MESSAI.iO

AI summary

70% confidence

Methanogenic biocathodes exhibit superior performance with stainless steel cathodes, attributed to higher EPS secretion and lower ROS levels, which protect cells from harsh metabolic conditions.

Generated by MESSAI extraction pipeline · review against source PDF

Generic MECRepresentative model
Click to animate flow
loading 3D model…

Representative MEC — matched on the paper’s system type only, not its reactor or geometry.

Extraction

Reported parameters

106 extracted values

View extracted values

Open in lab for full controls, parameter editing, and template overlays.

Open in lab →

What they did

System
MEC
Substrate
pure compound

What worked

No outcome metrics extracted yet.

Abstract

Abstract The microbial electrolysis cell assisted anaerobic digestion (MEC-AD) holds great promises over conventional anaerobic digestion. This article reports an experimental investigation of extracellular polymeric substances (EPS), reactive oxygen species (ROS), and the expression of genes associated with extracellular electron transfer (EET) in methanogenic biocathodes. The MEC-AD systems were examined using two cathode materials: carbon fibers and stainless-steel mesh. A higher abundance of hydrogenotrophic Methanobacterium sp. and homoacetogenic Acetobacterium sp. appeared to play a major role in superior methanogenesis from stainless steel biocathode than carbon fibers. Moreover, the higher secretion of EPS accompanied by the lower ROS level in stainless steel biocathode indicated that higher EPS perhaps protected cells from harsh metabolic conditions (possibly unfavorable local pH) induced by faster catalysis of hydrogen evolution reaction. In contrast, EET-associated gene expression patterns were comparable in both biocathodes. Thus, these results indicated hydrogenotrophic methanogenesis is the key mechanism, while cathodic EET has a trivial role in distinguishing performances between two cathode electrodes. These results provide new insights into the efficient methanogenic biocathode development.

Key findings

  • Higher abundance of hydrogenotrophic Methanobacterium sp. and homoacetogenic Acetobacterium sp. in stainless steel biocathode
  • EPS secretion is higher in stainless steel biocathode, possibly protecting cells from local pH fluctuations
  • EET-associated gene expression patterns are comparable in both biocathodes

Keywords

Microbial electrolysis cellMethanogenesisExtracellular polymeric substanceExtracellularReactive oxygen speciesElectron transfer

Identifiers

DOI
10.1101/2020.11.12.380824
Journal
bioRxiv (Cold Spring Harbor Laboratory)
Year
2020