title: Lipids as paleomarkers to constrain the marine nitrogen cycle.
abstract: Global climate is, in part, regulated by the effect of microbial processes on biogeochemical cycling. The nitrogen cycle, in particular, is driven by microorganisms responsible for the fixation and loss of nitrogen, and the reduction-oxidation transformations of bio-available nitrogen. Within marine systems, nitrogen availability is often the limiting factor in the growth of autotrophic organisms, intrinsically linking the nitrogen and carbon cycles. In order to elucidate the state of these cycles in the past, and help envisage present and future variability, it is essential to understand the specific microbial processes responsible for transforming bio-available nitrogen species. As most microorganisms are soft-bodied and seldom leave behind physical fossils in the sedimentary record, recalcitrant lipid biomarkers are used to unravel microbial processes in the geological past. This review emphasises the recent advances in marine nitrogen cycle lipid biomarkers, underlines the missing links still needed to fully elucidate past shifts in this biogeochemically-important cycle, and provides examples of biomarker applications in the geological past.
authors.affiliation: Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, and Utrecht University, Den Burg, P.O. Box 59 1790 AB, The Netherlands.|School of Civil Engineering and Geosciences, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, United Kingdom.
authors.forename: Darci
authors.initials: D
authors.lastname: Rush
authors.affiliation: Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, and Utrecht University, Den Burg, P.O. Box 59 1790 AB, The Netherlands.|Department of Earth Sciences, Faculty of Geosciences, Utrecht University, TA Utrecht, P.O. Box 80.121, 3508, The Netherlands.
authors.forename: Jaap S
authors.identifier: 0000-0002-8683-1854
authors.initials: JS
authors.lastname: Sinninghe Damsté
mesh_terms: D015415:Biomarkers; D002980:Climate; D000458:Cyanobacteria / Q000378:metabolism*; D058440:Denitrification / Q000502:physiology*; D008055:Lipids / Q000502:physiology*; D058465:Nitrification / Q000502:physiology*; D009584:Nitrogen / Q000378:metabolism; D009586:Nitrogen Fixation / Q000502:physiology*; D000072738:Nitrogen-Fixing Bacteria / Q000378:metabolism*; D010084:Oxidation-Reduction
chemical_list: D015415:Biomarkers; D008055:Lipids; D009584:Nitrogen