title: Betaproteobacteria dominance and diversity shifts in the bacterial community of a PAH-contaminated soil exposed to phenanthrene.
abstract: 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.
authors.affiliation: CEA, DSV, iRTSV, Laboratoire de Chimie et Biologie des Métaux, Grenoble, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Martin
authors.forename: Stéphane
authors.initials: S
authors.lastname: Torelli
authors.forename: Denis
authors.initials: D
authors.lastname: Le Paslier
authors.forename: Agnès
authors.initials: A
authors.lastname: Barbance
authors.forename: Fabrice
authors.initials: F
authors.lastname: Martin-Laurent
authors.forename: David
authors.initials: D
authors.lastname: Bru
authors.forename: Roberto
authors.initials: R
authors.lastname: Geremia
authors.forename: Gérard
authors.initials: G
authors.lastname: Blake
authors.forename: Yves
authors.initials: Y
authors.lastname: Jouanneau
mesh_terms: D020562:Betaproteobacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D001673:Biodegradation, Environmental; D044822:Biodiversity; D008969:Molecular Sequence Data; D010616:Phenanthrenes / Q000378:metabolism*; D010802:Phylogeny; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D010616:Phenanthrenes; D011084:Polycyclic Aromatic Hydrocarbons; D012989:Soil Pollutants; C031181:phenanthrene