Enrichment of denitrifying anaerobic methane oxidizing microorganisms
- 8 October 2009
- journal article
- Published by Wiley in Environmental Microbiology Reports
- Vol. 1 (5), 377-384
- https://doi.org/10.1111/j.1758-2229.2009.00083.x
Abstract
The microorganisms responsible for anaerobic oxidation of methane (AOM) coupled to denitrification have not been clearly elucidated. Three recent publications suggested it can be achieved by a denitrifying bacterium with or without the involvement of anaerobic methanotrophic archaea. A key factor limiting the progress in this research field is the shortage of enrichment cultures performing denitrifying anaerobic methane oxidation (DAMO). In this study, DAMO cultures were enriched from mixed inoculum including sediment from a freshwater lake, anaerobic digester sludge and return activated sludge from a sewage treatment plant. Two reactors, operated at 35°C and at 22°C, respectively, showed simultaneous methane oxidation and nitrate reduction after several months of operation. Analysis of 16S rRNA gene clone libraries from the 35°C enrichment showed the presence of an archaeon closely related to other DAMO archaea and a dominated bacterium belonging to the yet uncultivated NC10 phylum. This culture preferred nitrite to nitrate as the electron acceptor. The present study suggests that the archaea are rather methanotrophs than methanogens. The highest denitrification rate achieved was 2.35 mmol NO3‐‐N gVSS−1 day−1. The culture enriched at 22°C contained the same NC10 bacterium observed in the culture enriched at 35°C but no archaea.Keywords
This publication has 20 references indexed in Scilit:
- Enrichment and Molecular Detection of Denitrifying Methanotrophic Bacteria of the NC10 PhylumApplied and Environmental Microbiology, 2009
- Denitrifying bacteria anaerobically oxidize methane in the absence of ArchaeaEnvironmental Microbiology, 2008
- Methyl sulfides as intermediates in the anaerobic oxidation of methaneEnvironmental Microbiology, 2007
- Denitrification with methane as external carbon sourceWater Research, 2007
- Novel microbial communities of the Haakon Mosby mud volcano and their role as a methane sinkNature, 2006
- A microbial consortium couples anaerobic methane oxidation to denitrificationNature, 2006
- Cooccurrence of Aerobic and Anaerobic Methane Oxidation in the Water Column of Lake PlußseeApplied and Environmental Microbiology, 2005
- Anaerobic Oxidation of Methane and AmmoniumAnnual Review of Microbiology, 2004
- Evidence of anoxic methane oxidation coupled to denitrificationWater Research, 2004
- A conspicuous nickel protein in microbial mats that oxidize methane anaerobicallyNature, 2003