米糠纤维床反应器固定化发酵产丁酸的研究

Production of Butyric Acid by Immobilized Cell Fermentation in a Rice Bran Fibrous-Bed Bioreactor

将米糠作为固定化载体,构建了一种新型的外置式纤维床反应器,应用于固定化发酵产丁酸实验。以酪丁酸梭菌为发酵菌株,进行了游离细胞和固定化细胞发酵比较。结果表明:固定化细胞分批发酵丁酸生产率为0.48 g/L/h,比游离分批发酵提高了55%。进行了重复分批发酵,8个批次的丁酸浓度平均值为21.05 g/L,可以稳定多批次运行。在发酵条件一致的情况下,进行了米糠对丁酸钠的吸附模拟实验,米糠对丁酸钠的平衡吸附量可达0.084 g/g。固定化发酵后的米糠会吸附产物丁酸钠,吸附量为0.105 g/g,这有利于将反应后的米糠直接用来生产含丁酸钠的饲料添加剂。

A novel external fibrous-bed bioreactor with rice bran as cell immobilized material for butyric acid production is established in this study. Using Clostridium tyrobutyricum as the fermentation strain,free-cell and immobilized-cell fermentation for butyric acid production are conducted. The results show that the productivity of immobilized-cell batch fermentation reaches0.48 g/L/h,which is 55% higher than that of free cells. Furthermore,21.05 g/L butyrate is achieved by immobilized cells in the repeated batch fermentation and butyrate production is stable by using this system. Finally,the simulation experiments about adsorption of sodium butyrate by rice bran are conducted,and the ratio of equilibrium adsorption is about 0.084 g/g. The sodium butyrate in the fermentation broth could be adsorbed by the rice bran and the ratio of adsorption is 0.105 g/g. The rice bran in this study can be directly used as feed additive.