Synthesis, accumulation, and hydrolysis of trehalose during growth of peanut rhizobia in hyperosmotic media.

MARTA S. DARDANELLI; PAOLA S. GONZÁLEZ; M.A BUENO; N.E GHITTONI

Journal basic of Microbiology

Wiley-VCH Verlag Gmbh & Co, KGaA

Lugar: Alemania; Año: 2000 vol. 40 p. 149 - 156

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 hyperomotic media. Results indicated that the effects of hiperosmolarity 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 shyntetic enzymes augmented.