Osmoadaptation mechanisms in prokaryotes: distribution of compatible solutes

• Published in: International microbiology Vol. 11; no. 3; pp. 151 - 162
• Main Authors: Empadinhas, Nuno, da Costa, Milton S
• Format: Journal Article
• Language: English
• Published: Switzerland Sociedad Española de Microbiología 01.09.2008
• Subjects: Adaptation, Physiological; Amino Acids - metabolism; Archaea - physiology; Archaeal Proteins - genetics; Archaeal Proteins - metabolism; Bacterial Physiological Phenomena; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Evolution, Molecular; Organophosphates - metabolism; osmoadaptation · osmoregulation · compatible solutes · trehalose synthesis · biosynthetic pathways · prokaryotic evolution; Osmolar Concentration; Polymers - metabolism; Sodium Chloride - metabolism; Trehalose - biosynthesis; Water-Electrolyte Balance
• ISSN: 1139-6709; 1618-1905
• DOI: 10.2436/20.1501.01.55

Microorganisms respond to osmotic stress mostly by accumulating compatible solutes, either by uptake from the medium or by de novo synthesis. These osmotically active molecules preserve the positive turgor pressure required for cell division. The diversity of compatible solutes is large but falls into a few major chemical categories; they are usually small organic molecules such as amino acids or their derivatives, and carbohydrates or their derivatives. Some are widely distributed in nature while others seem to be exclusively present in specific groups of organisms. This review discusses the diversity and distribution of known classes of compatible solutes found in prokaryotes as well as the increasing knowledge of the genes and pathways involved in their synthesis. The alternative roles of some archetypal compatible solutes not subject to osmoregulatory constraints are also discussed.