A Whole New Generation of Milk Kefir Grains Formed From Freeze-dried Starter Cultures

Brigitte Richard (1)

1 LCPC/SOA - Département Structures et Ouvrages d'Art

Milk kefir grains (KGs) are composed of a complex symbiotic microbial mixture of bacteria and yeasts growing in kefiran, an extracellular polysaccharide substance of bacterial origin. This is the first report documenting a successful attempt at reforming KGs using pure mixed starter-cultures of microorganisms isolated from KGs, and gain insight into an otherwise hidden world. A milk pouch system designed to concentrate the starter-cultures for 72 h, made this transformation possible. The smaller granules, typically less than 1 mm, have blossomed into a reliable mother-starter and have been reproducing by daily transfers for over three years transforming milk into a delicious beverage. The larger grains, up to about 2 cm (N=12) were considered adequate material for further studies on KGs because each grain had a unique design that could potentially be tracked. They were maintained during repeated cycles for up to four months in a semi-transparent medium enriched with fresh grains which allowed close examination of their morphological features and collective motions in amazing new detail, not otherwise visible in milk. The grains are continually in motion, presumably in search of symbiotic relationships. The data show that clusters of biomass are continually released through cracks and splits, sometimes liberating new ‘baby-grains’ from the ‘mother grains’. Together, they form an intriguing pattern of dynamic grouping suggestive of pair-bonding that have not been visualized, up till now. It can be concluded that a whole new generation of KGs has been created. The original starter cultures became encapsulated in an entirely natural form. It is likely that natural airborne bacteria and yeasts took over at some point to produce symbiotic communities closely interacting together, and able to survive and reproduce. There is still much to discover about the natural behaviors of these amazing creatures.

Mots clés: Kefir grains; symbiosis; milk fermentation; starter-cultures; bacteria; yeasts

Domaines: Sciences du Vivant [q-bio]

Brigitte Richard. A Whole New Generation of Milk Kefir Grains Formed From Freeze-dried Starter Cultures : A Fascinating Insight Into a Hidden World. [Research Report] N/A, Independent researcher. 2016, pp.42. ⟨hal-01251319⟩