Funding Information This work was financially supported by the China National Critical Project for Science and Technology on Water Pollution Prevention and Control under Grant no. 2012ZX07101-012-03 and the National 863 Project of China with Grant no. 2006AA06Z327.
Molecular characterization of a microbial consortium involved in methane oxidation coupled to denitrification under micro-aerobic conditions
Article first published online: 19 NOV 2013
© 2013 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Volume 7, Issue 1, pages 64–76, January 2014
How to Cite
Liu, J., Sun, F., Wang, L., Ju, X., Wu, W. and Chen, Y. (2014), Molecular characterization of a microbial consortium involved in methane oxidation coupled to denitrification under micro-aerobic conditions. Microbial Biotechnology, 7: 64–76. doi: 10.1111/1751-7915.12097
- Issue published online: 10 DEC 2013
- Article first published online: 19 NOV 2013
- Manuscript Accepted: 7 OCT 2013
- Manuscript Received: 19 AUG 2013
- China National Critical Project for Science and Technology on Water Pollution Prevention and Control. Grant Number: 2012ZX07101-012-03
- National 863 Project of China. Grant Number: 2006AA06Z327
Methane can be used as an alternative carbon source in biological denitrification because it is nontoxic, widely available and relatively inexpensive. A microbial consortium involved in methane oxidation coupled to denitrification (MOD) was enriched with nitrite and nitrate as electron acceptors under micro-aerobic conditions. The 16S rRNA gene combined with pmoA phylogeny of methanotrophs and nirK phylogeny of denitrifiers were analysed to reveal the dominant microbial populations and functional microorganisms. Real-time quantitative polymerase chain reaction results showed high numbers of methanotrophs and denitrifiers in the enriched consortium. The 16S rRNA gene clone library revealed that Methylococcaceae and Methylophilaceae were the dominant populations in the MOD ecosystem. Phylogenetic analyses of pmoA gene clone libraries indicated that all methanotrophs belonged to Methylococcaceae, a type I methanotroph employing the ribulose monophosphate pathway for methane oxidation. Methylotrophic denitrifiers of the Methylophilaceae that can utilize organic intermediates (i.e. formaldehyde, citrate and acetate) released from the methanotrophs played a vital role in aerobic denitrification. This study is the first report to confirm micro-aerobic denitrification and to make phylogenetic and functional assignments for some members of the microbial assemblages involved in MOD.