The biofilm hypothesis: The formation mechanism of Tibetan kefir grains

摘要

The anatomical structure of Tibetan kefir grains (TKGs), and the monosaccharides and characteristics of the exopolysaccharides (EPS) under different conditions were explored. Tibetan kefir grains are internal vesicle-like grains containing liquid polysaccharides, and these proliferate in an umbilical cord'-like manner. Lactic acid bacteria are located on the outside and acetic acid bacteria on the inner surface of the TKGs. Biofilms of Acetobacter orientalis and the TKGs showed that they had similar monosaccharide compositions. The apparent viscosity of the EPS positively correlated with the polysaccharide concentration and negatively correlated with the shear rate. A biofilm hypothesis of the TKG formation mechanism was proposed.