Influent:Real wastewater
Comammox System:Sequential batch reactor coupling anammox and n-DAMO
reactor:Sequential batch reactor (SBR)
Medium:Suspended-sludge
Culture taken from:Enriched n-DAMO and anammox culture
Microorganism cultured:n-DAMO archaea and n-DAMO bacteria
Respiration:Anaerobic
Electron donor:Methane
Electron acceptor:Nitrite
PH:7.3–7.6
Temperature:Room temperature
HRT:nan
NH4–N Influent conc(mg/L):nan
NO2–N Influent conc(mg/L):nan
NO3–N Influent conc(mg/L):nan
NH4–N Effluent (mg N/L):nan
NO2–N Effluent (mg N/L):nan
NO3-N Effluent (mg N/L):nan
NH4–N removal rate mg/L/d:40
NO2–N removal rate mg/L/d:nan
NO3-N removal rate mg/L/d:40
TN Removal rate (mg N/L/d):nan
Authors:Haroon et al., 2013
Title:Anaerobic oxidation of methane coupled to nitrate reduction in a novel archaeal lineage
Pubmed link:None
Full research link:Link
Abstract:Anaerobic oxidation of methane (AOM) is critical for controlling the flux of methane from anoxic environments. AOM coupled to iron1, manganese1 and sulphate2 reduction have been demonstrated in consortia containing anaerobic methanotrophic (ANME) archaea. More recently it has been shown that the bacterium Candidatus ‘Methylomirabilis oxyfera’ can couple AOM to nitrite reduction through an intra-aerobic methane oxidation pathway3. Bioreactors capable of AOM coupled to denitrification have resulted in the enrichment of ‘M. oxyfera’ and a novel ANME lineage, ANME-2d4,5. However, as ‘M. oxyfera’ can independently couple AOM to denitrification, the role of ANME-2d in the process is unresolved. Here, a bioreactor fed with nitrate, ammonium and methane was dominated by a single ANME-2d population performing nitrate-driven AOM. Metagenomic, single-cell genomic and metatranscriptomic analyses combined with bioreactor performance and 13C- and 15N-labelling experiments show that ANME-2d is capable of independent AOM through reverse methanogenesis using nitrate as the terminal electron acceptor. Comparative analyses reveal that the genes for nitrate reduction were transferred laterally from a bacterial donor, suggesting selection for this novel process within ANME-2d. Nitrite produced by ANME-2d is reduced to dinitrogen gas through a syntrophic relationship with an anaerobic ammonium-oxidizing bacterium, effectively outcompeting ‘M. oxyfera’ in the system. We propose the name Candidatus ‘Methanoperedens nitroreducens’ for the ANME-2d population and the family Candidatus ‘Methanoperedenaceae’ for the ANME-2d lineage. We predict that ‘M. nitroreducens’ and other members of the ‘Methanoperedenaceae’ have an important role in linking the global carbon and nitrogen cycles in anoxic environments.