益生酪酸菌的固态培养

以活菌数为考察指标，研究酪酸菌在3种不同固态基质(豆粕、麸皮、玉米粉)中的生长情况。结果显示：豆粕作为基质时酪酸菌生长最佳，最高活菌数可达47×106CFU/g，麸皮次之，达39×106CFU/g，玉米粉最差，仅为34×106CFU/g。在此基础上，采用响应面法对酪酸菌固态发酵的培养基及发酵工艺进行优化。首先通过Plackett-Burman试验对酪酸菌培养基成分进行筛选，从10个因素中筛选到了4个主要影响因素，即硫酸铵、麦芽糖、硫酸镁和含水量。然后采用Box-Behnken试验设计得出硫酸铵、麦芽糖、硫酸镁的添加量分别为1.5%、0.8%、0.02%，含水量为55%时培养效果最佳，酪酸菌活菌数最高可达到约76×106CFU/g。同样采用Box-Behnken试验设计对影响酪酸菌固体发酵的工艺条件进行优化，当发酵时间为24h、温度30℃、接种量14mL/100g时，酪酸菌培养效果最佳，活菌数达到约11×107CFU/g。

Solid-state Cultivation of Clostridium butyricum

Response surface methodology (RSM) was used to explore medium composition and solid-state fermentation conditions for Clostridium butyricum. The amount of viable cells was used as the evaluation index. Four factors including (NH4)2SO4, MgSO4, maltose and water content as the major affecting factors of medium composition were screened from 10 factors by Plackett-Burman design. The results showed that the maximum number of viable cells of Clostridium butyricum could reach up to 76×106 CFU/g when the medium was composed of 1.5% (NH4)2SO4, 0.02% MgSO4, 0.8% maltose and 55% water content. Similarly, the fermentation conditions of Clostridium butyricum were optimized by Box-Behnken design combined with RSM. Fermentation time of 24 h, fermentation temperature of 30 ℃ and inoculation amount of 14 mL/100 g were optimum. Under these conditions, the maximum number of viable cells could reach up to 11×107 CFU/g.