Electrical current generation in microbial electrolysis cells by hyperthermophilic archaea Ferroglobus placidus and Geoglobus ahangari

Yasemin D. Yilmazel, Xiuping Zhu, Kyoung-Yeol Kim, Dawn E. Holmes, Bruce E. Logan

Research output: Contribution to journalArticlepeer-review

35 Scopus citations


Few microorganisms have been examined for current generation under thermophilic (40–65 °C) or hyperthermophilic temperatures (≥ 80 °C) in microbial electrochemical systems. Two iron-reducing archaea from the family Archaeoglobaceae, Ferroglobus placidus and Geoglobus ahangari, showed electro-active behavior leading to current generation at hyperthermophilic temperatures in single-chamber microbial electrolysis cells (MECs). A current density (j) of 0.68 ± 0.11 A/m2 was attained in F. placidus MECs at 85 °C, and 0.57 ± 0.10 A/m2 in G. ahangari MECs at 80 °C, with an applied voltage of 0.7 V. Cyclic voltammetry (CV) showed that both strains produced a sigmoidal catalytic wave, with a mid-point potential of − 0.39 V (vs. Ag/AgCl) for F. placidus and − 0.37 V for G. ahangari. The comparison of CVs using spent medium and turnover CVs, coupled with the detection of peaks at the same potentials in both turnover and non-turnover conditions, suggested that mediators were not used for electron transfer and that both archaea produced current through direct contact with the electrode. These two archaeal species, and other hyperthermophilic exoelectrogens, have the potential to broaden the applications of microbial electrochemical technologies for producing biofuels and other bioelectrochemical products under extreme environmental conditions.
Original languageEnglish (US)
Pages (from-to)142-149
Number of pages8
StatePublished - Oct 2 2017
Externally publishedYes

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUS-I1-003-13
Acknowledgements: This research was supported by Global Climate Energy Project (GCEP, 134106) and the King Abdullah University of Science and Technology (KAUST, award KUS-I1-003-13). We thank the Penn State Microscopy and Cytometry Facility – University Park, PA for assistance with SEM analysis.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.


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