title: Mannitol, a novel bacterial compatible solute in Pseudomonas putida S12.
abstract: The aim of this study was to identify the compatible solutes accumulated by Pseudomonas putida S12 subjected to osmotic stress. In response to reduced water activity, P. putida S12 accumulated Nalpha-acetylglutaminylglutamine amide (NAGGN) simultaneously with a novel compatible solute identified as mannitol (using 13C- and 1H-nuclear magnetic resonance, liquid chromatography-mass spectroscopy and high-performance liquid chromatography methods) to maximum concentrations of 74 and 258 micromol g (dry weight) of cells(-1), respectively. The intracellular amounts of each solute varied with both the type and amount of osmolyte applied to induce osmotic stress in the medium. Both solutes were synthesized de novo. Addition of betaine to the medium resulted in accumulation of this compound and depletion of both NAGGN and mannitol. Mannitol and NAGGN were accumulated when sucrose instead of salts was used to reduce the medium water activity. Furthermore, both compatible solutes were accumulated when glucose was substituted by other carbon sources. However, the intracellular quantities of mannitol decreased when fructose, succinate, or lactate were applied as a carbon source. Mannitol was also raised to high intracellular concentrations by other salt-stressed Pseudomonas putida strains. This is the first study demonstrating a principal role for the de novo-synthesized polyol mannitol in osmoadaptation of a heterotrophic eubacterium.
authors.affiliation: Division of Industrial Microbiology, Department of Food Science, Wageningen Agricultural University, The Netherlands. E.P.W.KETS@ATO.DLO.NL.
authors.forename: E P
authors.initials: EP
authors.lastname: Kets
authors.forename: E A
authors.initials: EA
authors.lastname: Galinski
authors.forename: M
authors.initials: M
authors.lastname: de Wit
authors.forename: J A
authors.initials: JA
authors.lastname: de Bont
authors.forename: H J
authors.initials: HJ
authors.lastname: Heipieper
mesh_terms: D001622:Betaine / Q000378:metabolism / Q000494:pharmacology; D002264:Carboxylic Acids / Q000378:metabolism; D003470:Culture Media; D004151:Dipeptides / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism; D006601:Hexoses / Q000378:metabolism; D008353:Mannitol / Q000378:metabolism*; D009997:Osmotic Pressure; D011189:Potassium Chloride / Q000494:pharmacology; D011549:Pseudomonas / Q000254:growth & development / Q000378:metabolism; D016958:Pseudomonas putida / Q000254:growth & development / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology; D013431:Sulfates / Q000494:pharmacology
chemical_list: D002264:Carboxylic Acids; D003470:Culture Media; D004151:Dipeptides; D006601:Hexoses; D013431:Sulfates; C012036:sodium sulfate; C060785:N-acetylglutaminylglutamine amide; C031512:potassium sulfate; D018698:Glutamic Acid; D008353:Mannitol; D001622:Betaine; D012965:Sodium Chloride; D011189:Potassium Chloride