A novel source for the commercial synthesis of Yeast β-glucans

A novel source for the commercial synthesis of yeast β-glucans was investigated by Varelas et al. (2016). The group isolated β-glucans for the first time from winery spent yeast biomass. During the winemaking process, a byproduct known as wine lees is produced. Most byproducts include spent yeasts, bacteria, tartaric acid, ethanol, phenolics, and pigments. Thus, β-glucans can be sourced from the yeast waste biomass that accumulates in wine tanks throughout the winemaking process. This study showed that the isolated β-glucans contained some amount of tartaric acid and polyphenols, which could not be omitted. Considering wine lees, especially red ones, are more complex mixes than brewery wastes, the purity of β-glucans in wine lees samples was lower than the purity reported by other studies from brewery wastes. Nonetheless, this work identifies a valuable waste source of β-glucans that are most often disposed of in landfills.

The structure and content of molasses yeast β-glucans were investigated using High-Performance Liquid Chromatography (HPLC) and NMR. In addition, the effects of β-glucans on the Abelson leukaemia virus-transformed monocyte/macrophage cell line (RAW 264.7) challenged with LPS were investigated. The product yield was reduced due to the yeast cell state. Compared to freshly produced yeast in the laboratory, the yeast waste material was damaged and partially deactivated before extraction. The β-glucan sample demonstrated very effective immune-modulating properties. The extract significantly suppressed TNF-α compared to the positive control and considerably reduced IL-6 production.