The microbial flora of sugary kefir grain (the gingerbeer plant): biosynthesis of the grain fromLactobacillus hilgardii producing a polysaccharide gel

Microbial Species Diversity, Community Dynamics, and Metabolite Kinetics of Water Kefir Fermentation

“…ater kefir is a fermented beverage that is made by adding water kefir grains, which are polysaccharide grains that serve as the inoculum, to a mixture of water, sugar (sucrose), dried figs, and possibly other ingredients such as lemon, depending on the recipe (1)(2)(3)(4)(5). After 2 to 4 days of anaerobic incubation at room temperature, a sparkling, yellowish fermented beverage is obtained that has a fruity, acidic, slightly sweet, and slightly alcoholic taste and aroma.…”

“…It has been postulated that the polysaccharide grains originate from the leaves of the Opuntia cactus fig plant (6). Besides the use of the name "water kefir grains" in western Europe, other names are also in use for this fermented beverage inoculum, depending on the geographic location, such as "ginger beer plants," "Tibicos," "Tibi grains," "California bees," "African bees," "ale nuts," "balm of Gilead," "Bèbées," "Japanese beer seeds," and "sugary kefir grains" (2,(5)(6)(7)(8)(9).…”

“…Currently, research on water kefir is still very limited and most of the scientific information available deals with its species diversity (2,4,5,(8)(9)(10)(11)(12)(13)(14)(15)(16). Also, the chemical and structural composition of the water kefir grain polysaccharide has been studied (6, 7, 10-12, 15, 17-19).…”

“…Hence, a systematic approach for the study of the microbiology of water kefir fermentation is necessary. Further, it is known that the water kefir grain polysaccharide consists of dextran, an ␣-(1¡6)-linked glucose polymer, produced by certain Lactobacillus and/or Leuconostoc species (5,7,11,(17)(18)(19). However, until now no thorough metabolite analysis has been performed on a water kefir fermentation process.…”

Kefir D’Aqua and Its Probiotic Properties

“…Accordingly, it has been stated [18] that separated cultures of microbial kefir grains, either do not grow in milk or have a decreased biochemical activity, which further complicates the study of the microbial population of kefir grains. The mechanism of symbiogenesis of kefir grains from distinct strains of unicellular organisms is unknown, although there are some data about the recover of their structure and probiotic properties from lyophilization, and even so, about the formation of an artificial consortium produced by bits of kefir grains transferred to a yeast extract-sucrose solution [19]. Using a simple approach, we had developed artificial cultures of kefir by trapping their strains in alginate beads [20].…”