Extraction of β-glucan from Saccharomyces cerevisiae: Comparison of different extraction methods and in vivo assessment of immunomodulatory effect in mice

Beta-glucan (BG) is one of the most abundant forms of polysaccharides with the heterogeneous groups of glucose polymers connected by a 1→3 linear β-glycosidic chain hub. BG is unique depending on length and structure of the branches. Even though BG has highly variable branches, 1→4 or 1→6 glycosidic chains are the major branching group (Chan et al., 2009). BG is present everywhere from bacteria to plants with different conformational complexity from single helix to the triple helix, or random coils. BG of yeast cell wall consists of 1→ 3 β-linked glucopyranosyl residues with small numbers of 1→ 6 β-linked branches (Volman et al., 2008). In contrast, the plant (oat and barley) cell walls contains unbranched BG with 1→ 3 and 1→ 4 β-linkage, whereas BG from bacterial origin consist of unbranched 1→ 3 β-linkages (Brown & Gordon, 2003; Brown et al., 2003).