酸乳菌种分离纯化方法

本文研究了在脱脂乳中保藏的发酵酸乳菌种的分离纯化办法。确定了德氏乳杆菌保加利亚亚种的分离纯化培养基为改良MRS，以10^-2稀释度划线分离法在烛缸中厌氧培养可以达到很好的分离效果，添加2％的玉米浆后有利于纯菌株的生长；采用涂布分离法和真空袋培养，在链球菌基础培养基上可很好地分离出唾液链球菌嗜热业种的纯菌株。经鉴定所分离出菌株为纯种后，采用斜面保藏在不含乳基质的培养基上，在15d内可以保持其活力。

The Isolation and Purification of Yoghurt Bacteria

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.