Halophilic bacteria use a variety of osmoregulatory methods, such as the accumulation of one or more compatible solutes. The wide diversity of compounds that can act as compatible solute complicates the task of understanding the different strategies that halophilic bacteria use to cope with salt. This is specially challenging when attempting to go beyond the pathway that produces a certain comp...

Abiotic stresses collectively are responsible for crop losses worldwide. Among these, drought and salinity are the most destructive. Different strategies have been proposed for management of these stresses. Being a complex trait, conventional breeding approaches have resulted in less success. Biotechnology has emerged as an additional and novel tool for deciphering the mechanism behind these st...

The compatible solute mannosylglucosylglycerate (MGG), recently identified in Petrotoga miotherma, also accumulates in Petrotoga mobilis in response to hyperosmotic conditions and supraoptimal growth temperatures. Two functionally connected genes encoding a glucosyl-3-phosphoglycerate synthase (GpgS) and an unknown glycosyltransferase (gene Pmob_1143), which we functionally characterized as a m...

Diglycerol phosphate accumulates under salt stress in the archaeon Archaeoglobus fulgidus (L. O. Martins, R. Huber, H. Huber, K. O. Stetter, M. S. da Costa, and H. Santos, Appl. Environ. Microbiol. 63:896-902, 1997). This solute was purified after extraction from the cell biomass. In addition, the optically active and the optically inactive (racemic) forms of the compound were synthesized, and ...

A novel gas chromatography-mass spectrometry method for analyzing sulfonium compounds as their S-demethylated silyl derivatives has clarified the origin of 5-dimethylsulfoniopentanoate. This compound, previously reported from flowers of Diplotaxis tenuifolia (L.) DC. (Cruciferae), is generated from glucoerucin during treatment with hot 6 N HCl. Glucoerucin is the characteristic glucosinolate of...

Proline transporters (ProTs) mediate transport of the compatible solutes Pro, glycine betaine, and the stress-induced compound gamma-aminobutyric acid. A new member of this gene family, AtProT3, was isolated from Arabidopsis (Arabidopsis thaliana), and its properties were compared to AtProT1 and AtProT2. Transient expression of fusions of AtProT and the green fluorescent protein in tobacco (Nic...

The compatible solute 1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine) acts in microorganisms as an osmotic counterweight against halostress and has attracted commercial attention as a protecting agent. Its production and application are restricted by the drawbacks of the discontinuous harvesting procedure involving salt shocks, which reduces volumetric yield, increases reactor...

By using natural-abundance (13)C-nuclear magnetic resonance spectroscopy and high-performance liquid chromatography (HPLC) analysis we have investigated the types of compatible solutes that are synthesized de novo in a variety of Bacillus species under high-osmolality growth conditions. Five different patterns of compatible solute production were found among the 13 Bacillus species we studied. ...

The effects of salinity and growth temperature on the accumulation of intracellular organic solutes were examined by nuclear magnetic resonance spectroscopy (NMR) in Thermococcus litoralis, Thermococcus celer, Thermococcus stetteri, and Thermococcus zilligii (strain AN1). In addition, the effects of growth stage and composition of the medium were studied in T. litoralis. A novel compound identi...

The three proline transporters of Arabidopsis thaliana (AtProTs) transport the compatible solutes proline and glycine betaine and the stress-induced compound γ-aminobutyric acid when expressed in heterologous systems. The aim of the present study was to show transport and physiological relevance of these three AtProTs in planta. Using single, double, and triple knockout mutants and AtProT-overe...