title: The rhizosphere and PAH amendment mediate impacts on functional and structural bacterial diversity in sandy peat soil.
abstract: To reveal the degradation capacity of bacteria in PAH polluted soil and rhizosphere we combined bacterial extradiol ring-cleavage dioxygenase and 16S rRNA analysis in Betula pubescens rhizoremediation. Characterisation of the functional bacterial community by RFLP revealed novel environmental dioxygenases, and their putative hosts were studied by 16S rRNA amplification. Plant rhizosphere and PAH amendment effects were detected by the RFLP/T-RFLP analysis. Functional species richness increased in the birch rhizosphere and PAH amendment impacted the compositional diversity of the dioxygenases and the structural 16S rRNA community. A shift from an Acidobacteria and Verrucomicrobia dominated to an Alpha- and Betaproteobacteria dominated community structure was detected in polluted soil. Clone sequence analysis indicated catabolic significance of Burkholderia in PAH polluted soil. These results advance our understanding of rhizoremediation and unveil the extent of uncharacterized functional bacteria to benefit bioremediation by facilitating the development of the molecular tool box to monitor bacterial populations in biodegradation.
authors.affiliation: Department of Biological and Environmental Sciences, General Microbiology, University of Helsinki, P.O. Box 56, (Biocenter 1C), 00014 Helsinki, Finland. kim.yrjala@helsinki.fi
authors.forename: Kim
authors.initials: K
authors.lastname: Yrjälä
authors.forename: Anna-Kaisa
authors.initials: AK
authors.lastname: Keskinen
authors.forename: Marja-Leena
authors.initials: ML
authors.lastname: Akerman
authors.forename: Carola
authors.initials: C
authors.lastname: Fortelius
authors.forename: Timo P
authors.initials: TP
authors.lastname: Sipilä
mesh_terms: D001419:Bacteria / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001673:Biodegradation, Environmental; D044822:Biodiversity; D004269:DNA, Bacterial / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism* / Q000494:pharmacology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D004269:DNA, Bacterial; D011084:Polycyclic Aromatic Hydrocarbons; D012336:RNA, Ribosomal, 16S; D012989:Soil Pollutants