嗜酸乳杆菌DOMLa菌株thyA基因突变株的筛选

The screen for thyA gene mutant strain of Lactobacillus acidophilus DOM La

为构建以ｔｈｙＡ基因为选择标记的嗜酸乳杆菌染色体－质粒致死平衡系统。我们建立了嗜酸乳杆菌ｔｈｙＡ基因突变菌株的筛选方法。从含有三甲氧卞氨嘧啶（ＴＭＰ）２０μｇ／ｍｌ和胸腺嘧啶（ｔｈｙｍｉｄｉｎｅ）５０μｇ／ｍｌ的改良ＭＲＳ培养基中筛选了１００株突变株，从中确定一株生物学性状稳定的菌株ＤＯＭＬａＦ８４作为进一步研究的受体侯选菌株。

In order to construct the chromosome plasmid balanced lethal system for Lactobacillus acidophilus strain DOM La with the thyA gene as a house keeper. The screen method for thyA mutant strain of Lactobacillus acidophilus was developed. We screened the thyA gene mutate Lactobacillus acidophilus strain by using modified MRS medium. 100 strains of thyA mutate L.Acidophilus was screened by using modified MRS medium containing trimethoprim (TMP) 20μg/ml and thymidine 50μg/ml. The most stable strain of the mutate L.Acidophilus DOM LaF84 was defined as delivery vector candidate for further study.