title: Identification of aquatically available carbon from algae through solution-state NMR of whole (13)C-labelled cells.
abstract: Green algae and cyanobacteria are primary producers with profound impact on food web functioning. Both represent key carbon sources and sinks in the aquatic environment, helping modulate the dissolved organic matter balance and representing a potential biofuel source. Underlying the impact of algae and cyanobacteria on an ecosystem level is their molecular composition. Herein, intact (13)C-labelled whole cell suspensions of Chlamydomonas reinhardtii, Chlorella vulgaris and Synechocystis were studied using a variety of 1D and 2D (1)H/(13)C solution-state nuclear magnetic resonance (NMR) spectroscopic experiments. Solution-state NMR spectroscopy of whole cell suspensions is particularly relevant as it identifies species that are mobile (dissolved or dynamic gels), 'aquatically available' and directly contribute to the aquatic carbon pool upon lysis, death or become a readily available food source on consumption. In this study, a wide range of metabolites and structural components were identified within the whole cell suspensions. In addition, significant differences in the lipid/triacylglyceride (TAG) content of green algae and cyanobacteria were confirmed. Mobile species in algae are quite different from those in abundance in 'classic' dissolved organic matter (DOM) indicating that if algae are major contributors to DOM, considerable selective preservation of minor components (e.g. sterols) or biotransformation would have to occur. Identifying the metabolites and dissolved components within algal cells by NMR permits future studies of carbon transfer between species and through the food chain, whilst providing a foundation to better understand the role of algae in the formation of DOM and the sequestration/transformation of carbon in aquatic environments.
authors.affiliation: Environmental NMR Centre, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.|Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Akhter
authors.affiliation: Environmental NMR Centre, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.|Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.
authors.forename: Rudraksha
authors.initials: R
authors.lastname: Dutta Majumdar
authors.affiliation: Environmental NMR Centre, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.|Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.
authors.forename: Blythe
authors.initials: B
authors.lastname: Fortier-McGill
authors.affiliation: Environmental NMR Centre, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.|Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.
authors.forename: Ronald
authors.initials: R
authors.lastname: Soong
authors.affiliation: Environmental NMR Centre, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.|Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.
authors.forename: Yalda
authors.initials: Y
authors.lastname: Liaghati-Mobarhan
authors.affiliation: Environmental NMR Centre, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.|Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.
authors.forename: Myrna
authors.initials: M
authors.lastname: Simpson
authors.affiliation: Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.
authors.forename: George
authors.initials: G
authors.lastname: Arhonditsis
authors.affiliation: Silantes GmbH, Gollierstr. 70 C, 80339, München, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schmidt
authors.affiliation: Silantes GmbH, Gollierstr. 70 C, 80339, München, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Heumann
authors.affiliation: Environmental NMR Centre, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada. andre.simpson@utoronto.ca.|Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada. andre.simpson@utoronto.ca.
authors.forename: André J
authors.initials: AJ
authors.lastname: Simpson
mesh_terms: D002247:Carbon Isotopes / Q000032:analysis* / Q000378:metabolism; D016825:Chlamydomonas reinhardtii / Q000737:chemistry* / Q000378:metabolism; D048408:Chlorella vulgaris / Q000737:chemistry* / Q000378:metabolism; D007553:Isotope Labeling; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D046939:Synechocystis / Q000737:chemistry* / Q000378:metabolism
chemical_list: D002247:Carbon Isotopes; D008055:Lipids
keywords: Algae; Dissolved organic matter; HMQC; Metabolomics; Solution-state NMR