Liu Qingguo, Liu Jing, Yan Alan, Sun Wenjun, Liang Caice, Chen Tianpeng, Wen Qingshi, Chen Yanjun, Ying Hanjie, Chen Yong
College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China; Nanjing Hi-Tech Biological Technology Research Institute Co. Ltd., Nanjing, China.
College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China.
J Biotechnol. 2025 Sep;405:254-262. doi: 10.1016/j.jbiotec.2025.06.003. Epub 2025 Jun 7.
This study evaluated the feasibility of ethanol production from corn in a surface immobilized bioreactor. The mass transfer of 50 L immobilized bioreactor was analyzed based on computational fluid dynamics (CFD) simulation. Compared to the traditional stirred fermenter, the surface immobilized fermenter system exhibited a relatively weak liquid velocity, but its flow field distribution was relatively uniform, which ensured an ideal interaction environment between cells and substrates. The difference of fermentation indexes between the two fermentation methods was then verified by ethanol fermentation using corn hydrolysate. It was found that the ethanol productivity (P) of immobilized cells was increased by 20.59 %, while the amount of corn consumed for one ton of ethanol was decreased by 5.90 %. To further enhance industrial application, the semi-continuous fermentation was adopted, the P and ethanol yield were increased by 30.88 % and 3.06 percentage points, respectively, compared to free-cell fermentation (FCF). This work demonstrated that the mass transfer issues associated with traditional immobilized-cell fermentation (ICF), such as embedding and chemical crosslinking, were resolved through bioreactor design and process optimization. Meanwhile, the surface immobilization technology showcased special advantages, including a broad spectrum of raw materials and strong process stability, indicating great industrial application potential in ethanol production.
本研究评估了在表面固定化生物反应器中用玉米生产乙醇的可行性。基于计算流体动力学（CFD）模拟分析了50 L固定化生物反应器的传质情况。与传统搅拌发酵罐相比，表面固定化发酵罐系统的液体速度相对较弱，但其流场分布相对均匀，这确保了细胞与底物之间理想的相互作用环境。然后通过使用玉米水解产物进行乙醇发酵来验证两种发酵方法之间发酵指标的差异。结果发现，固定化细胞的乙醇生产率（P）提高了20.59%，而生产一吨乙醇所消耗的玉米量减少了5.90%。为了进一步提高工业应用，采用了半连续发酵，与游离细胞发酵（FCF）相比，P和乙醇产率分别提高了30.88%和3.06个百分点。这项工作表明，通过生物反应器设计和工艺优化解决了与传统固定化细胞发酵（ICF）相关的传质问题，如包埋和化学交联。同时，表面固定化技术展现出特殊优势，包括原料范围广和工艺稳定性强，表明在乙醇生产中具有巨大的工业应用潜力。
