Isolation and characterization of a high molecular mass beta-glucan from Lactobacillus fermentum Lf2 and evaluation of its immunomodulatory activity

摘要

When grown in a semi-defined medium, L. fermentum Lf2 synthesizes significant quantities (similar to 2 g/L) of two exopolysaccharides (EPS). The two EPS were separated by preparative size exclusion chromatography to give a high molecular mass beta-glucan (1.23 x 10(6) Da) and a medium molecular mass heteroglycan (8.8 x 10(4) Da). The structure of the high molecular mass beta-glucan was determined using a combination of NMR spectroscopy, monomer and linkage analysis. The EPS has the following structure: