纤维床反应器固定化发酵生产丁酸的中试放大

Production of butyric acid by immobilized cells in a fibrous-bed bioreactor of pilot-scale

以酪丁酸梭菌为出发菌株,葡萄糖为底物进行批次和补料发酵生产丁酸。基于5 L通用发酵罐和纤维床生物反应器(FBB)发酵生产丁酸的研究基础,在5 000 L体系纤维床上进行丁酸发酵的中试规模放大。5L通用发酵罐发酵体系中,固定化批次发酵的平均糖酸转化率为0.47 g/g,丁酸生产强度为0.82 g/(L·h),分别比游离发酵提高了31%和134%。补料发酵中,丁酸浓度达52.8 g/L,比游离补料发酵提高了46%。在纤维床中试规模放大研究中,批次发酵的平均糖酸转化率为0.48 g/g,丁酸生产强度为0.63 g/(L·h),比游离发酵分别提高了37%和67%。补料发酵的丁酸浓度为51.63 g/L,与游离发酵相比提高了40%。结果表明,与实验室规模相比,纤维床反应器能够放大到1 000倍,能够保持较高的丁酸发酵水平和生产效率。

In this paper, efficient production of butyric acid from glucose by Clostridum tyrobutyricum was performed with batch and fed-batch modes. Based on the results of 5-L fermentor＇ s experiments, the fermentation process was successfully scaled up in a 5000-L fermentor. In 5-L fermentor batch modes, butyrate yield and productivity was reached to 0.47 g/g and 0.82 g/L·h respectively, which was improved by 31% and 134% compared with fermentations of free cells. In the fed-batch fermentation, the final concentration of butyric acid was 52.8 g/L, increased by 46% compared to free-cell fermentation. From up-scaled fed-batch production of butyrate in the pilot plant, butyrate yield, productivity and butyrate concentration with immobilized-cells reached 0.47 g/g, 0.63 g/（ L·h） and 51.63 g/L, which were improved by 37% , 67% and 40% respectively. Results showed that compared with the laboratory scale, the fibrous bed reactor could maintain a higher level of butyric acid fermentation and the production efficiency when zoom up to 1000 times. The present work provides a powerful alternative to produce butyric acid as a bulk chemical in pilot scale.