Hernandez Paula Andrea, Zhou Miaomiao, Vassilev Igor, Freguia Stefano, Zhang Yang, Keller Jürg, Ledezma Pablo, Virdis Bernardino
Advanced Water Management Centre, The University of Queensland, Brisbane, Queensland 4072, Australia.
Shandong University, 72 Binhai Road, Jimo District, Qingdao 266237, PR China.
ACS Omega. 2021 Mar 12;6(11):7841-7850. doi: 10.1021/acsomega.1c00397. eCollection 2021 Mar 23.
Carboxylic acids obtained the microbial electrochemical conversion of waste gases containing carbon dioxide (, microbial electrosynthesis) can be used of nonrenewable building-block chemicals in the manufacture of a variety of products. When targeting valuable medium-chain carboxylic acids such as caproic acid, electricity-driven fermentations can be limited by the accumulation of fermentation products in the culturing media, often resulting in low volumetric productivities and titers due to direct toxicity or inhibition of the biocatalyst. In this study, we tested the effectiveness of a simple electrodialysis system in upconcentrating carboxylic acids from a model solution mimicking the effluent of a microbial electrochemical system producing short- and medium-chain carboxylic acids. Under batch extraction conditions, the electrodialysis scheme enabled the recovery of 60% (mol mol) of the total carboxylic acids present in the model fermentation broth. The particular arrangement of conventional monopolar ion exchange membranes and hydraulic recirculation loops allowed the progressive acidification of the extraction solution, enabling phase separation of caproic acid as an immiscible oil with 76% purity.
通过微生物电化学转化含二氧化碳废气获得的羧酸（即微生物电合成）可用于制造各种产品中的不可再生基础化学品。当目标是己酸等有价值的中链羧酸时，电驱动发酵可能会受到培养基中发酵产物积累的限制，由于生物催化剂的直接毒性或抑制作用，常常导致低体积生产率和低滴度。在本研究中，我们测试了一种简单的电渗析系统从模拟产生短链和中链羧酸的微生物电化学系统流出物的模型溶液中富集羧酸的有效性。在分批萃取条件下，电渗析方案能够回收模型发酵液中60%（摩尔/摩尔）的总羧酸。传统单极离子交换膜和水力循环回路的特殊布置使得萃取溶液能够逐步酸化，从而实现纯度为76%的己酸作为不混溶油相的相分离。
