title: Monitoring of accelerated naphthalene-biodegradation in a bioaugmented soil slurry.
abstract: The effect of microbial inoculation on the mineralization of naphthalene in a bioslurry treatment was evaluated in soil slurry microcosms. Inoculation by Pseudomonas putida G7 carrying the naphthalene dioxygenase (nahA) gene resulted in rapid mineralization of naphthalene, whereas indigenous microorganisms in the PAH-contaminated soil required a 28 h adaptation period before significant mineralization occurred. The number of nahA-like gene copies increased in both the inoculated and non-inoculated soil as mineralization proceeded, indicating selection towards naphthalene dioxygenase producing bacteria in the microbial community. In addition, 16S rRNA analysis by denaturing gradient gel electrophoresis (DGGE) analysis showed that significant selection occurred in the microbial community as a result of biodegradation. However, the indigenous soil bacteria were not able to compete with the P. putida G7 inoculum adapted to naphthalene biodegradation, even though the soil microbial community slightly suppressed naphthalene mineralization by P. putida G7.
authors.affiliation: VTT Biotechnology, P.O. Box 1500, 02044 VTT, Finland. reetta.piskonen@vtt.fi
authors.forename: Reetta
authors.initials: R
authors.lastname: Piskonen
authors.forename: Mari
authors.initials: M
authors.lastname: Nyyssönen
authors.forename: Tiina
authors.initials: T
authors.lastname: Rajamäki
authors.forename: Merja
authors.initials: M
authors.lastname: Itävaara
mesh_terms: D001673:Biodegradation, Environmental; D049308:Dioxygenases; D009097:Multienzyme Complexes / Q000378:metabolism; D009281:Naphthalenes / Q000378:metabolism*; D010105:Oxygenases / Q000378:metabolism; D011084:Polycyclic Aromatic Hydrocarbons; D016958:Pseudomonas putida / Q000201:enzymology* / Q000378:metabolism; D012329:RNA, Bacterial / Q000032:analysis; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D012641:Selection, Genetic; D012987:Soil; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism
chemical_list: D009097:Multienzyme Complexes; D009281:Naphthalenes; D011084:Polycyclic Aromatic Hydrocarbons; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012987:Soil; D012989:Soil Pollutants; C031721:naphthalene; D010105:Oxygenases; D049308:Dioxygenases; C038703:naphthalene dioxygenase