Kefir and e-coli

[Guest guest]

I found this interesting bit on Medline ... I'd guess it's pretty difficult for

e-coli to grow in your kefir culture even if it did get contaminated!

Milk and MRS broth fermented with kefir grains from different households were

examined for inhibitory activity toward gram-negative and gram-positive strains.

Fermented milk obtained with 10 g per 100 ml of inoculum (final pH 3.32 to 4.25)

and MRS broth fermented with 1 and 10 g per 100 ml of inocula (final pH 4.18 to

5.25) had inhibitory power demonstrated by spot test and agar well diffusion

assay. This inhibitory effect could be assigned to the undissociated form of

lactic and acetic acid produced during the fermentation process. Kefir

supernatants inhibited the growth of Escherichia coli 3 in nutrient broth at 37

degrees C for 24 h. However, supernatants of yogurt or milk artificially

acidified with lactic and acetic acids allowed the growth of E. coli 3 in the

same conditions. A bacteriostatic effect of milk fermented with kefir grains

over E. coli 3 was also demonstrated.

Heidi Schuppenhauer

Trillium Custom Software Inc.

heidis@...