title: Community structure and PAH ring-hydroxylating dioxygenase genes of a marine pyrene-degrading microbial consortium.
abstract: Marine microbial consortium UBF, enriched from a beach polluted by the Prestige oil spill and highly efficient in degrading this heavy fuel, was subcultured in pyrene minimal medium. The pyrene-degrading subpopulation (UBF-Py) mineralized 31 % of pyrene without accumulation of partially oxidized intermediates indicating the cooperation of different microbial components in substrate mineralization. The microbial community composition was characterized by culture dependent and PCR based methods (PCR-DGGE and clone libraries). Molecular analyses showed a highly stable community composed by Alphaproteobacteria (84 %, Breoghania, Thalassospira, Paracoccus, and Martelella) and Actinobacteria (16 %, Gordonia). The members of Thalasosspira and Gordonia were not recovered as pure cultures, but five additional strains, not detected in the molecular analysis, that classified within the genera Novosphingobium, Sphingopyxis, Aurantimonas (Alphaproteobacteria), Alcanivorax (Gammaproteobacteria) and Micrococcus (Actinobacteria), were isolated. None of the isolates degraded pyrene or other PAHs in pure culture. PCR amplification of Gram-positive and Gram-negative dioxygenase genes did not produce results with any of the cultured strains. However, sequences related to the NidA3 pyrene dioxygenase present in mycobacterial strains were detected in UBF-Py consortium, suggesting the representative of Gordonia as the key pyrene degrader, which is consistent with a preeminent role of actinobacteria in pyrene removal in coastal environments affected by marine oil spills.
authors.affiliation: Department of Microbiology, University of Barcelona, Diagonal 643, 08028, Barcelona, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Gallego
authors.forename: Joaquim
authors.initials: J
authors.lastname: Vila
authors.forename: Margalida
authors.initials: M
authors.lastname: Tauler
authors.forename: José María
authors.initials: JM
authors.lastname: Nieto
authors.forename: Philip
authors.initials: P
authors.lastname: Breugelmans
authors.forename: Dirk
authors.initials: D
authors.lastname: Springael
authors.forename: Magdalena
authors.initials: M
authors.lastname: Grifoll
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D001673:Biodegradation, Environmental; D058645:Denaturing Gradient Gel Electrophoresis; D049308:Dioxygenases / Q000235:genetics*; D005798:Genes, Bacterial; D052836:Heterotrophic Processes; D006900:Hydroxylation; D059013:Microbial Consortia / Q000235:genetics*; D008969:Molecular Sequence Data; D010616:Phenanthrenes / Q000378:metabolism; D010802:Phylogeny; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism*; D011721:Pyrenes / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*; D017422:Sequence Analysis, DNA
chemical_list: D010616:Phenanthrenes; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; D012336:RNA, Ribosomal, 16S; C030984:pyrene; D049308:Dioxygenases