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Closely related phytoplankton species produce similar suites of dissolved organic matter.

Becker JW, Berube PM, Follett CL, Waterbury JB, Chisholm SW, Delong EF, Repeta DJ - Front Microbiol (2014)

Bottom Line: Connections between DOMP features and the phylogenetic relatedness of these strains were identified on multiple levels of phylogenetic distance, suggesting that marine phytoplankton produce DOM that in part reflects its phylogenetic origin.Chemical information regarding the size and polarity ranges of features from defined biological sources was also obtained.Our findings reveal DOMP composition to be partially conserved among related phytoplankton species, and implicate marine DOM as a potential factor influencing microbial diversity in the sea by acting as a link between autotrophic and heterotrophic microbial community structures.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Woods Hole Oceanographic Institution Woods Hole, MA, USA ; Department of Civil and Environmental Engineering, Massachusetts Institute of Technology Cambridge, MA, USA.

ABSTRACT
Production of dissolved organic matter (DOM) by marine phytoplankton supplies the majority of organic substrate consumed by heterotrophic bacterioplankton in the sea. This production and subsequent consumption converts a vast quantity of carbon, nitrogen, and phosphorus between organic and inorganic forms, directly impacting global cycles of these biologically important elements. Details regarding the chemical composition of DOM produced by marine phytoplankton are sparse, and while often assumed, it is not currently known if phylogenetically distinct groups of marine phytoplankton release characteristic suites of DOM. To investigate the relationship between specific phytoplankton groups and the DOM they release, hydrophobic phytoplankton-derived dissolved organic matter (DOMP) from eight axenic strains was analyzed using high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS). Identification of DOM features derived from Prochlorococcus, Synechococcus, Thalassiosira, and Phaeodactylum revealed DOMP to be complex and highly strain dependent. Connections between DOMP features and the phylogenetic relatedness of these strains were identified on multiple levels of phylogenetic distance, suggesting that marine phytoplankton produce DOM that in part reflects its phylogenetic origin. Chemical information regarding the size and polarity ranges of features from defined biological sources was also obtained. Our findings reveal DOMP composition to be partially conserved among related phytoplankton species, and implicate marine DOM as a potential factor influencing microbial diversity in the sea by acting as a link between autotrophic and heterotrophic microbial community structures.

No MeSH data available.


Related in: MedlinePlus

Venn diagrams showing the degree to which triplicate cultures of representative phytoplankton strains share DOMP features. Each culture is represented by a circle, the area of which is proportional to the total number of features identified in that sample. The degree of overlap between circles is proportional to the number of shared features. Prochlorococcus str. MIT9313 replicates had the most variation of any strain tested (A), while P. tricornutum (CCMP632) replicates had the least variation (C). Synechococcus str. WH7803 replicates exhibited an average degree of variation indicative of most strains tested in this study (B). For more detailed information regarding replicate correlations, see Table 3.
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Figure 1: Venn diagrams showing the degree to which triplicate cultures of representative phytoplankton strains share DOMP features. Each culture is represented by a circle, the area of which is proportional to the total number of features identified in that sample. The degree of overlap between circles is proportional to the number of shared features. Prochlorococcus str. MIT9313 replicates had the most variation of any strain tested (A), while P. tricornutum (CCMP632) replicates had the least variation (C). Synechococcus str. WH7803 replicates exhibited an average degree of variation indicative of most strains tested in this study (B). For more detailed information regarding replicate correlations, see Table 3.

Mentions: HPLC-ESI-MS detected 577, 673, and 463 features in samples from strains MIT9313, MIT9301, and MED4, respectively. Purity broth tests revealed subsequent heterotrophic contamination in one of the MED4 replicate cultures; therefore this sample was removed from all analyses (see N/A in Table 1). Approximately 40% of the features associated with each Prochlorococcus strain were detected in all replicates of that strain (Table 1). MIT9313 replicates had the least agreement of all the strains in this study (Figure 1A). Prochlorococcus-derived DOMP generally consisted of small, non-polar material, with the majority of features detected between 200–500 m/z and 20–50 min, when the mobile phase composition was between 51 and 100% methanol (Figure 2).


