Elevated caproic acid production from one-stage anaerobic fermentation of organic waste and its selective recovery by electro-membrane process

• Published in: Bioresource technology 2024-05, Vol.399, p.130647-130647, Article 130647
• Main Authors: Zhao, Wenyan, Jiang, Heqing, Dong, Wenjian, Liang, Qiaochu, Yan, Binghua, Zhang, Yang
• Format: Article
• Language: English
• Subjects: Acidogenic fermentation; Bipolar membrane; Caproic acid; Chain elongation; Electrodialysis
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2024.130647

[Display omitted] •Constructed microbial consortia-based strategy enhanced caproic acid production.•Clostridium sensu stricto 1 and Caproiciproducers were key genera.•Lactate platform could contribute to product upgrading in acidogenic fermentation.•EDBM enabled phase separation of caproic acid with a purity of 82.58%. A constructed microbial consortia-based strategy to enhance caproic acid production from one-stage mixed-fermentation of glucose was developed, which incubated with acidogens (Clostridium sensu stricto 1, 11 dominated) and chain elongators (including Clostridium sensu stricto 12, Sporanaerobacter, and Caproiciproducens) acclimated from anaerobic sludge. Significant product upgrading toward caproic acid (8.31 g‧L−1) and improved substrate degradation was achieved, which can be greatly attributed to the lactic acid platform. Whereas, a small amount of caproic acid was observed in the control incubating with acidogens, with an average concentration of 2.09 g‧L−1. The strategy accelerated the shape and cooperation of the specific microbial community dominated by Clostridium sensu stricto and Caproiciproducens, which thereby contributed to caproic acid production via the fatty acid biosynthesis pathway. Moreover, the tailored electrodialysis with bipolar membrane enabled progressive up-concentration and acidification, allowing selective separation of caproic acid as an immiscible product with a purity of 82.58 % from the mixture.