Betaproteobacteria dominance and diversity shifts in the bacterial community of a PAH-contaminated soil exposed to phenanthrene.

Florence Martin (1) , Stéphane Torelli (1, 2) , Denis Le Paslier (3) , Agnès Barbance (3) , Fabrice Martin-Laurent (4) , David Bru (4) , Roberto Geremia (5) , Gérard Blake (6) , Yves Jouanneau (1)

1 LCBM - UMR 5249 - Laboratoire de Chimie et Biologie des Métaux
2 DCM - Département de Chimie Moléculaire
3 GENOSCOPE - Genoscope - Centre national de séquençage [Evry]
4 Agroécologie [Dijon]
5 LECA - Laboratoire d'Ecologie Alpine
6 LOCIE - LabOratoire proCédés énergIe bâtimEnt

In this study, the PAH-degrading bacteria of a constructed wetland collecting road runoff has been studied through DNA stable isotope probing. Microcosms were spiked with (13)C-phenanthrene at 34 or 337 ppm, and bacterial diversity was monitored over a 14-day period. At 337 ppm, PAH degraders became dominated after 5 days by Betaproteobacteria, including novel Acidovorax, Rhodoferax and Hydrogenophaga members, and unknown bacteria related to Rhodocyclaceae. The prevalence of Betaproteobacteria was further demonstrated by phylum-specific quantitative PCR, and was correlated with a burst of phenanthrene mineralization. Striking shifts in the population of degraders were observed after most of the phenanthrene had been removed. Soil exposed to 34 ppm phenanthrene showed a similar population of degraders, albeit only after 14 days. Results demonstrate that specific Betaproteobacteria are involved in the main response to soil PAH contamination, and illustrate the potential of SIP approaches to investigate PAH biodegradation in soil.

Mots clés: 16S rRNA sequences; stable isotope probing; PAH degradation; phenanthrene; betaproteobacteria

Domaines: Biochimie [q-bio.BM]

Florence Martin, Stéphane Torelli, Denis Le Paslier, Agnès Barbance, Fabrice Martin-Laurent, et al.. Betaproteobacteria dominance and diversity shifts in the bacterial community of a PAH-contaminated soil exposed to phenanthrene.. Environmental Pollution, 2012, 162, pp.345-53. ⟨10.1016/j.envpol.2011.11.032⟩. ⟨hal-01063697⟩