Efecto de distintas condiciones de cultivo sobre el crecimiento y los oligoglucanos periplásmicos de dos Rhizobium spp simbiontes del maní.

MIGUEL A. BUENO; PAOLA S. GONZÁLEZ; MARIELA R. WOELKE; MARTA S. DARDANELLI; NORA E. GHITTONI

Uruguay

Congreso; Reuniones Latinoamericanas de Rhizobiología; 1994

ALAR

Two peanut Rhizobium spp were studied. Significant differnces between the strains were detected in the growth behavior and in the synthesis of periplasmic oligoglucans (OP). The strain ATCC 10317 showed patterns of growth characteristics of fast-growers, and was tolerant to 400 mM NaCl. When growing on a basal medium, cells synthetized OP of molecular size close to the medium OP nearly completely disappeared and they were replaced by the non reducing disaccharide trehalose. When disaccharides were the carbon sources, OP production was strongly diminished, concomitantly trehalose accumulation was observed. On the other hand, the strain USDA 3187 behaved as a slow-grower and was tolerant to 400 mM NaCl, above this salt concentration  the growth stopped completely. On a basal medium, cells synthetized four species of  OP, the main of them was identified as trehalose. When the strain grew with 100  mM NaCl, the content of trehalose was  slightly increased. Surprisingly, the strain was able to utilize disaccharides as carbon sources. Cells grown on media with either maltose or lactose, synthetized negligible quantities of OP and accumulated a reducing disaccharide.