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Ecology and Distribution of Thaumarchaea in the Deep Hypolimnion of Lake Maggiore.

Coci M, Odermatt N, Salcher MM, Pernthaler J, Corno G - Archaea (2015)

Bottom Line: In order to reach a high resolution at the Thaumarchaea community level, the probe MGI-535 was specifically designed for this study and applied to fluorescence in situ hybridization and catalyzed reporter deposition (CARD-FISH) analysis.We then applied it to a fine analysis of diversity and relative abundance of AOA in the deepest layers of the oligotrophic Lake Maggiore, confirming previous published results of AOA presence, but showing differences in abundance and distribution within the water column without significant seasonal trends with respect to Bacteria.Furthermore, phylogenetic analysis of AOA clone libraries from deep lake water and from a lake tributary, River Maggia, suggested the riverine origin of AOA of the deep hypolimnion of the lake.

View Article: PubMed Central - PubMed

Affiliation: Microbial Ecology Group, CNR-Institute of Ecosystem Study, Largo Tonolli 50, 28922 Verbania, Italy ; Microb&Co, Association for Microbial Ecology, Viale XX Settembre 45, 95128 Catania, Italy.

ABSTRACT
Ammonia-oxidizing Archaea (AOA) play an important role in the oxidation of ammonia in terrestrial, marine, and geothermal habitats, as confirmed by a number of studies specifically focused on those environments. Much less is known about the ecological role of AOA in freshwaters. In order to reach a high resolution at the Thaumarchaea community level, the probe MGI-535 was specifically designed for this study and applied to fluorescence in situ hybridization and catalyzed reporter deposition (CARD-FISH) analysis. We then applied it to a fine analysis of diversity and relative abundance of AOA in the deepest layers of the oligotrophic Lake Maggiore, confirming previous published results of AOA presence, but showing differences in abundance and distribution within the water column without significant seasonal trends with respect to Bacteria. Furthermore, phylogenetic analysis of AOA clone libraries from deep lake water and from a lake tributary, River Maggia, suggested the riverine origin of AOA of the deep hypolimnion of the lake.

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Intra-annual vertical profiles of physical and chemical parameters at the Ghiffa pelagic station during 2011 (45°57′N, 3°46′W: 370 m depth). Temperature in °C (a), oxygen concentrations in mg L−1 (b), and chlorophyll a concentrations in μg L−1 (c) were measured every two weeks at intervals of 0.5 m. Concentrations of reactive phosphorous in μg L−1 (d), ammonium in μg L−1 (e), and nitrate in μg L−1 (f) were measured at 0, 5, 10, 20, 30, 50, 10, 150, 200, 250, 300, and 350 m depth.
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fig1: Intra-annual vertical profiles of physical and chemical parameters at the Ghiffa pelagic station during 2011 (45°57′N, 3°46′W: 370 m depth). Temperature in °C (a), oxygen concentrations in mg L−1 (b), and chlorophyll a concentrations in μg L−1 (c) were measured every two weeks at intervals of 0.5 m. Concentrations of reactive phosphorous in μg L−1 (d), ammonium in μg L−1 (e), and nitrate in μg L−1 (f) were measured at 0, 5, 10, 20, 30, 50, 10, 150, 200, 250, 300, and 350 m depth.

Mentions: Water temperature in Lake Maggiore was approximately 6.5°C in the whole water column during winter 2011. From March on, the temperature of the lake water column down to about 50 m depth increased to a maximum of 23°C at the surface in July and September (Figure 1(a)). The level of dissolved oxygen in the epilimnion varied throughout the year, with a maximum of 19.5 μg L−1 at the end of April, concomitant with the onset of temperature increase and a detected chlorophyll a (Chl a) maximum. In waters below 150 m depth, the oxygen concentration was constant at 6–8 μg L−1, indicating a full oxygenation of the deeper layers of the lake during the whole year (Figure 1(b)). Maxima of Chl a concentrations were detected between 2 and 10 m depths in April (13 μg L−1) and July (23 μg L−1) corresponding to spring and summer phytoplankton blooms. Below 20 m depth, Chl a concentrations constantly ranged between 0 and 2 μg L−1 (Figure 1(c)). Reactive phosphorus (RP) increased with depth and was depleted in the epilimnion between March and October. RP concentrations of 12–14 μg L−1 at 200 m depth and up to 19 μg L−1 at 350 m remained constant throughout the whole year (Figure 1(d)). Ammonium (N-NH4+) concentrations were close to instruments detection limits below 50 m depth (0–5 μg L−1) without any seasonal change, while there was a local maximum at 10 m depth at the beginning of May (Figure 1(e)). Nitrite (N-NO2) was always below the detection limit through the whole water column. Nitrate (N-NO3) had contrasting trends below 50 m, while in the epilimnion it decreased in summer. Mean annual nitrate concentrations at 200 and 350 m depths were around 830 μg L−1 (Figure 1(f)).


