Your new experience awaits. Try the new design now and help us make it even better

ORIGINAL RESEARCH article

Front. Microbiol.

Sec. Microbiotechnology

Volume 16 - 2025 | doi: 10.3389/fmicb.2025.1597990

Carbon chain elongation microorganism stimulates caproate production from ethanol and acetate under applied voltage regulation

Provisionally accepted
Jing  LiJing Li1He  LiuHe Liu2Xuedong  ZhangXuedong Zhang2Hao  TanHao Tan1Xiaolong  XiongXiaolong Xiong1Weiwei  LongWeiwei Long1Xing  LuoXing Luo1*
  • 1Sichuan Academy of Agricultural Sciences, Chengdu, China
  • 2Jiangnan University, Wuxi, Jiangsu Province, China

The final, formatted version of the article will be published soon.

Carbon chain elongation has been an innovative process for the synthesis of medium-chain fatty acids (MCFAs). Among them, caproate is a vital multi-functional one. To enhance the synthesis efficiency of caproate, the growth conditions of carbon chain elongation microorganisms need to optimize to develop an ideal niche, ultimately enhancing the production of caproate. In this study, the microbial enrichment of carbon chain elongation was obtained and the optimal system of carbon chain elongation was constructed. The optimal condition for carbon chain elongation was achieved at a pH of 7.00, an ethanol/acetic acid carbon molar ratio of 4:1, and a voltage of 0.7 V. The result showed that the concentration of caproate in the optimal group increased by 83.09% in comparison to the control group. Subsequently, compared with the initial microbial community structure, the relative abundance of microorganisms changed greatly in the optimal system, including Clostridium_sensu_stricto_12, Christensenellaceae_R-7_group, Anaerofilum, Clostridium_sensu_stricto_7, and Intestinimonas. Additionally, functional prediction analysis revealed that the optimal system enhanced amino acid metabolism (alanine, aspartate, and glutamate), carbon metabolism (CoA biosynthesis), and energy metabolism by 33.66%, 30.42%, and 17.05%, respectively. Besides, both the fatty acid biosynthesis (FAB) and reverse β oxidation (RBO) pathways were enhanced in optimal system. This study elucidates a novel mechanistic insight into the efficient microbial synthesis of caproate through carbon chain elongation pathways, demonstrating how applied voltage regulation can significantly enhance the bioproduction of MCFAs from simple substrates such as ethanol and acetate. Furthermore, this work presents a sustainable and energy-efficient strategy for caproate production, reducing reliance on fossil-derived precursors.

Keywords: Carbon chain elongation, Optimal system, Caproate, metabolism pathways, microbial community

Received: 22 Mar 2025; Accepted: 28 May 2025.

Copyright: © 2025 Li, Liu, Zhang, Tan, Xiong, Long and Luo. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Xing Luo, Sichuan Academy of Agricultural Sciences, Chengdu, China

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.