title: Comparison of the effect of salinity on the D/H ratio of fatty acids of heterotrophic and photoautotrophic microorganisms.
abstract: The core metabolism of microorganisms has a major influence on the hydrogen isotopic composition of their fatty acids. Heterotrophic microorganisms produce fatty acids with a deuterium to hydrogen (D/H) ratio either slightly depleted or enriched in D compared to the growth water, while photo- and chemoautotrophic microorganisms produce fatty acids which are heavily depleted in D. However, besides metabolism other biochemical and environmental factors (i.e. biosynthetic pathways, growth phase and temperature) have been shown to affect the D/H ratio of fatty acids, and it is necessary to evaluate the magnitude of these effects compared to that of metabolism. Here, we show that the effect of salinity on the D/H ratio of fatty acids depends on the core metabolism of the microorganism. While fatty acids of the photoautotroph Isochrysis galbana become more enriched in D with increasing salinity (enrichment of 30-40‰ over a range of 25 salinity units), no effect of salinity on the D/H ratio of fatty acids of the heterotrophic Pseudomonas str. LFY10 was observed ((ε)lipid/water of the C16:0 fatty acid of ~120‰ over a range of 10 salinity units). This can likely be explained by the relative contributions of different H and nicotinamide adenine dinucleotide phosphate sources during fatty acid biosynthesis.
authors.affiliation: NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, 1790 AB Den Burg, the Netherlands sandra.heinzelmann@nioz.nl.
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Heinzelmann
authors.affiliation: NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, 1790 AB Den Burg, the Netherlands.
authors.forename: David
authors.initials: D
authors.lastname: Chivall
authors.affiliation: NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, 1790 AB Den Burg, the Netherlands.
authors.forename: Daniela
authors.initials: D
authors.lastname: M'Boule
authors.affiliation: NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, 1790 AB Den Burg, the Netherlands.
authors.forename: Danielle
authors.initials: D
authors.lastname: Sinke-Schoen
authors.affiliation: NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, 1790 AB Den Burg, the Netherlands.
authors.forename: Laura
authors.initials: L
authors.lastname: Villanueva
authors.affiliation: NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, 1790 AB Den Burg, the Netherlands Utrecht University, Faculty of Geosciences, Department of Earth Sciences, Geochemistry, 3508 TA Utrecht, the Netherlands.
authors.forename: Jaap S Sinninghe
authors.initials: JS
authors.lastname: Damsté
authors.affiliation: NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, 1790 AB Den Burg, the Netherlands Utrecht University, Faculty of Geosciences, Department of Earth Sciences, Geochemistry, 3508 TA Utrecht, the Netherlands.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schouten
authors.affiliation: NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, 1790 AB Den Burg, the Netherlands.
authors.forename: Marcel T J
authors.initials: MT
authors.lastname: van der Meer
mesh_terms: D052818:Autotrophic Processes / Q000502:physiology; D003903:Deuterium; D005227:Fatty Acids / Q000096:biosynthesis / Q000737:chemistry*; D058087:Haptophyta / Q000378:metabolism*; D052836:Heterotrophic Processes / Q000502:physiology; D006859:Hydrogen; D008027:Light; D008055:Lipids / Q000096:biosynthesis; D009249:NADP / Q000378:metabolism; D011549:Pseudomonas / Q000378:metabolism*; D054712:Salinity; D014867:Water
chemical_list: D005227:Fatty Acids; D008055:Lipids; D014867:Water; D009249:NADP; D006859:Hydrogen; D003903:Deuterium
keywords: Isochrysis galbana; Pseudomonas; cultivation; deuterium; fatty acids; heterotrophs; hydrogen isotopes; metabolism; photoautotrophs; salinity