Archives of Microbiology

, Volume 170, Issue 5, pp 319–330

Uptake and synthesis of compatible solutes as microbial stress responses to high-osmolality environments

  • Bettina Kempf
  • E. Bremer

DOI: 10.1007/s002030050649

Cite this article as:
Kempf, B. & Bremer, E. Arch Microbiol (1998) 170: 319. doi:10.1007/s002030050649


All microorganisms possess a positive turgor, and maintenance of this outward-directed pressure is essential since it is generally considered as the driving force for cell expansion. Exposure of microorganisms to high-osmolality environments triggers rapid fluxes of cell water along the osmotic gradient out of the cell, thus causing a reduction in turgor and dehydration of the cytoplasm. To counteract the outflow of water, microorganisms increase their intracellular solute pool by amassing large amounts of organic osmolytes, the so-called compatible solutes. These osmoprotectants are highly congruous with the physiology of the cell and comprise a limited number of substances including the disaccharide trehalose, the amino acid proline, and the trimethylammonium compound glycine betaine. The intracellular amassing of compatible solutes as an adaptive strategy to high-osmolality environments is evolutionarily well-conserved in Bacteria, Archaea, and Eukarya. Furthermore, the nature of the osmolytes that are accumulated during water stress is maintained across the kingdoms, reflecting fundamental constraints on the kind of solutes that are compatible with macromolecular and cellular functions. Generally, compatible solutes can be amassed by microorganisms through uptake and synthesis. Here we summarise the molecular mechanisms of compatible solute accumulation in Escherichia coli and Bacillus subtilis, model organisms for the gram-negative and gram-positive branches of bacteria.

Key words OsmoregulationStress protectantsTrehaloseGlycine betaineK+ uptakeABCtransportersEffluxGene regulationEscherichia coliBacillus subtilis

Copyright information

© Springer-Verlag Berlin Heidelberg 1998

Authors and Affiliations

  • Bettina Kempf
    • 1
  • E. Bremer
    • 1
  1. 1.Philipps Universität Marburg, Fachbereich 17-Biologie, Laboratorium für Mikrobiologie, Karl-von-Frisch-Strasse, D-35032 Marburg, Germany Tel. +49-6421-281529; Fax +49-6421-288979 e-mail: bremer@mailer.uni-marburg.deDE