Effect of anode material and dispersal limitation on the performance and biofilm community in microbial electrolysis cells
Journal article, 2023

In a microbial electrolysis cell (MEC), the oxidization of organic compounds is facilitated by an electrogenic biofilm on the anode surface. The biofilm community composition determines the function of the system. Both deterministic and stochastic factors affect the community, but the relative importance of different factors is poorly understood. Anode material is a deterministic factor as materials with different properties may select for different microorganisms. Ecological drift is a stochastic factor, which is amplified by dispersal limitation between communities. Here, we compared the effects of three anode materials (graphene, carbon cloth, and nickel) with the effect of dispersal limitation on the function and biofilm community assembly. Twelve MECs were operated for 56 days in four hydraulically connected loops and shotgun metagenomic sequencing was used to analyse the microbial community composition on the anode surfaces at the end of the experiment. The anode material was the most important factor affecting the performance of the MECs, explaining 54–80 % of the variance observed in peak current density, total electric charge generation, and start-up lag time, while dispersal limitation explained 10–16 % of the variance. Carbon cloth anodes had the highest current generation and shortest lag time. However, dispersal limitation was the most important factor affecting microbial community structure, explaining 61–98 % of the variance in community diversity, evenness, and the relative abundance of the most abundant taxa, while anode material explained 0–20 % of the variance. The biofilms contained nine Desulfobacterota metagenome-assembled genomes (MAGs), which made up 64–89 % of the communities and were likely responsible for electricity generation in the MECs. Different MAGs dominated in different MECs. Particularly two different genotypes related to Geobacter benzoatilyticus competed for dominance on the anodes and reached relative abundances up to 83 %. The winning genotype was the same in all MECs that were hydraulically connected irrespective of anode material used.

Bioelectrochemical system

Bioanode

Metagenomics

Microbial community assembly

Graphene

Author

Marie Abadikhah

Chalmers, Architecture and Civil Engineering, Water Environment Technology

Ming Liu

Beijing University of Technology

Frank Persson

Chalmers, Architecture and Civil Engineering, Water Environment Technology

Britt-Marie Wilen

Chalmers, Architecture and Civil Engineering, Water Environment Technology

Anne Farewell

University of Gothenburg

Jie Sun

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Fuzhou University

Oskar Modin

Chalmers, Architecture and Civil Engineering, Water Environment Technology

Biofilm

25902075 (eISSN)

Vol. 6 100161

Controlling the function of bioelectrochemical systems in Wastwater treatment processes

J. Gust. Richert stiftelse (2022-00757), 2022-08-01 -- 2024-05-30.

Bioelectrochemical systems for sustainable wastewater management

Formas (2018-00622), 2019-01-01 -- 2021-12-31.

Subject Categories

Ecology

Microbiology

DOI

10.1016/j.bioflm.2023.100161

PubMed

37859795

More information

Latest update

10/27/2023