Improving electroautotrophic ammonium production from nitrogen gas by simultaneous carbon dioxide fixation in a dual-chamber microbial electrolysis cell

Lixia Zhang; Chang Tian; Haoran Wang; Wenzhi Gu; Decong Zheng; Mengyao Cui; Xiaomei Wang; Xiaohong He; Guoqiang Zhan; Daping Li

doi:10.1016/j.bioelechem.2021.108044

Improving electroautotrophic ammonium production from nitrogen gas by simultaneous carbon dioxide fixation in a dual-chamber microbial electrolysis cell

Bioelectrochemistry. 2022 Apr:144:108044. doi: 10.1016/j.bioelechem.2021.108044. Epub 2021 Dec 24.

Authors

Lixia Zhang¹, Chang Tian², Haoran Wang³, Wenzhi Gu², Decong Zheng², Mengyao Cui², Xiaomei Wang², Xiaohong He², Guoqiang Zhan⁴, Daping Li⁵

Affiliations

¹ CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China.
³ CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; College of Life Sciences, Sichuan University, Chengdu 610065, China.
⁴ CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China. Electronic address: zhangq@cib.ac.cn.
⁵ CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China. Electronic address: lidp@cib.ac.cn.

PMID: 34974371
DOI: 10.1016/j.bioelechem.2021.108044

Abstract

Microbial electrosynthesis is a promising technology for high-value added products generation from organic and inorganic waste. In this work, autotrophic dual-chamber microbial electrolysis cells (MECs) were set up for N₂ fixation at -0.9 V vs Ag/AgCl (sat. KCl) cathodic potential under ambient conditions. Higher NH₄⁺ production yield (average value of 0.35 µmol h^-1 cm^-2, normalized to cathode surface area) and higher faradaic efficiency (FE, 20.25%) were obtained with intermittent addition of N₂ and CO₂, while the yield and FE were only 0.018 µmol h^-1 cm^-2 and 4.21% in the absence of CO₂. Furthermore, cyclic voltammograms (CV) explained the bioelectrochemical behavior of N₂ reduction was coupled with CO₂ reduction in the autotrophic MECs. Microbial community analysis and functional prediction in the cathodic chamber revealed that Xanthobacter and Hydrogenophaga played as producers for N₂ and CO₂ fixation and Pannonibacter acting as a decomposer for converting organic nitrogen to ammonium. This work not only provided an optional bioelectrocatalytic method for N₂ fixation with negative CO₂-emissions but also revealed the mechanism of simultaneous fixation of N₂ and CO₂ via Calvin cycle in autotrophic MECs.

Keywords: Ammonium production; Bioelectrochemical nitrogen fixation; CO(2) reduction; Electroautotrophic; Microbial electrosynthesis.

MeSH terms

Carbon Dioxide*

Substances

Carbon Dioxide