Structural elucidation of the exopolysaccharide produced by Pseudomonas veronii 2E

CAVALLERO, G.J; ; ; FERREIRA, M.L; CASABUONO, A.C ; RAMÍREZ, S.A; VULLO, D.L; COUTO, A.S

Buenos Aires

Congreso; III Glycoar; 2019

Sociedad Argentina de glicobiología

Most prokaryotic microorganisms grow in aggregated forms such as biofilms and flocs. Biofilms are complex system, composed of extracellular polymeric substances (EPS), in which exopolysaccharide represent the mayor biopolymer. The diversity in EPS structure found among bacteria provides a range of functional roles for microbial communities. Pseudomonas veronii 2E, an autochthonous bacterium isolated from sediments associated to the Reconquista River basin, produces EPS with Cd(II) binding properties, potentially useful for the biotreatment of metal polluted water. In this work, four exopolysaccharides were isolated and characterized from this biopolymer. Among them, the structure of the major acidic polysaccharide was completely elucidated. For this purpose, IR, MALDI-TOF and ESI-QTOF mass spectrometry analysis, 1D and 2D RMN spectroscopy and chemical treatments were used. The heteropolysaccharide consists in a  (1-4) glucan backbone highly substituted with a branching D-GlcAp (α 1-3)-L-Fucp disaccharide and terminal GlcNAc residues. The presence of this acidic disaccharide may explain the described metal binding ability of the EPS of P. veronii 2E and these structural features could provide an approach for potential bioremediation applications.