title: Influence of osmotic stress on desiccation and irradiation tolerance of (hyper)-thermophilic microorganisms.
abstract: This study examined the influence of prior salt adaptation on the survival rate of (hyper)-thermophilic bacteria and archaea after desiccation and UV or ionizing irradiation treatment. Survival rates after desiccation of Hydrogenothermus marinus and Archaeoglobus fulgidus increased considerably when the cells were cultivated at higher salt concentrations before drying. By doubling the concentration of NaCl, a 30 times higher survival rate of H. marinus after desiccation was observed. Under salt stress, the compatible solute diglycerol phosphate in A. fulgidus and glucosylglycerate in H. marinus accumulated in the cytoplasm. Several different compatible solutes were added as protectants to A. fulgidus and H. marinus before desiccation treatment. Some of these had similar effects as intracellularly produced compatible solutes. The survival rates of H. marinus and A. fulgidus after exposure to UV-C (254 nm) or ionizing X-ray/gamma radiation were irrespective of the salt-induced synthesis or the addition of compatible solutes.
authors.affiliation: Institute of Aerospace Medicine, Radiation Biology Division, German Aerospace Center (DLR e.V.), Linder Höhe, 51147, Cologne, Germany. kristina.beblo@dlr.de.
authors.forename: Kristina
authors.identifier: http://orcid.org/0000-0002-4834-7121
authors.initials: K
authors.lastname: Beblo-Vranesevic
authors.affiliation: Institute of Microbiology and Biotechnology, Rheinische Friedrich-Wilhelms University, Bonn, Germany.
authors.forename: Erwin A
authors.initials: EA
authors.lastname: Galinski
authors.affiliation: Faculty of Biology and Preclinical Medicine, Center for Electron Microscopy, University Regensburg, Regensburg, Germany.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Rachel
authors.affiliation: Faculty of Biology and Preclinical Medicine, Institute for Microbiology and Archaea Center, University of Regensburg, Regensburg, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Huber
authors.affiliation: Institute of Aerospace Medicine, Radiation Biology Division, German Aerospace Center (DLR e.V.), Linder Höhe, 51147, Cologne, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Rettberg
mesh_terms: D019611:Archaeoglobus fulgidus / Q000737:chemistry / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects*; D001419:Bacteria / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D003890:Desiccation; D005994:Glycerophosphates / Q000494:pharmacology; D009997:Osmotic Pressure; D011839:Radiation, Ionizing; D055049:Salt Tolerance; D012965:Sodium Chloride / Q000378:metabolism
chemical_list: D005994:Glycerophosphates; C409185:diglycerol phosphate; D012965:Sodium Chloride
keywords: (Hyper)-thermophiles; Compatible solutes; Desiccation; Survival