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The hydrological context determines the beta-diversity of aerobic anoxygenic phototrophic bacteria in European Arctic seas but does not favor endemism.

Lehours AC, Jeanthon C - Front Microbiol (2015)

Bottom Line: A majority (>60%) of pufM sequences were affiliated to the Gammaproteobacteria reasserting that this class often represents the major component of the AAP bacterial community in oceanic regions.Two alphaproteobacterial groups dominate locally suggesting that they can constitute key players in this marine system transiently.Whereas we expected specific AAP bacterial populations in this peculiar and newly explored ecosystem, most pufM sequences were highly related to sequences retrieved elsewhere.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire Microorganismes: Génome et Environnement, Clermont Université, Université Blaise Pascal Clermont-Ferrand, France ; Laboratoire Microorganismes: Génome et Environnement, Centre National de la Recherche Scientifique, UMR 6023 Aubière, France.

ABSTRACT
Despite an increasing number of studies over the last 15 years, aerobic anoxygenic photoheterotrophic (AAP) bacteria remain a puzzling functional group in terms of physiology, metabolism, and ecology. To contribute to a better knowledge of their environmental distribution, the present study aims at analyzing their diversity and structure at the boundary between the Norwegian, Greenland, and Barents Seas. The polymorphism of a marker gene encoding a sub-unit of the photosynthetic apparatus (pufM gene) was analyzed and attempted to be related to environmental parameters. The Atlantic or Arctic origin of water masses had a strong impact on the AAP bacterial community structure whose populations mostly belonged to the Alpha- and Gammaproteobacteria. A majority (>60%) of pufM sequences were affiliated to the Gammaproteobacteria reasserting that this class often represents the major component of the AAP bacterial community in oceanic regions. Two alphaproteobacterial groups dominate locally suggesting that they can constitute key players in this marine system transiently. We found that temperature is a major determinant of alpha diversity of AAP bacteria in this marine biome with specific clades emerging locally according to the partitioning of water masses. Whereas we expected specific AAP bacterial populations in this peculiar and newly explored ecosystem, most pufM sequences were highly related to sequences retrieved elsewhere. This observation highlights that the studied area does not favor AAP bacteria endemism but also opens new questions about the truthfulness of biogeographical patterns and on the extent of AAP bacterial diversity.

No MeSH data available.


Alpha- and beta-diversity of AAP bacteria according to TTGE band patterns. (A) Principal component analysis performed using the relative intensity peaks of the TTGE bands. The groups identified (G1, G2, G3, and G4) were confirmed by ANOSIM statistics (data not shown). (B–F) Plots of the correlation between AAP richness and (B) salinity (psu), (D) Chla (μ g L−1), (F) temperature (°C) and between AAP diversity (expressed using the Shannon-Wiener index) and (C) salinity, (E) Chla, (G) temperature.
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Figure 2: Alpha- and beta-diversity of AAP bacteria according to TTGE band patterns. (A) Principal component analysis performed using the relative intensity peaks of the TTGE bands. The groups identified (G1, G2, G3, and G4) were confirmed by ANOSIM statistics (data not shown). (B–F) Plots of the correlation between AAP richness and (B) salinity (psu), (D) Chla (μ g L−1), (F) temperature (°C) and between AAP diversity (expressed using the Shannon-Wiener index) and (C) salinity, (E) Chla, (G) temperature.

Mentions: To determine the distribution of AAP bacterial populations, the polymorphism of a 245-bp region targeted on the pufM gene was analyzed by TTGE profiling. Among the 4 groups identified by PCA (Figure 2A), G1 included samples of Arctic-influenced waters, and G2 and G3 contained stations of the S/N and E/W transects, respectively. This may indicate very different environmental conditions, although such differences were not clearly reflected by the individual ancillary parameters (Table S1). Moreover, these parameters were locally highly variable with depth (see stations Z15 and M09 as examples, Table S1) without affecting the distribution of AAP bacterial populations.


