关键词: 德氏乳杆菌保加利亚亚种, 唾液链球菌嗜热亚种, 酸乳, 分离纯化

Abstract: This paper studied mainly on the isolation and purification method of yoghurt bacteria, which keep in degrease milk.The isolation and purification medium for L. delbrueckii subsp. bulgaricus were defined as improving MRS, after streaking platewith 10-2 dilution degree, place in desiccator burning candle to consume its oxygen, the result showed that this method can attainits well separation. Increasing 2% corn syrup in its liquid medium, the growth of the pure strain showed the notability effect. Aftersmearing culture using vacuum seals plastic bag, in the streptococcus basic medium could nicely separate the streptococcussalivarius subsp. thermophilus pure strain. Identifing the isolated strain of yoghurt and make sure it was pure strain, adoptinginoculation of an agar slant conserve in medium which not containing milk source, could keep them vitality in 15 days.

Key words: Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus salivarius subsp. thermophilus, yoghurt, isolation and purification