Laboratory of Optimization, Design, and Advanced Control - Fermentation Division (LOPCA-Ferm), School of Chemical Engineering, University of Campinas (UNICAMP), Campinas, SP, Brazil.
Bioprocess and Metabolic Engineering Laboratory (LEMeB), School of Food Engineering, University of Campinas (UNICAMP), Campinas, SP, Brazil.
Bioresour Technol. 2022 Jan;344(Pt B):126313. doi: 10.1016/j.biortech.2021.126313. Epub 2021 Nov 16.
The Isopropanol-Butanol-Ethanol productivity by solventogenic clostridia can increase when cells are immobilized on low-cost, renewable fibrous materials; however, butanol inhibition imposes the need for dilute sugar solutions (less than40 g/L). To alleviate this problem, the in-situ vacuum product recovery technique was applied to recover IBE in repeated-batch cultivation of Clostridium beijerinckii DSM 6423 immobilized on sugarcane bagasse. Five repeated batch cycles were conducted in a 7-L bioreactor containing P2 medium (∼60 g/L glucose) and bagasse packed in 3D-printed concentric annular baskets. In three cycles, glucose was consumed by 86% on average, the IBE productivity was 0.35 g/L∙h or 30% and 17% higher relative to free- and immobilized (without vacuum)-cell cultures. Notably, the product stream contained 45 g/L IBE. However, the fermentation was unsatisfactory in two cycles. Finally, by inserting a fibrous bed with hollow annuli in a vacuum fermentation, this work introduces the concept of an internal-loop boiling-driven fibrous-bed bioreactor.
溶剂梭菌的异丙醇-丁醇-乙醇生产力可以通过将细胞固定在低成本、可再生的纤维材料上而提高；然而，丁醇的抑制作用需要稀糖溶液（小于 40g/L）。为了缓解这个问题，采用原位真空产物回收技术，在固定化于甘蔗渣的凝结芽孢杆菌 DSM 6423 的重复分批培养中回收 IBE。在一个装有 P2 培养基（约 60g/L 葡萄糖）和 3D 打印同心环形篮中包装的甘蔗渣的 7-L 生物反应器中进行了五次重复批处理循环。在三个循环中，葡萄糖的平均消耗率为 86%，IBE 的生产力为 0.35g/L·h，比游离细胞和固定化（无真空）细胞培养分别提高了 30%和 17%。值得注意的是，产物流中含有 45g/L 的 IBE。然而，在两个循环中，发酵效果不佳。最后，通过在真空发酵中插入具有中空环的纤维床，这项工作引入了内部环路沸腾驱动纤维床生物反应器的概念。