The hydrological context determines the beta-diversity of aerobic anoxygenic phototrophic bacteria in European Arctic seas but does not favor endemism.

Lehours AC, Jeanthon C - Front Microbiol (2015)

Alpha- and beta-diversity of AAP bacteria according to TTGE band patterns. (A) Principal component analysis performed using the relative intensity peaks of the TTGE bands. The groups identified (G1, G2, G3, and G4) were confirmed by ANOSIM statistics (data not shown). (B–F) Plots of the correlation between AAP richness and (B) salinity (psu), (D) Chla (μ g L−1), (F) temperature (°C) and between AAP diversity (expressed using the Shannon-Wiener index) and (C) salinity, (E) Chla, (G) temperature.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4490794&req=5

Figure 2: Alpha- and beta-diversity of AAP bacteria according to TTGE band patterns. (A) Principal component analysis performed using the relative intensity peaks of the TTGE bands. The groups identified (G1, G2, G3, and G4) were confirmed by ANOSIM statistics (data not shown). (B–F) Plots of the correlation between AAP richness and (B) salinity (psu), (D) Chla (μ g L−1), (F) temperature (°C) and between AAP diversity (expressed using the Shannon-Wiener index) and (C) salinity, (E) Chla, (G) temperature.
Mentions: To determine the distribution of AAP bacterial populations, the polymorphism of a 245-bp region targeted on the pufM gene was analyzed by TTGE profiling. Among the 4 groups identified by PCA (Figure 2A), G1 included samples of Arctic-influenced waters, and G2 and G3 contained stations of the S/N and E/W transects, respectively. This may indicate very different environmental conditions, although such differences were not clearly reflected by the individual ancillary parameters (Table S1). Moreover, these parameters were locally highly variable with depth (see stations Z15 and M09 as examples, Table S1) without affecting the distribution of AAP bacterial populations.

Bottom Line: A majority (>60%) of pufM sequences were affiliated to the Gammaproteobacteria reasserting that this class often represents the major component of the AAP bacterial community in oceanic regions.Two alphaproteobacterial groups dominate locally suggesting that they can constitute key players in this marine system transiently.Whereas we expected specific AAP bacterial populations in this peculiar and newly explored ecosystem, most pufM sequences were highly related to sequences retrieved elsewhere.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire Microorganismes: Génome et Environnement, Clermont Université, Université Blaise Pascal Clermont-Ferrand, France ; Laboratoire Microorganismes: Génome et Environnement, Centre National de la Recherche Scientifique, UMR 6023 Aubière, France.

ABSTRACT
Despite an increasing number of studies over the last 15 years, aerobic anoxygenic photoheterotrophic (AAP) bacteria remain a puzzling functional group in terms of physiology, metabolism, and ecology. To contribute to a better knowledge of their environmental distribution, the present study aims at analyzing their diversity and structure at the boundary between the Norwegian, Greenland, and Barents Seas. The polymorphism of a marker gene encoding a sub-unit of the photosynthetic apparatus (pufM gene) was analyzed and attempted to be related to environmental parameters. The Atlantic or Arctic origin of water masses had a strong impact on the AAP bacterial community structure whose populations mostly belonged to the Alpha- and Gammaproteobacteria. A majority (>60%) of pufM sequences were affiliated to the Gammaproteobacteria reasserting that this class often represents the major component of the AAP bacterial community in oceanic regions. Two alphaproteobacterial groups dominate locally suggesting that they can constitute key players in this marine system transiently. We found that temperature is a major determinant of alpha diversity of AAP bacteria in this marine biome with specific clades emerging locally according to the partitioning of water masses. Whereas we expected specific AAP bacterial populations in this peculiar and newly explored ecosystem, most pufM sequences were highly related to sequences retrieved elsewhere. This observation highlights that the studied area does not favor AAP bacteria endemism but also opens new questions about the truthfulness of biogeographical patterns and on the extent of AAP bacterial diversity.

No MeSH data available.