title: Effects of organochlorines on microbial diversity and community structure in Phragmites australis rhizosphere.
abstract: This study investigated the impacts of an organochlorine (OC, γ-hexachlorocyclohexane and chlorobenzenes) mixture on microbial communities associated to Phragmites australis rhizosphere. Seventy-eight distinct colony morphotypes were isolated, cultivated and analysed by 16S rDNA sequence analysis. Toxicity tests confirmed sensitivity (e.g. Hevizibacter, Acidovorax) or tolerance (e.g. Bacillus, Aeromonas, Pseudomonas, Sphingomonas) of isolates. Rhizosphere analysis by pyrosequencing showed the microbial adaptation induced by OC exposure. Among the most abundant molecular operational taxonomic units, 80 % appeared to be tolerant (55 % opportunist, 25 % unaffected) and 20 % sensitive. P. australis rhizosphere exposed to OCs was dominated by phylotypes related to α-, β- and γ-Proteobacteria. Specific genera were identified which were previously described as chlorinated organic pollutant degraders: Sphingomonas sp., Pseudomonas sp., Devosia sp. and Sphingobium sp. P. australis could be suitable plants to maintain their rhizosphere active microbial population which can tolerate OCs and potentially improve the OC remediation process in part by biodegradation.
authors: Laboratoire d'Ecologie Alpine, UMR CNRS n°5553, Université Joseph Fourier, BP 53, 38041, Grenoble Cedex 09, France.
authors: Angélique
authors: A
authors: San Miguel
authors: Julien
authors: J
authors: Roy
authors: Jérôme
authors: J
authors: Gury
authors: Armelle
authors: A
authors: Monier
authors: Eric
authors: E
authors: Coissac
authors: Patrick
authors: P
authors: Ravanel
authors: Roberto A
authors: RA
authors: Geremia
authors: Muriel
authors: M
authors: Raveton
mesh_terms: D001419:Bacteria / Q000145:classification / Q000187:drug effects* / Q000235:genetics; D058448:Biota / Q000187:drug effects*; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D006843:Hydrocarbons, Chlorinated / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010944:Plants; D006109:Poaceae / Q000254:growth & development*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D058441:Rhizosphere; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D006843:Hydrocarbons, Chlorinated; D012336:RNA, Ribosomal, 16S; D012989:Soil Pollutants