Viability of differentiated epilithic bacterial communities in the River Garonne (SW France)

Autor: Erwann Y. Madigou, Frédéric Garabetian, Stéphanie Boulêtreau, E. Lyautey
Přispěvatelé: Centre National de la Recherche Scientifique (CNRS), Milieux aquatiques, écologie et pollutions (UR MALY), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
Rok vydání: 2009
Předmět:
Zdroj: Hydrobiologia
Hydrobiologia, Springer, 2010, 637 (1), pp.207-218. ⟨10.1007/s10750-009-9997-0⟩
ISSN: 1573-5117
0018-8158
DOI: 10.1007/s10750-009-9997-0
Popis: Epilithic bacterial community viability was assessed on natural biofilm assemblages from environmentally contrasting locations over a 17-months period to determine if it reflects environmental conditions or conditions within the biofilm assemblage. Vital state was assessed by membrane integrity using LIVE/DEAD® BacLight™ staining kit. Samples were regularly collected in a large river, up and downstream of a large urban centre. Epilithic biomasses were similar between sites irrespective of the distinct water quality but varied temporarily, peaking up to 48 g AFDM m−2. Bacterial community composition assessed by 16S rDNA based PCR-DGGE significantly differed between sites. Bacterial densities (median of 2.5 × 1011 cell g AFDM−1) were stable whatever the sample origin or biomass. Viable bacterial fractions ranged between 13 and 83% of the total bacterial densities and were correlated with hydrological stability indicators (average of 41.9% during stable water periods, 62.4% during intermediate flow regimes and 50.0% during flow instability) and seasonal parameters. At the river section and epilithic community scales, consistent bacterial densities per unit of biomass could reflect a biofilm assemblage carrying capacity while variable membrane integrity likely integrates changes in the vital state of the community under changing environmental conditions.
Databáze: OpenAIRE
Externí odkaz: