versão impressa ISSN 0100-4042
MONTEIRO, Nilson Kobori et al. Chemical characterization of the gels produced by the diazotrophic bacteria Rhizobium tropici and Mesorhizobium sp.. Quím. Nova [online]. 2012, vol.35, n.4, pp. 705-708. ISSN 0100-4042. http://dx.doi.org/10.1590/S0100-40422012000400009.
The exopolysaccharides with characteristics of gel produced by Rhizobium tropici (EPSRT) and Mesorhizobium sp (EPSMR) are acidic heteropolysaccharide composed mainly of glucose and galactose in a molar ratio of 4:1 and 5:1 respectively, with traces of mannose (~ 1%). Chemical analysis showed the presence of uronic acid, pyruvate and acetyl-substituents in the structures of both polymers. Experiments of gel permeation chromatography and polyacrylamide gel electrophoresis showed that EPSRT and EPSMR are homogeneous molecules with low grade of polydispersity. The EPS were characterized using spectroscopic techniques of FT-IR, 1H and 13C-NMR.
Palavras-chave : acid exopolysaccharide; Rhizobium tropici; Mesorhizobium sp.