title: Distribution and activity of the anaerobic methanotrophic community in a nitrogen-fertilized Italian paddy soil.
abstract: In order to mitigate methane emissions from paddy fields, it is important to understand the sources and sinks. Most paddy fields are heavily fertilized with nitrite and nitrate, which can be used as electron acceptors by anaerobic methanotrophs. Here we show that slurry incubations of Italian paddy field soil with nitrate and13C-labelled methane have the potential for nitrate-dependent anaerobic oxidation of methane (79.9 nmol g-1dwd-1). Community analysis based on 16S rRNA amplicon sequencing and qPCR of the water-logged soil and the rhizosphere showed that anaerobic oxidation of methane-associated archaea (AAA), including Methanoperedens nitroreducens, comprised 9% (bulk soil) and 1% (rhizosphere) of all archaeal reads. The NC10 phylum bacteria made up less than 1% of all bacterial sequences. The phylogenetic analysis was complemented by qPCR showing that AAA ranged from 0.28 × 106to 3.9 × 10616S rRNA gene copies g-1dwin bulk soil and 0.27 × 106to 2.8 × 106in the rhizosphere. The abundance of NC10 phylum bacteria was an order of magnitude lower. Revisiting published diversity studies, we found that AAA have been detected, but not linked to methane oxidation, in several paddy fields. Our data suggest an important role of AAA in methane cycling in paddy fields.
authors: Radboud University, Department of Microbiology, Institute of Water and Wetland Research, Heyendaalseweg 135, 6525AJ, Nijmegen, The Netherlands.
authors: A
authors: A
authors: Vaksmaa
authors: Radboud University, Department of Microbiology, Institute of Water and Wetland Research, Heyendaalseweg 135, 6525AJ, Nijmegen, The Netherlands c.lueke@science.ru.nl.
authors: C
authors: C
authors: Lüke
authors: Radboud University, Department of Microbiology, Institute of Water and Wetland Research, Heyendaalseweg 135, 6525AJ, Nijmegen, The Netherlands.
authors: T
authors: T
authors: van Alen
authors: CREA - Council for Agricultural Research and Economics, Rice Research Unit, s.s.11 to Torino km 2.5, 13100 Vercelli, Italy.
authors: G
authors: G
authors: Valè
authors: CREA - Council for Agricultural Research and Economics, Rice Research Unit, s.s.11 to Torino km 2.5, 13100 Vercelli, Italy.
authors: E
authors: E
authors: Lupotto
authors: Radboud University, Department of Microbiology, Institute of Water and Wetland Research, Heyendaalseweg 135, 6525AJ, Nijmegen, The Netherlands.
authors: M S M
authors: MS
authors: Jetten
authors: Radboud University, Department of Microbiology, Institute of Water and Wetland Research, Heyendaalseweg 135, 6525AJ, Nijmegen, The Netherlands.
authors: K F
authors: KF
authors: Ettwig
keywords: 16S rRNA gene; AAA; Methanoperedens nitroreducens; amplicon sequencing; anaerobic oxidation of methane; microbial community; paddy fields; rice rhizosphere