Physiological response of two peanut rhizobia strain to acid pH

TAURIAN, T.; CASTRO, S.; FABRA, A.

SYMBIOSIS

SPRINGER

Lugar: Berlin; Año: 1998 vol. 24 p. 327 - 336

0334-5114

Soil acidity is a stress factor that negatively affects the persistence of Rhizobium strains and the nodulation and nitrogen fixation in legumes. To identify peanut symbiont acid-tolerant strains we tested the ability of Bradyrhizobium sp USDA3187 and Bradyrhizobium sp TT001 (isolated from nodules of peanut) to growth at pH5 in unbuffered broth medium . Only Bradyrhizobium sp TT001 grew at this pH and tolerance to this condition was not related with the synthesis of polyamines, lipopolysaccharides or with the production of extracellular polysaccharides. Cells of TT001 were markedly resistant to the effects of crystal violet and was not affected by pH5. These results suggest that the outer membrane structure could be involved in pH tolerance