Chemical and Thermal Characterization of an exopolysaccharide from Lactiplantibacillus plantarum BAL-29-ITTG

Exopolysaccarides (EPS) are biopolymers, which can be produced by lactic acid bacteria. In this work an EPS from Lactiplantibacillus plantarum BAL-29-ITTG was characterized by 1H, 13C, COSY, TOCSY and HSQC nuclear magnetic resonance spectroscopy (NMR), infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and viscometry. Thermal analysis and viscometry results suggested that ESP had a high molecular weight with a branched structure; to determine its main monosaccharides, the experimental chemical shifts of hydrogens and carbons obtained by NMR were loaded and compared with the database in the online software CASPER: http://www.casper.organ.su.se./casper/ Results showed that at least eight monosaccharides are present as components of this EPS, the most likely monosaccharides identified were: b-D-glucopyranose 1-4 and 1-6 linked: →4)-b-D-Glc-(1→; →6)-b-D-Glc-(1→ and a-D -manose 1-3, 1-4 and 1-6 linked: →3)-a-D-Man-(1→; →4)-a-D-Man-(1→; →6)-a-D-Man-(1→, although, data from FTIR and NMR also suggest N-acetylated residues.