GALACTOMYCES GEOTRICHUM ISOLATED FROM WATER KEFIR: INTERACTION WITH LACTOBACILLUS KEFIR

In this study, a yeast-like fungus strain wk1 isolated from water kefir grains was identified as Galactomyces geotrichum, which had great adhesion ability with Lactobacillus kefir. Exposure to lithium chloride aroused the marked loss of attached bacteria, while acetic acid treatment led to a thicker adhesion. Heat and sodium hydroxide treatment had nonsignificant effect on the interaction. Furthermore, G. geotrichum wk1 showed its hydrophobic and basic phenotype with strong electron donor property, contributing to the extremely strong auto-aggregation ability. These properties were greatly weakened after all pretreatments, except LiCl treatment, coincided with the low auto/co-aggregation ability. The results in this study may be helpful to understand the interactions of participating bacteria and fungi in the kefir grains and its role for the grain formation.