Peura, Sari
- Institutionen för skoglig mykologi och växtpatologi, Sveriges lantbruksuniversitet
- Jyväskylän yliopisto
Sammanfattning
The role of anaerobic CH4 oxidation in controlling lake sediment CH4 emissions remains unclear. Therefore, we tested how relevant EAs (SO42-, NO3-, Fe3+, Mn4+, O-2) affect CH4 production and oxidation in the sediments of two shallow boreal lakes. The changes induced to microbial communities by the addition of Fe3+ and Mn4+ were studied using next-generation sequencing targeting the 16S rRNA and methyl-coenzyme M reductase (mcrA) genes and mcrA transcripts. Putative anaerobic CH4-oxidizing archaea (ANME-2D) and bacteria (NC 10) were scarce (up to 3.4% and 0.5% of archaeal and bacterial 16S rRNA genes, respectively), likely due to the low environmental stability associated with shallow depths. Consequently, the potential anaerobic CH4 oxidation (0-2.1 nmol g(-1) (dry weight (DW)) d(-1)) was not enhanced by the addition of EAs, nor important in consuming the produced CH4 (0.6-82.5 nmol g(-1) (DW)d-1). Instead, the increased EA availability suppressed CH4 production via the outcompetition of methanogens by anaerobically respiring bacteria and via the increased protection of organic matter from microbial degradation induced by Fe3+ and Mn4+. Future studies could particularly assess whether anaerobic CH4 oxidation has any ecological relevance in reducing CH4 emissions from the numerous CH4-emitting shallow lakes in boreal and tundra landscapes.
Nyckelord
lake; sediment; methanogenesis; methane oxidation; 16S rRNA; mcrA
Publicerad i
FEMS Microbiology Ecology
2017, volym: 93, nummer: 7, artikelnummer: fix078
SLU författare
UKÄ forskningsämne
Ekologi
Publikationens identifierare
- DOI: https://doi.org/10.1093/femsec/fix078
Permanent länk till denna sida (URI)
https://res.slu.se/id/publ/89888