title: Trimethylated homoserine functions as the major compatible solute in the globally significant oceanic cyanobacterium Trichodesmium.
abstract: The oceanic N2-fixing cyanobacterium Trichodesmium spp. form extensive surface blooms and contribute significantly to marine carbon and nitrogen cycles in the oligotrophic subtropical and tropical oceans. Trichodesmium grows in salinities from 27 to 43 parts per thousand (ppt), yet its salt acclimation strategy remains enigmatic because the genome of Trichodesmium erythraeum strain IMS101 lacks all genes for the biosynthesis of any known compatible solute. Using NMR and liquid chromatography coupled to mass spectroscopy, we identified the main compatible solute in T. erythraeum strain IMS101 as the quaternary ammonium compound N,N,N-trimethyl homoserine (or homoserine betaine) and elucidated its biosynthetic pathway. The identification of this compatible solute explains how Trichodesmium spp. can thrive in the marine system at varying salinities and provides further insight into the diversity of microbial salt acclimation.
authors: Institut für Biowissenschaften, Pflanzenphysiologie, Universität Rostock, D-18059 Rostock, Germany.
authors: Nadin
authors: N
authors: Pade
authors: Institut für Chemie, Universität Rostock, D-18059 Rostock, Germany.|Leibniz-Institut für Katalyse, D-18059 Rostock, Germany.
authors: Dirk
authors: D
authors: Michalik
authors: Institut für Chemie, Universität Rostock, D-18059 Rostock, Germany.
authors: Wolfgang
authors: W
authors: Ruth
authors: Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290001, Israel.
authors: Natalia
authors: N
authors: Belkin
authors: Faculty of Biology, University of Freiburg, D-79104 Freiburg, Germany.
authors: Wolfgang R
authors: WR
authors: Hess
authors: Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290001, Israel.
authors: Ilana
authors: I
authors: Berman-Frank
authors: Institut für Biowissenschaften, Pflanzenphysiologie, Universität Rostock, D-18059 Rostock, Germany; martin.hagemann@uni-rostock.de.
authors: Martin
authors: M
authors: Hagemann
mesh_terms: D066241:Carbon-13 Magnetic Resonance Spectroscopy; D006714:Homoserine / Q000031:analogs & derivatives* / Q000378:metabolism*; D008745:Methylation; D066244:Proton Magnetic Resonance Spectroscopy; D055049:Salt Tolerance; D000072359:Trichodesmium / Q000378:metabolism*
chemical_list: D006714:Homoserine
keywords: compatible solute; cyanobacteria; salt stress