title: Synthesis, accumulation and hydrolysis of trehalose during growth of peanut rhizobia in hyperosmotic media.
abstract: We examined and compared the activities of synthetic and hydrolytic enzymes involved in trehalose metabolism, in three peanut rhizobia strains grown in control, hypersaline, and non-ionic hyperosmotic media. Results indicated that the effects of hyperosmolarity on the synthesis and the degradation of the disaccharide were diverse. In the salt-tolerant slow-growing strain Bradyrhizobium sp. ATCC 10317, we observed increased synthesis and accumulation of trehalose under hyperosmolarity imposed by either NaCl or PEG-8000. In the other two peanut rhizobia strains, the disaccharide level did not change under hypersalinity. In the salt-sensitive slow-growing strain Bradyrhizobium sp. USDA 3187, intracellular trehalose diminished in late stationary phase-cells grown with PEG, this reduction was accompanied by both an increased activity of synthetic enzymes and a decreased activity of trehalase. In the salt-tolerant fast-growing strain Rhizobium sp. TAL 1000, we also observed a reduction of intracellular trehalose under PEG-mediated growth, this decrease was early and transiently accompanied by an enhancement of trehalase activity, afterwards, the activity of synthetic enzymes augmented.
authors.affiliation: Department of Molecular Biology, National University of Río Cuarto, Córdoba, Argentina.
authors.forename: M S
authors.initials: MS
authors.lastname: Dardanelli
authors.forename: P S
authors.initials: PS
authors.lastname: González
authors.forename: M A
authors.initials: MA
authors.lastname: Bueno
authors.forename: N E
authors.initials: NE
authors.lastname: Ghittoni
mesh_terms: D010367:Arachis / Q000382:microbiology*; D020369:Bradyrhizobium / Q000201:enzymology / Q000378:metabolism*; D003470:Culture Media; D006868:Hydrolysis; D009994:Osmolar Concentration; D012231:Rhizobium / Q000201:enzymology / Q000378:metabolism*; D014198:Trehalase / Q000378:metabolism*; D014199:Trehalose / Q000378:metabolism*
chemical_list: D003470:Culture Media; D014199:Trehalose; D014198:Trehalase