Exopolysaccharide of Leuconostoc pseudomesenteroides strain B367: Production and characterization

Several members of lactic acid bacteria (LAB) are known to have the ability to produce exopolysaccharides (EPS) for industrial applications. The limited information on the uniqueness of EPS produced by LAB needs to be overcome by integrative compound profiling. This study aims to investigate the exopolysaccharide production and characterization of Leuconostoc pseudomesenteroides B367. The bacterial strain was cultivated in MRS-based media consisting of different carbon sources, i.e., glucose and sucrose, at the concentration of 10% to understand the requirement for high amounts of EPS production. The precipitation method was applied to separate the biomass of microbial cells and metabolite containing the EPS. A large molecule (>12.5 kDa) was obtained by applying the membrane dialysis. The EPS obtained in this study was then further characterized for the infrared spectra and the morphological structures. We confirmed in this study that the carbon source type affects the growth of strain B367 as well as the EPS production. Sucrose doubles the EPS production (9.2 g/L dried EPS) compared to the glucose-based medium (4.5 g/L dried EPS). The scanning microscopic observation confirmed the irregular porous surface of EPS derived from the bacterial strain. The FTIR analysis demonstrated different profiles represented by the peaks of infrared spectra of EPS obtained through glucose-and sucrose-based media cultivation.