title: Profiling planktonic biomass using element-specific, multicomponent nuclear magnetic resonance spectroscopy.
abstract: Planktonic metabolism plays crucial roles in Earth's elemental cycles. Chemical speciation as well as elemental stoichiometry is important for advancing our understanding of planktonic roles in biogeochemical cycles. In this study, a multicomponent solid-state nuclear magnetic resonance (NMR) approach is proposed for chemical speciation of cellular components, using several advanced NMR techniques. Measurements by ssNMR were performed on (13)C and (15)N-labeled Euglena gracilis, a flagellated protist. 3D dipolar-assisted rotational resonance, double-cross-polarization (1)H-(13)C correlation spectroscopy, and (1)H-(13)C solid-state heteronuclear single quantum correlation spectroscopy successively allowed characterization of cellular components. These techniques were then applied to E. gracilis cultured in high and low ammonium media to demonstrate the power of this method for profiling and comparing cellular components. Cellular NMR spectra indicated that ammonium induced both paramylon degradation and amination. Arginine was stored as a nitrogen reserve and ammonium replaced by arginine catabolism via the arginine dihydrolase pathway. (15)N and (31)P cellular ssNMR indicated arginine and polyphosphate accumulation in E. gracilis, respectively. This chemical speciation technique will contribute to environmental research by providing detailed information on environmental chemical properties.
authors.affiliation: †RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan.|‡Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Komatsu
authors.affiliation: ‡Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan.
authors.forename: Toshiya
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: §Bruker Biospin K. K., 3-9, Moriya-cho, Kanagawa-ku, Yokohama, 221-0022, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Hatanaka
authors.affiliation: †RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan.|‡Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan.|∥Graduate School of Bioagricultural Sciences and School of Agricultural Sciences, Nagoya University, 1 Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Kikuchi
mesh_terms: D064751:Ammonium Compounds / Q000494:pharmacology; D018533:Biomass; D002247:Carbon Isotopes; D003470:Culture Media / Q000494:pharmacology; D004602:Elements; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009584:Nitrogen / Q000378:metabolism; D010933:Plankton / Q000187:drug effects / Q000378:metabolism*; D012815:Signal Processing, Computer-Assisted
chemical_list: D064751:Ammonium Compounds; D002247:Carbon Isotopes; D003470:Culture Media; D004602:Elements; D009584:Nitrogen