Ecology and Distribution of Thaumarchaea in the Deep Hypolimnion of Lake Maggiore.

Coci M, Odermatt N, Salcher MM, Pernthaler J, Corno G - Archaea (2015)

Intra-annual vertical profiles of physical and chemical parameters at the Ghiffa pelagic station during 2011 (45°57′N, 3°46′W: 370 m depth). Temperature in °C (a), oxygen concentrations in mg L−1 (b), and chlorophyll a concentrations in μg L−1 (c) were measured every two weeks at intervals of 0.5 m. Concentrations of reactive phosphorous in μg L−1 (d), ammonium in μg L−1 (e), and nitrate in μg L−1 (f) were measured at 0, 5, 10, 20, 30, 50, 10, 150, 200, 250, 300, and 350 m depth.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4561949&req=5

fig1: Intra-annual vertical profiles of physical and chemical parameters at the Ghiffa pelagic station during 2011 (45°57′N, 3°46′W: 370 m depth). Temperature in °C (a), oxygen concentrations in mg L−1 (b), and chlorophyll a concentrations in μg L−1 (c) were measured every two weeks at intervals of 0.5 m. Concentrations of reactive phosphorous in μg L−1 (d), ammonium in μg L−1 (e), and nitrate in μg L−1 (f) were measured at 0, 5, 10, 20, 30, 50, 10, 150, 200, 250, 300, and 350 m depth.
Mentions: Water temperature in Lake Maggiore was approximately 6.5°C in the whole water column during winter 2011. From March on, the temperature of the lake water column down to about 50 m depth increased to a maximum of 23°C at the surface in July and September (Figure 1(a)). The level of dissolved oxygen in the epilimnion varied throughout the year, with a maximum of 19.5 μg L−1 at the end of April, concomitant with the onset of temperature increase and a detected chlorophyll a (Chl a) maximum. In waters below 150 m depth, the oxygen concentration was constant at 6–8 μg L−1, indicating a full oxygenation of the deeper layers of the lake during the whole year (Figure 1(b)). Maxima of Chl a concentrations were detected between 2 and 10 m depths in April (13 μg L−1) and July (23 μg L−1) corresponding to spring and summer phytoplankton blooms. Below 20 m depth, Chl a concentrations constantly ranged between 0 and 2 μg L−1 (Figure 1(c)). Reactive phosphorus (RP) increased with depth and was depleted in the epilimnion between March and October. RP concentrations of 12–14 μg L−1 at 200 m depth and up to 19 μg L−1 at 350 m remained constant throughout the whole year (Figure 1(d)). Ammonium (N-NH4+) concentrations were close to instruments detection limits below 50 m depth (0–5 μg L−1) without any seasonal change, while there was a local maximum at 10 m depth at the beginning of May (Figure 1(e)). Nitrite (N-NO2) was always below the detection limit through the whole water column. Nitrate (N-NO3) had contrasting trends below 50 m, while in the epilimnion it decreased in summer. Mean annual nitrate concentrations at 200 and 350 m depths were around 830 μg L−1 (Figure 1(f)).

Bottom Line: In order to reach a high resolution at the Thaumarchaea community level, the probe MGI-535 was specifically designed for this study and applied to fluorescence in situ hybridization and catalyzed reporter deposition (CARD-FISH) analysis.We then applied it to a fine analysis of diversity and relative abundance of AOA in the deepest layers of the oligotrophic Lake Maggiore, confirming previous published results of AOA presence, but showing differences in abundance and distribution within the water column without significant seasonal trends with respect to Bacteria.Furthermore, phylogenetic analysis of AOA clone libraries from deep lake water and from a lake tributary, River Maggia, suggested the riverine origin of AOA of the deep hypolimnion of the lake.

View Article: PubMed Central - PubMed

Affiliation: Microbial Ecology Group, CNR-Institute of Ecosystem Study, Largo Tonolli 50, 28922 Verbania, Italy ; Microb&Co, Association for Microbial Ecology, Viale XX Settembre 45, 95128 Catania, Italy.

ABSTRACT
Ammonia-oxidizing Archaea (AOA) play an important role in the oxidation of ammonia in terrestrial, marine, and geothermal habitats, as confirmed by a number of studies specifically focused on those environments. Much less is known about the ecological role of AOA in freshwaters. In order to reach a high resolution at the Thaumarchaea community level, the probe MGI-535 was specifically designed for this study and applied to fluorescence in situ hybridization and catalyzed reporter deposition (CARD-FISH) analysis. We then applied it to a fine analysis of diversity and relative abundance of AOA in the deepest layers of the oligotrophic Lake Maggiore, confirming previous published results of AOA presence, but showing differences in abundance and distribution within the water column without significant seasonal trends with respect to Bacteria. Furthermore, phylogenetic analysis of AOA clone libraries from deep lake water and from a lake tributary, River Maggia, suggested the riverine origin of AOA of the deep hypolimnion of the lake.

Show MeSH