Milk Kefir Strains

Strains of bacteria and yeast found in Kefir Grains (and kefir itself):

The following strains are grouped by type, and are the result of years of research from Dominic Anfiteatro, a leading researcher in kefir. We have not personally verified the list.

LACTOBACILLI

Lactobacillus acidophilus
Lb. brevis [Possibly now Lb. kefiri]
Lb. casei subsp. casei
Lb. casei subsp. rhamnosus
Lb. paracasei subsp. paracasei
Lb. fermentum
Lb. cellobiosus
Lb. delbrueckii subsp. bulgaricus
Lb. delbrueckii subsp. lactis
Lb. fructivorans
Lb. helveticus subsp. lactis
Lb. hilgardii
Lb. helveticus
Lb. kefiri
Lb. kefiranofaciens subsp. kefirgranum
Lb. kefiranofaciens subsp. kefiranofaciens
Lb. parakefiri
Lb. plantarum

STREPTOCOCCI/LACTOCOCCI

Streptococcus thermophilus
St. paracitrovorus ^
Lactococcus lactis subsp. lactis
Lc. lactis subsp. lactis biovar. diacetylactis
Lc. lactis subsp. cremoris
Enterococcus durans
Leuconostoc mesenteroides subsp. cremoris
Leuc. mesenteroides subsp. mesenteroides
Leuc. dextranicum ^

YEASTS

Dekkera anomala t/ Brettanomyces anomalus a
Kluyveromyces marxianus t/ Candida kefyr a#
Pichia fermentans t/ C. firmetaria a
Yarrowia lipolytica t/ C. lipolytica a
Debaryomyces hansenii t/ C. famata a#
Deb. [Schwanniomyces] occidentalis
Issatchenkia orientalis t/ C. krusei a
Galactomyces geotrichum t/ Geotrichum candidum a
C. friedrichii
C. rancens
C. tenuis
C. humilis
C. inconspicua
C. maris
Cryptococcus humicolus
Kluyveromyces lactis var. lactis #
Kluyv. bulgaricus
Kluyv. lodderae
Saccharomyces cerevisiae #
Sacc. subsp. torulopsis holmii
Sacc. pastorianus
Sacc. humaticus
Sacc. unisporus
Sacc. exiguus
Sacc. turicensis sp. nov
Torulaspora delbrueckii t
* Zygosaccharomyces rouxii


Legend

t Teleomorph. Sexual reproductive stage. Yeast form pseudo-mycelium as in Flowers of Kefir.
a Anamorph. Asexual reproductive stage. Reproduce by budding or forming spores or cell
splitting [fission].
# Can utilize lactose or lactate.
^ Aroma forming.
subsp. Sub specie type.
sp. Specie type.
sp. nov. New strain or new specie strain type.
biovar. Biological variation strain type.
var. Variety type.

Units Count of Microbes in Gram Stained Kefir Grains
Bacilli [single cells, pair, chains]
Streptococci [pair, chains]
Yeast [single cells]

The Means Range
Bacilli 66, 62-69%
Streptococci 16, 11- 12%
Yeast 18, 16- 20% [11]

Evolution Sequence among Genus Groups during Kefir Culture Cycle
Lactococci > Lactobacilli > Leuconostoc > Yeast > Acetobacter

Microbial Composition of Kefir at End of Fermentation [colony forming units/ml] **
Lactococci : 1,000,000,000
Leuconostocs : 100,000,000
Lactobacilli : 5,000,000
Yeast : 1,000,000
Acetobacter : 100,000

Learn More About Milk Kefir: