Extracellular electron transfer-dependent anaerobic oxidation of ammonium by anammox bacteria
AuthorsShaw, Dario R.
Gralnick, Jeffrey A.
van Niftrik, Laura
Jetten, Mike S. M.
KAUST DepartmentBiological and Environmental Sciences and Engineering (BESE) Division
Environmental Biotechnology Research Group
Environmental Science and Engineering Program
Water Desalination and Reuse Center (WDRC), Biological and Environmental Science & Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
Water Desalination and Reuse Research Center (WDRC)
KAUST Grant NumberFCC/1/1971-33-01
Online Publication Date2020-04-28
Print Publication Date2020-12
Permanent link to this recordhttp://hdl.handle.net/10754/662678
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AbstractAnaerobic ammonium oxidation (anammox) bacteria contribute significantly to the global nitrogen cycle and play a major role in sustainable wastewater treatment. Anammox bacteria convert ammonium (NH4+) to dinitrogen gas (N2) using intracellular electron acceptors such as nitrite (NO2−) or nitric oxide (NO). However, it is still unknown whether anammox bacteria have extracellular electron transfer (EET) capability with transfer of electrons to insoluble extracellular electron acceptors. Here we show that freshwater and marine anammox bacteria couple the oxidation of NH4+ with transfer of electrons to insoluble extracellular electron acceptors such as graphene oxide or electrodes in microbial electrolysis cells. 15N-labeling experiments revealed that NH4+ was oxidized to N2 via hydroxylamine (NH2OH) as intermediate, and comparative transcriptomics analysis revealed an alternative pathway for NH4+ oxidation with electrode as electron acceptor. Complete NH4+ oxidation to N2 without accumulation of NO2− and NO3− was achieved in EET-dependent anammox. These findings are promising in the context of implementing EET-dependent anammox process for energy-efficient treatment of nitrogen.
CitationShaw, D. R., Ali, M., Katuri, K. P., Gralnick, J. A., Reimann, J., Mesman, R., … Saikaly, P. E. (2020). Extracellular electron transfer-dependent anaerobic oxidation of ammonium by anammox bacteria. Nature Communications, 11(1). doi:10.1038/s41467-020-16016-y
SponsorsThis work was supported by Center Competitive Funding Program (FCC/1/1971-33-01) to P.E.S. from King Abdullah University of Science and Technology (KAUST). M.S.M.J. was supported by ERC AG 232937 and 339880 and SIAM OCW/NWO 024002002.
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Title: Electrode-dependent anaerobic ammonium oxidation by anammox bacteria. Publication Date: 2019-02-20. bioproject: PRJNA517785 Handle: 10754/666496
Title: DarioRShaw/Electro-anammox: Metagenomics and trasncriptomics analysis of anodic biofilms of anammox bacteria that perform electrode-dependent anaerobic ammonium oxidation. Publication Date: 2019-01-31. github: DarioRShaw/Electro-anammox Handle: 10754/667869