Project description:Small, biologically produced, organic molecules called metabolites play key roles in microbial systems where they directly mediate exchanges of nutrients, energy, and information. However, the study of dissolved polar metabolites in seawater and other environmental matrices has been hampered by analytical challenges including high inorganic ion concentrations, low analyte concentrations, and high chemical diversity. Here we show that a cation-exchange solid phase extraction (CX-SPE) sample preparation approach separates positively charged and zwitterionic metabolites from seawater and freshwater samples, allowing their analysis by liquid chromatography-mass spectrometry (LC-MS). We successfully extracted 69 known compounds from an in-house compound collection and evaluated the performance of the method by establishing extraction efficiencies and limits of detection (pM to low nM range) for these compounds. CX-SPE extracted a range of compounds including amino acids and compatible solutes, resulted in very low matrix effects, and performed robustly across large variations in salinity and dissolved organic matter (DOM) concentration. We compared CX-SPE to an established solid phase extraction procedure (PPL-SPE) and demonstrate that these two methods extract fundamentally different fractions of the dissolved metabolite pool with CX-SPE extracting compounds that are on average smaller and more polar. We use CX-SPE to analyze four environmental samples from distinct aquatic biomes, producing some of the first CX-SPE dissolved metabolomes. Quantified compounds ranged in concentration from 0.0093 nM to 49 nM and were composed primarily of amino acids (0.15 – 16 nM) and compatible solutes such as TMAO (0.89 – 49 nM) and glycine betaine (2.8 – 5.2 nM).
Project description:16s RNA gene sequencing data from seawater, bed sediment and steel corrosion samples from Shoreham Harbour, UK, collected to allow bacterial species comparisons between microbially influenced corrosion, the surrounding seawater, and the sea bed sediment at the seafloor and 50cm depth below seafloor.
Project description:<p>One of the major bottlenecks in describing marine ecosystems is characterizing the metabolome of seawater, as salt prevents metabolite analysis. We present SeaMet, a method that can detect hundreds of metabolites in less than one ml of seawater and quantifies them down to nano-molar levels using gas chromatography-mass spectrometry. Our method provides a major advance in marine metabolomics by enabling the unbiased analysis of primary metabolites across saltwater habitats. </p><p><br></p><p>Cell culture sampling is reported in the current study.</p><p>Method development is reported in <a href="https://www.ebi.ac.uk/metabolights/MTBLS826" target="_blank">MTBLS826</a></p><p>The effect of salt and water on metabolite detection is reported in <a href="https://www.ebi.ac.uk/metabolights/MTBLS839" target="_blank">MTBLS839</a></p><p>Environmental sampling is reported in <a href="https://www.ebi.ac.uk/metabolights/MTBLS844" target="_blank">MTBLS844</a></p><p>Method quantification is reported in <a href="https://www.ebi.ac.uk/metabolights/MTBLS848" target="_blank">MTBLS848</a></p><p>Solid phase extraction is reported in <a href="https://www.ebi.ac.uk/metabolights/MTBLS849" target="_blank">MTBLS849</a></p>