title: Identification of lipid and saccharide constituents of whole microalgal cells by ¹³C solid-state NMR.
abstract: Microalgae are unicellular organisms in which plasma membrane is protected by a complex cell wall. The chemical nature of this barrier is important not only for taxonomic identification, but also for interactions with exogenous molecules such as contaminants. In this work, we have studied freshwater (Chlamydomonas reinhardtii) and marine (Pavlova lutheri and Nannochloropsis oculata) microalgae with different cell wall characteristics. C. reinhardtii is covered by a network of fibrils and glycoproteins, while P. lutheri is protected by small cellulose scales, and the picoplankton N. oculata by a rigid cellulose wall. The objective of this work was to determine to what extent the different components of these microorganisms (proteins, carbohydrates, lipids) can be distinguished by ¹³C solid-state NMR with an emphasis on isolating the signature of their cell walls and membrane lipid constituents. By using NMR experiments which select rigid or mobile zones, as well as ¹³C-enriched microalgal cells, we improved the spectral resolution and simplified the highly crowded spectra. Interspecies differences in cell wall constituents, storage sugars and membrane lipid compositions were thus evidenced. Carbohydrates from the cell walls could be distinguished from those incorporated into sugar reserves or glycolipids. Lipids from the plasmalemma and organelle membranes and from storage vacuoles could also be identified. This work establishes a basis for a complete characterization of phytoplankton cells by solid-state NMR.
authors: Department of Chemistry, Université du Québec à Montréal, and Ressources Aquatiques Québec, P.O. Box 8888, Downtown Station, Montréal H3C 3P8, Canada.
authors: Alexandre A
authors: AA
authors: Arnold
authors: Department of Chemistry, Université du Québec à Montréal, and Ressources Aquatiques Québec, P.O. Box 8888, Downtown Station, Montréal H3C 3P8, Canada.
authors: Bertrand
authors: B
authors: Genard
authors: Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS, Université Paris Diderot and Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie-Curie, 75005 Paris, France.
authors: Francesca
authors: F
authors: Zito
authors: Institut des Sciences de la Mer, Université du Québec à Rimouski, and Ressources Aquatiques Québec, 310 Allée des Ursulines, Rimouski, Québec G5L 3A1, Canada.
authors: Réjean
authors: R
authors: Tremblay
authors: Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS, Université Paris Diderot and Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie-Curie, 75005 Paris, France.
authors: Dror E
authors: DE
authors: Warschawski
authors: Department of Chemistry, Université du Québec à Montréal, and Ressources Aquatiques Québec, P.O. Box 8888, Downtown Station, Montréal H3C 3P8, Canada. Electronic address: marcotte.isabelle@uqam.ca.
authors: Isabelle
authors: I
authors: Marcotte
mesh_terms: D002241:Carbohydrates / Q000032:analysis*; D066241:Carbon-13 Magnetic Resonance Spectroscopy / Q000379:methods*; D002473:Cell Wall / Q000737:chemistry; D005227:Fatty Acids / Q000032:analysis; D008055:Lipids / Q000032:analysis*; D058086:Microalgae / Q000737:chemistry*
chemical_list: D002241:Carbohydrates; D005227:Fatty Acids; D008055:Lipids
keywords: Cell surface; Dynamic filter; Membrane; Organelle; Phytoplankton; Storage