title: Structure of hydrocarbonoclastic nitrate-reducing bacterial communities in bioturbated coastal marine sediments.
abstract: The organisation of denitrifying microorganisms in oil-polluted bioturbated sediments was investigated in mesocosms under conditions as closer as possible to that observed in the environment. Molecular and culture-dependent approaches revealed that denitrifying Gammaproteobacteria were abundant in oil-polluted and bioturbated sediments suggesting that they may play a key role in hydrocarbon degradation in the environment. T-RFLP and gene libraries analyses targeting nirS gene showed that denitrifying microbial communities structure was slightly affected by either the addition of Hediste diversicolor or crude oil revealing the metabolic versatility of denitrifying microorganisms. From oil-polluted sediments, distinct denitrifying hydrocarbonoclastic bacterial consortia were obtained by enrichment cultures on high molecular weight polyaromatic hydrocarbons (PAHs) (dibenzothiophene, fluoranthene, pyrene and chrysene) under nitrate-reducing conditions. Interestingly, molecular characterisation of the consortia showed that the denitrifying communities obtained from oiled microcosms with addition of H. diversicolor were different to that observed without H. diversicolor addition, especially with fluoranthene and chrysene revealing the bacterial diversity involved in the degradation of these PAHs.
authors.affiliation: Equipe Environnement et Microbiologie, IPREM UMR CNRS 5254, Université de Pau et des Pays de l'Adour, Pau Cedex, France.
authors.forename: Magalie
authors.initials: M
authors.lastname: Stauffert
authors.forename: Cristiana
authors.initials: C
authors.lastname: Cravo-Laureau
authors.forename: Robert
authors.initials: R
authors.lastname: Duran
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D020563:Gammaproteobacteria / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D019015:Geologic Sediments / Q000382:microbiology*; D006838:Hydrocarbons / Q000378:metabolism; D009566:Nitrates / Q000378:metabolism*; D009572:Nitrite Reductases / Q000235:genetics; D059392:Petroleum Pollution; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D006838:Hydrocarbons; D009566:Nitrates; D009572:Nitrite Reductases
keywords: PAH biodegradation; T-RFLP; bioturbation; cultivable bacteria; nirS gene; petroleum pollution