title: Response of a diuron-degrading community to diuron exposure assessed by real-time quantitative PCR monitoring of phenylurea hydrolase A and B encoding genes.
abstract: A real-time quantitative PCR method was developed to detect and quantify phenlylurea hydrolase genes' (puhA and puhB) sequences from environmental DNA samples to assess diuron-degrading genetic potential in some soil and sediment microbial communities. In the soil communities, mineralization rates (determined with [ring-¹⁴C]-labeled diuron) were linked to diuron-degrading genetic potentials estimated from puhB number copies, which increased following repeated diuron treatments. In the sediment communities, mineralization potential did not depend solely on the quantity of puhB copies, underlining the need to assess gene expression. In the sediment samples, both puhB copy numbers and mineralization capacities were highly conditioned by whether or not diuron-treated soil was added. This points to transfers of degradative potential from soils to sediments. No puhA gene was detected in soil and sediment DNA extracts. Moreover, some sediments exhibited high diuron mineralization potential even though puhB genes were not detected, suggesting the existence of alternative diuron degradation pathways.
authors.affiliation: Irstea, UR MALY, 3 Bis Quai Chauveau-CP 220, 69336 Lyon, France. stephane.pesce@irstea.fr
authors.forename: Stéphane
authors.initials: S
authors.lastname: Pesce
authors.forename: Jérémie
authors.initials: J
authors.lastname: Beguet
authors.forename: Nadine
authors.initials: N
authors.lastname: Rouard
authors.forename: Marion
authors.initials: M
authors.lastname: Devers-Lamrani
authors.forename: Fabrice
authors.initials: F
authors.lastname: Martin-Laurent
mesh_terms: D000581:Amidohydrolases / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001419:Bacteria / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001673:Biodegradation, Environmental; D004237:Diuron / Q000378:metabolism*; D006540:Herbicides / Q000378:metabolism*; D008969:Molecular Sequence Data; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D016415:Sequence Alignment; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D006540:Herbicides; D012989:Soil Pollutants; D004237:Diuron; D000581:Amidohydrolases; C433926:phenylurea hydrolase