Anaerobic Eury- and Crenarchaeota inhabit ectomycorrhizas of boreal forest Scots pine

Members of the euryarchaeotal genera Methanolobus and Halobacterium as well as group 11c Crenarchaeota were enriched from ectomycorrhizal samples and cultured under anaerobic conditions 16S rRNA gene sequences of Methanolobus were obtained in a H-2 + CO2 atmosphere and autofluorescent putatively methanogenic microbial cells were detected by epifluorescence microscopy of the anaerobic methane-producing enrichment cultures Halobacterium and group 11c Crenarchaeota grew anaerobically when either H-2 or CH4 was added to the atmosphere Group 11c Crenarchaeota were also enriched under aerobic conditions on mineral media but only when methane or methanol was added as carbon sources The 165 rRNA gene sequences of 11c Crenarchaeota grown under both anaerobic and aerobic conditions were highly similar Our study demonstrates the growth of group 11c Crenarchaeota and Halobacteria derived from non-extreme soil environment in non-saline enrichments under anaerobic conditions The results suggest that 11c Crenarchaeota may play a role in the cycling of C-1 substrates in the boreal forest soil ecosystem (C) 2010 Elsevier Masson SAS All rights reserved