Trehalose and trehalase in the hypersaline adaptation of penut rhizobia

GHITTONI NORA; BUENO MIGUEL; DARDANELLI MARTA; GONZÁLEZ PAOLA S.

vANCOUVER, BC

Congreso; AMERICAN SOCIETY OF PLANT PHYSIOLOGISTS; 1996

The sensitivity of symbiotic rhizobia to environmental osmotic conditions could affect the productivity of useful legume crops, we investigated the adaptation to hyperosmotic stress in some peanut inoculants. Under hypersalinit fast-growers increased the cellular content of trehalose, regardless of the carbon source, slow-growers also increased the accumulation of the disaccharide when cultured with mannitol. (Ghittoni & Bueno, Symbiosis, 1996). The activity of the enzyme was determined. Periplasmic trehalase was purified about 6-fold. It had a pH optimum between 6.3 and 7.0, and a temperature optimum 60 C.This results suggests that decreased degradation of trehalase in the periplasmic space could be one of the responsible factors for the disaccharide accumulation in Rhizobium sp TAL 1000 under hypersaline stress.