转座子Tn916接合转移诱变棒杆菌

CONJUGATIVE TRANSPONSON TN916 MUTAGENESIS IN CORYNEBACTERIUM

采用滤膜接合法，将大肠杆菌中带有Ｔ＿ｃ抗性的转座子Ｔｎ９１６接合转移到北京棒杆菌ＧＭ９３中其进行诱变。接合频率在１０￣（－７）－１０￣（－８）之间，在没有选择压力的条件下传代培养，接合子是比较稳定的，仍保持Ｔ＿ｃ抗性。Ｔｎ９１６的接合转座作用可以使ＧＭ９３产生营养缺陷型突变，其中氨基酸营养缺陷型占８４％，并得到与Ｌ－Ｉｌｅ产生途径有关的六种氨基酸（Ｔｈｒ，Ｌｙｓ，Ｌｅｕ，Ｍｅｔ，Ｖａｌ，Ｉｌｅ）的缺陷株。

In filter mating between E.coli strain CG120(pAM120)and Corynebacterium BeikinGM93,conjugative transposon Tn916 was used to mutagenize in GM93.The resulting conjugantswere stable and retained the transposon-encoded resistance Te when incubated for several genera-tions under nonselective conditions.The frequency of auxotrophic mutants in the population was88%,in which about 84%requires amino acid.They include the six kinds of amino acid(Thr,Leu,Lys,Met,Val,Ile)which related to the production of L-Ile.