butyricum NN-2孢子形成的关键因素。在培养过程中，随着时间的推移，pH 值从 6.5 到 5.5 的下调步骤显着 (p < 0.05) 促进了 C. butyricum NN-2 的孢子形成，使孢子形成率 > 90%。此外，pH调节的持续时间对C. butyricum NN-2的孢子形成也有显着影响。