Hyporheic biofilm development on artificial substrata, as a tool for assessing trophic status of aquatic systems : first results

Claret, C.

doi:10.1051/limn/1998011

Cited by 16 publications

(6 citation statements)

References 33 publications

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“…Viability can be assessed either at the cellular level to assess specific aspects of bacterial cell physiology or metabolism (Barer & Harwood, 1999;Bogosian & Bourneuf, 2001), or at the community level to evaluate the fitness of pluri-specific consortia and to estimate the active biomass fraction (Claret, 1998;Haglund et al, 2002;Luna et al, 2002;Sherr et al, 2002;Araya et al, 2003;Schumann et al, 2003;Tam et al, 2003). Membrane integrity, as an indicator of viability, was reported to remain several hours after lethal treatment although re-growth of injured cells is unlikely to occur unless cellular integrity is maintained (Villarino et al, 2000).…”

Section: Discussionmentioning

confidence: 99%

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

Lyautey

Boulêtreau

Madigou³

et al. 2009

Hydrobiologia

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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 Ò BacLight TM 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 9 10 11 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.

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Section: Discussionmentioning

confidence: 99%

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

Lyautey

Boulêtreau

Madigou³

et al. 2009

Hydrobiologia

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“…Previous studies showed that metabolic activity in the hyporheic zone depends on the quality and quantity of organic carbon (Brugger et al, 2001;Craft et al, 2002;Crenshaw et al, 2002). Dissolved organic carbon (DOC) is considered as the main source of carbon for hyporheic microorganisms (Claret et al, 1997;Claret, 1998a). The quality of DOC (i.e.…”

Section: Discussionmentioning

confidence: 99%

“…The quality of DOC (i.e. biodegradable versus refractory DOC content) has been shown to control ETS-active bacterial abundances early in colonisation of artificial substrata, while DOC concentrations limit biofilm development only in the latter phase of colonisation (Claret, 1998a). Higher contents of labile autochthonous organic matter cause higher microbial respiratory activity, reflected in higher ETS activity and oxygen consumption rate (Muri & Simčič, 2004).…”

Section: Discussionmentioning

confidence: 99%

Intensity of mineralization in the hyporheic zone of the prealpine river Bača (West Slovenia)

Simčić

Mori

2007

Hydrobiologia

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Respiratory electron transport system (ETS) activity and oxygen consumption in the interstitial water, and in the fine (i.e. silt) and coarse (sand) sediment fractions from the hyporheic zone of the prealpine river Bača (W Slovenia) have been measured in order to estimate the intensity of potential and actual carbon mineralization through microbial communities. Hyporheic samples from the river bed (RB) and gravel bars (GB) were compared. ETS activity and oxygen consumption of all fractions from the RB did not differ significantly from those from the GB. ETS activity and oxygen consumption of biofilm attached to 1 g of the silt were higher than of that attached to the same mass of the sand. A significant correlation between ETS activity and oxygen consumption indicated that the former should be a good indicator of intensity of bioactivity in hyporheic sediments. The ratio of ETS activity to oxygen consumption (ETS/R ratio) revealed that the oxygen consumption of microorganisms is responsible for approximately 60% of the metabolic potential in the hyporheic sediments. The contributions of different fractions of sediment to the total ETS activity differed between RB and GB. The contribution of microorganisms in the interstitial water and silt was higher in GB than in the RB, but the sand fraction contributed less to potential carbon loss in GB than in the RB. Average total respiratory carbon loss per volume through the hyporheic zone was higher in the RB than in GB. The main reasons suggested are the different intensity of exchange of surface water with the hyporheic zone, and the rate of consolidation of sediments, which is primarily a function of river hydrology and geomorphology.

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“…The sonicated subsamples were diluted (usually 100 times for coarse fraction and 1000 times for fine fraction). Two ml of sonicated and diluted subsample were stained with DAPI solution (final concentration 5 µg ml -1 ) for 5 min at room temperature (CLARET, 1998). After incubation, the suspension was filtered onto membrane (Millipore HTBP, pore size 0.2 µm) that was mounted in immersion oil and examined under an epifluorescence microscope (Olympus BX 60).…”

Section: Sample Processingmentioning

confidence: 99%

“…This could partly be explained by the heterogeneity of hyporheic sediments together with the practical difficulties of proper sampling of such a complex habitat (FISCHER et al, 1996). To avoid this problem, artificial substrates were used in several studies of the hyporheic biofilm (BÄR-LOCHER and MURDOCH, 1989;CLARET, 1998). FISCHER et al (1996) quantified bacterial abundance, biomass and activity on standardised sediment particles.…”

Section: Introductionmentioning

confidence: 99%

Hyporheic Biofilm Particulate Organic Carbon in a Small Lowland Stream (Sitka, Czech Republic): Structure and Distribution

Koutný¹,

Rulı́k

2007

International Review of Hydrobiology

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Bacterial abundance, biomass and particulate organic carbon (POC) were determined in the hyporheic sediments <1 mm. The fine fraction (< 0.063 mm) and coarse fraction (0.063-1 mm) were analysed separately. The coarse fraction was dominant (95.5%) and its POC content contributed the major proportion (on average 65%) of the total POC (TPOC). The changes in spatial distribution of TPOC were due to the variation in POC in the fine fraction. Bacteria in the fine fraction contributed on average to 62.9% of the total bacterial abundance and to 51.7% of the total bacterial biomass, despite the fact that the fine fraction represented only ~4.5% of the sediment <1 mm. Our results stress the importance of the fine sediment fraction for bacteria as well as for spatio-temporal distribution of biofilm POC.

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Hyporheic biofilm development on artificial substrata, as a tool for assessing trophic status of aquatic systems : first results

Cited by 16 publications

References 33 publications

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

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

Intensity of mineralization in the hyporheic zone of the prealpine river Bača (West Slovenia)

Hyporheic Biofilm Particulate Organic Carbon in a Small Lowland Stream (Sitka, Czech Republic): Structure and Distribution

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