title: Occurrence and diversity of naphthalene dioxygenase genes in soil microbial communities from the Maritime Antarctic.
abstract: The diversity of naphthalene dioxygenase genes (ndo) in soil environments from the Maritime Antarctic was assessed, dissecting as well the influence of the two vascular plants that grow in the Antarctic: Deschampsia antarctica and Colobanthus quitensis. Total community DNA was extracted from bulk and rhizosphere soil samples from Jubany station and Potter Peninsula, South Shetland Islands. ndo genes were amplified by a nested PCR and analysed by denaturant gradient gel electrophoresis approach (PCR-DGGE) and cloning and sequencing. The ndo-DGGE fingerprints of oil-contaminated soil samples showed even and reproducible patterns, composed of four dominant bands. The presence of vascular plants did not change the relative abundance of ndo genotypes compared with bulk soil. For non-contaminated sites, amplicons were not obtained for all replicates and the variability among the fingerprints was comparatively higher, likely reflecting a lower abundance of ndo genes. The phylogenetic analyses showed that all sequences were affiliated to the nahAc genes closely related to those described for Pseudomonas species and related mobile genetic elements. This study revealed that a microdiversity of nahAc-like genes exists in microbial communities of Antarctic soils and quantitative PCR indicated that their relative abundance was increased in response to anthropogenic sources of pollution.
authors.affiliation: Julius Kühn-Institute, Federal Research Centre for Cultivated Plants (JKI), Braunschweig, Germany. flocco@ffyb.uba.ar
authors.forename: Cecilia G
authors.initials: CG
authors.lastname: Flocco
authors.forename: Newton C M
authors.initials: NC
authors.lastname: Gomes
authors.forename: Walter
authors.initials: W
authors.lastname: Mac Cormack
authors.forename: Kornelia
authors.initials: K
authors.lastname: Smalla
mesh_terms: D000864:Antarctic Regions; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D049308:Dioxygenases; D014644:Genetic Variation; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000235:genetics*; D010105:Oxygenases / Q000235:genetics*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011549:Pseudomonas / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D012988:Soil Microbiology
chemical_list: D004269:DNA, Bacterial; D009097:Multienzyme Complexes; D010105:Oxygenases; D049308:Dioxygenases; C038703:naphthalene dioxygenase