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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.


The capacity for substrate utilization using Biolog Ecoplates in the communities from Roskilde Fjord (A) and Great Belt (B). The absorbance values were normalized to the average well color development (AWCD) of the plate, and months scoring higher than the average well color (value of 1) is interpreted as the substrate being utilized. Each point represent the average of triplicate wells.
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Figure 5: The capacity for substrate utilization using Biolog Ecoplates in the communities from Roskilde Fjord (A) and Great Belt (B). The absorbance values were normalized to the average well color development (AWCD) of the plate, and months scoring higher than the average well color (value of 1) is interpreted as the substrate being utilized. Each point represent the average of triplicate wells.

Mentions: Extracellular enzyme activities varied over the year with average rates higher in RF than GB (Figure 4; Supplementary Figure S4). In both systems protease activities were on average 100-fold higher than the other enzymes (Figure 4). Most of the 31 different substrates were utilized on one or several occasions and varied over the year in both RF and GB (Figure 5). In RF, the utilization of six substrates (Glucose-phosphate, Glycerol phosphate, Hydroxybutyric acid, Phenylalanine, 2- and 4-Hydroxybenzoic Acid.) was never detected, while Tween 40 and Cellobiose were utilized on all occasions. In GB, utilization of three substrates (Glycerol phosphate, Phenylalanine and 2-Hydroxybenzoic acid) were not detected, while Itaconic acid were utilized on all occasions. Overall patterns in substrate use correlated to months (PERMANOVA, permutations = 999) with the months alone explaining R2 = 0.407 (p = 0.001) and R2 = 0.586 (p = 0.001) of the variance in RF and GB, respectively. However, the patterns of potential substrate utilization over the year were not significantly linked to the community composition of the total or active communities (Mantel test, 9999 permutations, p > 0.1 for all combinations tested).


Coupling Bacterioplankton Populations and Environment to Community Function in Coastal Temperate Waters
The capacity for substrate utilization using Biolog Ecoplates in the communities from Roskilde Fjord (A) and Great Belt (B). The absorbance values were normalized to the average well color development (AWCD) of the plate, and months scoring higher than the average well color (value of 1) is interpreted as the substrate being utilized. Each point represent the average of triplicate wells.
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Related In: Results  -  Collection

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

Figure 5: The capacity for substrate utilization using Biolog Ecoplates in the communities from Roskilde Fjord (A) and Great Belt (B). The absorbance values were normalized to the average well color development (AWCD) of the plate, and months scoring higher than the average well color (value of 1) is interpreted as the substrate being utilized. Each point represent the average of triplicate wells.
Mentions: Extracellular enzyme activities varied over the year with average rates higher in RF than GB (Figure 4; Supplementary Figure S4). In both systems protease activities were on average 100-fold higher than the other enzymes (Figure 4). Most of the 31 different substrates were utilized on one or several occasions and varied over the year in both RF and GB (Figure 5). In RF, the utilization of six substrates (Glucose-phosphate, Glycerol phosphate, Hydroxybutyric acid, Phenylalanine, 2- and 4-Hydroxybenzoic Acid.) was never detected, while Tween 40 and Cellobiose were utilized on all occasions. In GB, utilization of three substrates (Glycerol phosphate, Phenylalanine and 2-Hydroxybenzoic acid) were not detected, while Itaconic acid were utilized on all occasions. Overall patterns in substrate use correlated to months (PERMANOVA, permutations = 999) with the months alone explaining R2 = 0.407 (p = 0.001) and R2 = 0.586 (p = 0.001) of the variance in RF and GB, respectively. However, the patterns of potential substrate utilization over the year were not significantly linked to the community composition of the total or active communities (Mantel test, 9999 permutations, p > 0.1 for all combinations tested).

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.