Showing papers by "Erwin A. Galinski published in 1996"
TL;DR: This is the first study demonstrating a principal role for the de novo-synthesized polyol mannitol in osmoadaptation of a heterotrophic eubacterium.
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.
108 citations
TL;DR: Only species belonging to the genus Vibrio were able to synthesize the compatible solute ectoine de novo, and external supply of osmolytes improved both growth and salt tolerance.
Abstract: Marine luminescent bacteria of the genera Vibrio and Photobacterium as well as Photorhabdus (Xenorhabdus) luminescens, an enterobacterium mutualistically associated with insect pathogenic soil nematodes, display different levels of salt tolerance when grown on nutrient broth medium (5% w/v NaCl for marine species and 3% w/v for Prb. luminescens). Osmolytes (compatible solutes) synthesized and/or accumulated for haloadaptation were identified using HPLC techniques and 13C-NMR spectroscopy. All species investigated in this study accumulated betaine and ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidine carboxylic acid) from the medium under elevated osmotic conditions. External supply of osmolytes improved both growth and salt tolerance. Only species belonging to the genus Vibrio were able to synthesize the compatible solute ectoine de novo. Glutamate also participated in osmoadaptation while trehalose was only found in V. fischeri species. In Prb. luminescens 13C-NMR spectroscopy also revealed the presence of choline when grown on complex medium.
13 citations