Isolation and Identification of Preponderant Flora from Kefir Grians

[Objective] To isolate the preponderant flora from kefir grains,and built the groundwork of researching on the symbiosis mechanism of them and exploitation of new taste kefir.[Method] Kefir grains were firstly crushed to pieces and prepared suspensions of these pieces in different concentration,and spread on the malt extract medium,PDA medium,MRS medium or tomato juice medium.They were cultured in the conditions of aerobic and anaerobic at 30 ℃ and 37 ℃ for seven days,and screened the single colonies and observed their shape,and the results of experiments of physiology and biochemistry.[Result] 9 yeasts and 9 lactic acid bacteria were screened from kefir grains,yeast were identified as Kluyveromyces(2),Candida(3),Brettanomyces(4);lactic acid bacteria were identified as Leuconostoc mesenteroides subspecies Dextranicum(1),Lactococcus lactis subspecies Cremoris(2),Lactobacillus kefir(3),Lactobacillus helveticus(1),Lactobacillus delbeueckii subspecies bulgaricus(1),and Lactobacillus delbrueckii subsp.lactis(1).[Result] Total 18 strains were screened from kefir grains,9 of them were yeast,3 of them were lactococcus,and 6 of them were lacbobacillus.