Closely related phytoplankton species produce similar suites of dissolved organic matter.

Becker JW, Berube PM, Follett CL, Waterbury JB, Chisholm SW, Delong EF, Repeta DJ - Front Microbiol (2014)

Venn diagrams showing the degree to which triplicate cultures of representative phytoplankton strains share DOMP features. Each culture is represented by a circle, the area of which is proportional to the total number of features identified in that sample. The degree of overlap between circles is proportional to the number of shared features. Prochlorococcus str. MIT9313 replicates had the most variation of any strain tested (A), while P. tricornutum (CCMP632) replicates had the least variation (C). Synechococcus str. WH7803 replicates exhibited an average degree of variation indicative of most strains tested in this study (B). For more detailed information regarding replicate correlations, see Table 3.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3975126&req=5

Figure 1: Venn diagrams showing the degree to which triplicate cultures of representative phytoplankton strains share DOMP features. Each culture is represented by a circle, the area of which is proportional to the total number of features identified in that sample. The degree of overlap between circles is proportional to the number of shared features. Prochlorococcus str. MIT9313 replicates had the most variation of any strain tested (A), while P. tricornutum (CCMP632) replicates had the least variation (C). Synechococcus str. WH7803 replicates exhibited an average degree of variation indicative of most strains tested in this study (B). For more detailed information regarding replicate correlations, see Table 3.
Mentions: HPLC-ESI-MS detected 577, 673, and 463 features in samples from strains MIT9313, MIT9301, and MED4, respectively. Purity broth tests revealed subsequent heterotrophic contamination in one of the MED4 replicate cultures; therefore this sample was removed from all analyses (see N/A in Table 1). Approximately 40% of the features associated with each Prochlorococcus strain were detected in all replicates of that strain (Table 1). MIT9313 replicates had the least agreement of all the strains in this study (Figure 1A). Prochlorococcus-derived DOMP generally consisted of small, non-polar material, with the majority of features detected between 200–500 m/z and 20–50 min, when the mobile phase composition was between 51 and 100% methanol (Figure 2).

Bottom Line: Connections between DOMP features and the phylogenetic relatedness of these strains were identified on multiple levels of phylogenetic distance, suggesting that marine phytoplankton produce DOM that in part reflects its phylogenetic origin.Chemical information regarding the size and polarity ranges of features from defined biological sources was also obtained.Our findings reveal DOMP composition to be partially conserved among related phytoplankton species, and implicate marine DOM as a potential factor influencing microbial diversity in the sea by acting as a link between autotrophic and heterotrophic microbial community structures.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Woods Hole Oceanographic Institution Woods Hole, MA, USA ; Department of Civil and Environmental Engineering, Massachusetts Institute of Technology Cambridge, MA, USA.

ABSTRACT
Production of dissolved organic matter (DOM) by marine phytoplankton supplies the majority of organic substrate consumed by heterotrophic bacterioplankton in the sea. This production and subsequent consumption converts a vast quantity of carbon, nitrogen, and phosphorus between organic and inorganic forms, directly impacting global cycles of these biologically important elements. Details regarding the chemical composition of DOM produced by marine phytoplankton are sparse, and while often assumed, it is not currently known if phylogenetically distinct groups of marine phytoplankton release characteristic suites of DOM. To investigate the relationship between specific phytoplankton groups and the DOM they release, hydrophobic phytoplankton-derived dissolved organic matter (DOMP) from eight axenic strains was analyzed using high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS). Identification of DOM features derived from Prochlorococcus, Synechococcus, Thalassiosira, and Phaeodactylum revealed DOMP to be complex and highly strain dependent. Connections between DOMP features and the phylogenetic relatedness of these strains were identified on multiple levels of phylogenetic distance, suggesting that marine phytoplankton produce DOM that in part reflects its phylogenetic origin. Chemical information regarding the size and polarity ranges of features from defined biological sources was also obtained. Our findings reveal DOMP composition to be partially conserved among related phytoplankton species, and implicate marine DOM as a potential factor influencing microbial diversity in the sea by acting as a link between autotrophic and heterotrophic microbial community structures.

No MeSH data available.


Related in: MedlinePlus