Center for Microbiology Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium(2); CAPTURE, Belgium(3).
Center for Microbiology Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium(2); SynBioC, Department of Green Chemistry and Technology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium.
Bioresour Technol. 2019 Oct;289:121574. doi: 10.1016/j.biortech.2019.121574. Epub 2019 May 28.
Valeric acid and its ester derivatives are chemical compounds with a high industrial interest. Here we report a new approach to produce them from crude glycerol, by combining propionic acid fermentation with chain elongation. Propionic acid was produced by Propionibacterium acidipropionici (8.49 ± 1.40 g·L). In the subsequent mixed population chain elongation, valeric acid was the dominant product (5.3 ± 0.69 g·L) of the chain elongation process. Residual glycerol negatively impacted the selectivity of mixed culture chain elongation towards valeric acid, whereas this was unaffected when Clostridium kluyveri was used as bio-catalyst. Valeric acid could be selectively isolated and upgraded to ethyl valerate by using dodecane as extractant and medium for esterification, whereas shorter-chain carboxylic acids could be recovered by using a 10 wt% solution of trioctylphosphine oxide (TOPO) in dodecane. Overall, our work shows that the combined fermentation, electrochemistry and homogeneous catalysis enables fine chemical production from side streams.
戊酸及其酯衍生物是具有高工业价值的化合物。在这里，我们报告了一种从粗甘油生产它们的新方法，即将丙酸发酵与链伸长相结合。丙酸由丙酸丙酸杆菌（Propionibacterium acidipropionici）产生（8.49±1.40g·L）。在随后的混合种群链伸长中，戊酸是链伸长过程中的主要产物（5.3±0.69g·L）。残余甘油对混合培养物链伸长对戊酸的选择性有负面影响，而当使用克氏梭菌（Clostridium kluyveri）作为生物催化剂时则不受影响。戊酸可以通过使用十二烷作为萃取剂和酯化介质选择性地分离和升级为戊酸乙酯，而较短链羧酸可以通过使用 10wt%三辛基氧化磷（TOPO）在十二烷中的溶液回收。总的来说，我们的工作表明，组合发酵、电化学和均相催化能够从副产物中生产精细化学品。
