How elevated pCO2 modifies total and metabolically active bacterial communities in the rhizosphere of two perennial grasses grown under field conditions

Marylin Jossi (1) , Nathalie Fromin (1, 2) , Sonia Tarnawski (1) , Florian Kohler (3, 4) , François Gillet (3, 5, 6) , Michel Aragno (1) , Jérôme Hamelin (1)

1 Microbiology laboratory
2 CEFE - Centre d’Ecologie Fonctionnelle et Evolutive
3 Laboratoire Sol & Végétation
4 WSL Lausanne
5 LCE - Laboratoire Chrono-environnement (UMR 6249)
6 ECOS - Laboratoire des systèmes écologiques

The response of total (DNA-based analysis) and active (RNA-based analysis) bacterial communities to a pCO2 increase under field conditions was assessed using two perennial grasses: the nitrophilic Lolium perenne and the oligonitrophilic Molinia coerulea. PCR- and reverse transcriptase-PCR denaturing gradient gel electrophoresis analysis of 16S rRNA genes generated contrasting profiles. The pCO2 increase influenced mainly the active and root-associated component of the bacterial community. Bacterial groups responsive to the pCO2 increase were identified by sequencing of corresponding denaturing gradient gel electrophoresis bands. About 50% of retrieved sequences were affiliated to Proteobacteria. Our data suggest that Actinobacteria in soil and Myxococcales (Deltaproteobacteria) in root are stimulated under elevated pCO2.

Mots clés: Bacterial community; 16S rRNA; DGGE; global change; carbon dioxide; FACE

Domaines: Biodiversité et Ecologie; Milieux et Changements globaux; Interactions entre organismes; Ecosystèmes

Marylin Jossi, Nathalie Fromin, Sonia Tarnawski, Florian Kohler, François Gillet, et al.. How elevated pCO2 modifies total and metabolically active bacterial communities in the rhizosphere of two perennial grasses grown under field conditions. FEMS Microbiology Ecology, 2006, 55 (3), pp.339-350. ⟨10.1111/j.1574-6941.2005.00040.x⟩. ⟨hal-00442595⟩