title: Surface properties and intracellular speciation revealed an original adaptive mechanism to arsenic in the acid mine drainage bio-indicator Euglena mutabilis.
abstract: Euglena mutabilis is a protist ubiquitously found in extreme environments such as acid mine drainages which are often rich in arsenic. The response of E. mutabilis to this metalloid was compared to that of Euglena gracilis, a protist not found in such environments. Membrane fatty acid composition, cell surface properties, arsenic accumulation kinetics, and intracellular arsenic speciation were determined. The results revealed a modification in fatty acid composition leading to an increased membrane fluidity in both Euglena species under sublethal arsenic concentrations exposure. This increased membrane fluidity correlated to an induced gliding motility observed in E. mutabilis in the presence of this metalloid but did not affect the flagellar dependent motility of E. gracilis. Moreover, when compared to E. gracilis, E. mutabilis showed highly hydrophobic cell surface properties and a higher tolerance to water-soluble arsenical compounds but not to hydrophobic ones. Finally, E. mutabilis showed a lower accumulation of total arsenic in the intracellular compartment and an absence of arsenic methylated species in contrast to E. gracilis. Taken together, our results revealed the existence of a specific arsenical response of E. mutabilis that may play a role in its hypertolerance to this toxic metalloid.
authors.affiliation: Département Microorganismes, Génomes, Environnement UMR7156 Université de Strasbourg/CNRS, Strasbourg, France. david.halter@gem.u-strasbg.fr
authors.forename: David
authors.initials: D
authors.lastname: Halter
authors.forename: Corinne
authors.initials: C
authors.lastname: Casiot
authors.forename: Hermann J
authors.initials: HJ
authors.lastname: Heipieper
authors.forename: Frédéric
authors.initials: F
authors.lastname: Plewniak
authors.forename: Marie
authors.initials: M
authors.lastname: Marchal
authors.forename: Stéphane
authors.initials: S
authors.lastname: Simon
authors.forename: Florence
authors.initials: F
authors.lastname: Arsène-Ploetze
authors.forename: Philippe N
authors.initials: PN
authors.lastname: Bertin
mesh_terms: D000222:Adaptation, Physiological; D001151:Arsenic / Q000633:toxicity*; D002462:Cell Membrane / Q000737:chemistry / Q000187:drug effects; D004361:Drug Tolerance; D005055:Euglena / Q000737:chemistry / Q000187:drug effects* / Q000502:physiology; D005227:Fatty Acids / Q000032:analysis; D057927:Hydrophobic and Hydrophilic Interactions; D008124:Locomotion; D008560:Membrane Fluidity / Q000187:drug effects; D012989:Soil Pollutants / Q000633:toxicity*; D013499:Surface Properties
chemical_list: D005227:Fatty Acids; D012989:Soil Pollutants; D001151:Arsenic