Taxonomic and functional analysis of a water kefir fermentation ecosystem through shotgun metagenomic sequencing

Water kefir is a beverage made by the fermentation of an aqueous sucrose solution in the presence of dried figs and water kefir grains. The water kefir grains are polysaccharide grains harboring bacteria and yeasts, which ferment sucrose to produce exopolysaccharides (necessary for water kefir grain growth) and metabolic end-products. In the present study, the taxonomic composition and functional potential of water kefir microbiota in both water kefir grains and water kefir liquor at two time points (24 h and 72 h) in a water kefir fermentation were studied through shotgun metagenomic sequencing.