Structural differences on cell wall polysaccharides of brewer's spent Saccharomyces and microarray binding profiles with immune receptors

Brewing practice uses the same yeast to inoculate the following fermentation (repitching). Saccharomyces pas-torianus, used to produce Lager beer, is widely reused, not changing its fermentation performance. However, S. cerevisiae, used to produce Ale beer, is partial or not even reused, due to its poor performance. It is hypoth-esized that cells modulate their wall polysaccharides to increase the cell-wall strength. In this work industrial S. cerevisiae and S. pastorianus brewer's spent yeasts with different repitching numbers were studied. Glucans were the main component of S. cerevisiae whereas mannoproteins were abundant in S. pastorianus. The major changes were noticed on glucans of both species, & beta;1,3-glucans decrease more pronounced in S. cerevisiae. The increase of & alpha;1,4-Glc, related with osmotolerance, was higher in S. cerevisiae while & beta;1,4-Glc, related with cell-wall strength, had a small increase. In addition, these structural details showed different binding profiles to immune receptors, important to develop tailored bioactive applications.

Automated summary

Brewing practice involves reusing the same yeast for subsequent fermentations. The yeast used for Lager beer (Saccharomyces pastorianus) is widely reused without changes in fermentation performance. However, the yeast used for Ale beer (Saccharomyces cerevisiae) is either partially or not reused due to poor performance. The study found that cells modulate their wall polysaccharides to increase cell wall strength.