Acclimation of anaerobic fermentation microbiome with acetate and ethanol for chain elongation and the biochemical response

Lin Li; Chang Liu; Linji Xu; Huichuan Zhuang; Junguo He; Qiang He; Jie Zhang

doi:10.1016/j.chemosphere.2023.138083

Acclimation of anaerobic fermentation microbiome with acetate and ethanol for chain elongation and the biochemical response

Chemosphere. 2023 Apr:320:138083. doi: 10.1016/j.chemosphere.2023.138083. Epub 2023 Feb 6.

Authors

Lin Li¹, Chang Liu², Linji Xu³, Huichuan Zhuang⁴, Junguo He⁵, Qiang He², Jie Zhang⁶

Affiliations

¹ College of Environment and Ecology, Chongqing University, Chongqing 400044, China; State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
² College of Environment and Ecology, Chongqing University, Chongqing 400044, China.
³ College of Environment and Ecology, Chongqing University, Chongqing 400044, China. Electronic address: lin_ji_good@126.com.
⁴ Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
⁵ State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; School of Civil Engineering, Guangzhou University, Guangzhou 510006, China. Electronic address: hejunguohit@163.com.
⁶ State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.

PMID: 36754309
DOI: 10.1016/j.chemosphere.2023.138083

Abstract

Medium chain fatty acids (MCFAs) production is a promising method for resource recovery from organic wastes. In this study, the microbial community structure shift along the long-term acclimation experiment and the concomitant effect of H₂ level on chain elongation performance was investigated. Chain elongation microbiome could be rapidly acclimated from traditional anaerobic fermentation consortia. Genera Caproiciproducens, Clostridium sensu stricto 12, Rummeliibacillus and Oscillibacter was found to be dominant during the operation. The H₂ was accumulated in the headspace by increasing the ethanol input, which inhibited oxidation of caproate and butyrate immediately, while its inhibition effect on chain elongation was delayed. H₂ level in the headspace was positively correlated to the MCFAs production related bacteria. However, too much H₂ accumulated might be suppressive for MCFAs production in the long term. It might result from the thermodynamic barrier for discarding excess reducing equivalents under high H₂ level, which further gave rise to ethanol accumulation in this system.

Keywords: Acclimation; Caproate; Chain elongation; Medium-chain fatty acids; Microbial community.

MeSH terms

Acetates
Anaerobiosis
Bioreactors
Ethanol*
Fatty Acids
Fermentation
Microbiota*

Substances

Ethanol
Fatty Acids
Acetates