Dynamic microbiota in water kefir: microbial shift and ecological selection during fermentation.

Area of Science:

• Microbiology
• Fermentation Science
• Food Science

Background:

• Water kefir grains (WKG) harbor complex microbial communities.
• Understanding microbial dynamics during water kefir fermentation is crucial for production.

Purpose of the Study:

• To analyze bacterial and fungal microbiota in WKG and fermented water kefir (WK).
• To understand microbial shifts and ecological selection during water kefir fermentation.

Main Methods:

• Comparative analysis of microbial communities in WKG and WK samples.
• Phylogenetic analysis to track microbial succession and adaptation.

Main Results:

• WKG showed high microbial variability, with genera like Clostridium and Acetobacter.
• Fermented WK became homogeneous, dominated by Liquorilactobacillus (bacteria) and Saccharomyces cerevisiae (fungi).
• Low-abundance taxa in grains adapted, while others like Clostridium were eliminated post-fermentation.

Conclusions:

• Water kefir fermentation involves a significant transition from diverse grains to specialized, adapted microbiota.
• Ecological selection shapes the final microbial composition, impacting product quality and consistency.
• Findings offer insights for optimizing artisanal and industrial water kefir production.