title: Release of ecologically relevant metabolites by the cyanobacterium Synechococcus elongates CCMP 1631.
abstract: Photoautotrophic plankton in the surface ocean release organic compounds that fuel secondary production by heterotrophic bacteria. Here we show that an abundant marine cyanobacterium, Synechococcus elongatus, contributes a variety of nitrogen-rich and sulfur-containing compounds to dissolved organic matter. A combination of targeted and untargeted metabolomics and genomic tools was used to characterize the intracellular and extracellular metabolites of S. elongatus. Aromatic compounds, such as 4-hydroxybenzoic acid and phenylalanine, as well as nucleosides (e.g. thymidine, 5'-methylthioadenosine, xanthosine), the organosulfur compound 3-mercaptopropionate, and the plant auxin indole 3-acetic acid, were released by S. elongatus at multiple time points during its growth. Further, the amino acid kynurenine was found to accumulate in the media even though it was not present in the predicted metabolome of S. elongatus. This indicates that some metabolites, including those not predicted by an organism's genome, are likely excreted into the environment as waste; however, these molecules may have broader ecological relevance if they are labile to nearby microbes. The compounds described herein provide excellent targets for quantitative analysis in field settings to assess the source and lability of dissolved organic matter in situ.
authors.affiliation: Department of Marine Chemistry & Geochemistry, Woods Hole Oceanographic Institution, 360 Woods Hole Rd. MS#4, Woods Hole, MA, 02543, USA.
authors.forename: Cara L
authors.initials: CL
authors.lastname: Fiore
authors.affiliation: Department of Marine Chemistry & Geochemistry, Woods Hole Oceanographic Institution, 360 Woods Hole Rd. MS#4, Woods Hole, MA, 02543, USA.
authors.forename: Krista
authors.initials: K
authors.lastname: Longnecker
authors.affiliation: Department of Marine Chemistry & Geochemistry, Woods Hole Oceanographic Institution, 360 Woods Hole Rd. MS#4, Woods Hole, MA, 02543, USA.
authors.forename: Melissa C
authors.initials: MC
authors.lastname: Kido Soule
authors.affiliation: Department of Marine Chemistry & Geochemistry, Woods Hole Oceanographic Institution, 360 Woods Hole Rd. MS#4, Woods Hole, MA, 02543, USA.
authors.forename: Elizabeth B
authors.initials: EB
authors.lastname: Kujawinski
mesh_terms: D015097:3-Mercaptopropionic Acid / Q000378:metabolism; D003839:Deoxyadenosines / Q000378:metabolism; D004463:Ecology; D052836:Heterotrophic Processes; D007210:Indoleacetic Acids / Q000378:metabolism; D007737:Kynurenine / Q000378:metabolism; D055442:Metabolome; D055432:Metabolomics; D017672:Nitrogen Compounds / Q000378:metabolism*; D009705:Nucleosides / Q000378:metabolism; D010226:Parabens / Q000378:metabolism; D010649:Phenylalanine / Q000378:metabolism; D010933:Plankton / Q000378:metabolism; D013457:Sulfur Compounds / Q000378:metabolism*; D046940:Synechococcus / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D013872:Thionucleosides / Q000378:metabolism
chemical_list: D003839:Deoxyadenosines; D007210:Indoleacetic Acids; D017672:Nitrogen Compounds; D009705:Nucleosides; D010226:Parabens; D013457:Sulfur Compounds; D013872:Thionucleosides; D007737:Kynurenine; D010649:Phenylalanine; C008500:5'-methylthioadenosine; C030737:indoleacetic acid; D015097:3-Mercaptopropionic Acid; C038193:4-hydroxybenzoic acid