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Coupling Bacterioplankton Populations and Environment to Community Function in Coastal Temperate Waters

View Article: PubMed Central - PubMed

ABSTRACT

Bacterioplankton play a key role in marine waters facilitating processes important for carbon cycling. However, the influence of specific bacterial populations and environmental conditions on bacterioplankton community performance remains unclear. The aim of the present study was to identify drivers of bacterioplankton community functions, taking into account the variability in community composition and environmental conditions over seasons, in two contrasting coastal systems. A Least Absolute Shrinkage and Selection Operator (LASSO) analysis of the biological and chemical data obtained from surface waters over a full year indicated that specific bacterial populations were linked to measured functions. Namely, Synechococcus (Cyanobacteria) was strongly correlated with protease activity. Both function and community composition showed seasonal variation. However, the pattern of substrate utilization capacity could not be directly linked to the community dynamics. The overall importance of dissolved organic matter (DOM) parameters in the LASSO models indicate that bacterioplankton respond to the present substrate landscape, with a particular importance of nitrogenous DOM. The identification of common drivers of bacterioplankton community functions in two different systems indicates that the drivers may be of broader relevance in coastal temperate waters.

No MeSH data available.


Bacterial abundance (BA), production (BP), and growth efficiency (BGE) in Roskilde Fjord (A) and Great Belt (B), respectively, over the season. Note the different scales for BA in (A) and (B). Error bars represent standard errors.
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Figure 3: Bacterial abundance (BA), production (BP), and growth efficiency (BGE) in Roskilde Fjord (A) and Great Belt (B), respectively, over the season. Note the different scales for BA in (A) and (B). Error bars represent standard errors.

Mentions: Bacterial abundance in RF was on average 4.0 ± 2.1 × 106 cells ml-1, while being roughly tenfold lower in GB (6.4 ± 2.7 × 105 cells ml-1; Figure 3; Supplementary Figure S3). BP in RF increased with Chl a during the spring bloom, followed by a second, larger peak in May, which coincided with maximum bacterial abundance. BGE increased on two occasions in RF with maxima in May (24 ± 2.9%) and September (39 ± 9.4%; Figure 3A). In GB, the production peaked concurrently with the spring bloom and again in August. However, in GB the growth efficiency was <4% during spring and early summer despite high BP, while in the fall the growth efficiency increased to a maximum value of 37 ± 11% following the largest peak in production (Figure 3B).


Coupling Bacterioplankton Populations and Environment to Community Function in Coastal Temperate Waters
Bacterial abundance (BA), production (BP), and growth efficiency (BGE) in Roskilde Fjord (A) and Great Belt (B), respectively, over the season. Note the different scales for BA in (A) and (B). Error bars represent standard errors.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5037133&req=5

Figure 3: Bacterial abundance (BA), production (BP), and growth efficiency (BGE) in Roskilde Fjord (A) and Great Belt (B), respectively, over the season. Note the different scales for BA in (A) and (B). Error bars represent standard errors.
Mentions: Bacterial abundance in RF was on average 4.0 ± 2.1 × 106 cells ml-1, while being roughly tenfold lower in GB (6.4 ± 2.7 × 105 cells ml-1; Figure 3; Supplementary Figure S3). BP in RF increased with Chl a during the spring bloom, followed by a second, larger peak in May, which coincided with maximum bacterial abundance. BGE increased on two occasions in RF with maxima in May (24 ± 2.9%) and September (39 ± 9.4%; Figure 3A). In GB, the production peaked concurrently with the spring bloom and again in August. However, in GB the growth efficiency was <4% during spring and early summer despite high BP, while in the fall the growth efficiency increased to a maximum value of 37 ± 11% following the largest peak in production (Figure 3B).

View Article: PubMed Central - PubMed

ABSTRACT

Bacterioplankton play a key role in marine waters facilitating processes important for carbon cycling. However, the influence of specific bacterial populations and environmental conditions on bacterioplankton community performance remains unclear. The aim of the present study was to identify drivers of bacterioplankton community functions, taking into account the variability in community composition and environmental conditions over seasons, in two contrasting coastal systems. A Least Absolute Shrinkage and Selection Operator (LASSO) analysis of the biological and chemical data obtained from surface waters over a full year indicated that specific bacterial populations were linked to measured functions. Namely, Synechococcus (Cyanobacteria) was strongly correlated with protease activity. Both function and community composition showed seasonal variation. However, the pattern of substrate utilization capacity could not be directly linked to the community dynamics. The overall importance of dissolved organic matter (DOM) parameters in the LASSO models indicate that bacterioplankton respond to the present substrate landscape, with a particular importance of nitrogenous DOM. The identification of common drivers of bacterioplankton community functions in two different systems indicates that the drivers may be of broader relevance in coastal temperate waters.

No MeSH data available.