细菌感受态细胞摄取和分泌DNA的相关性研究① I. 含有质粒的枯草芽孢杆菌自然感受态缺陷突变株的诱变和分离

以携带pUB110质粒的枯草芽孢杆菌BR151菌株为出发菌株，利用亚硝基胍作诱变剂，直接在LB平板上进行诱变。从2949个菌落中筛选出一个转化频率低于出发菌株2～3个数量级的突变株，并对其营养缺陷型、UV的敏感性及Km抗性和质粒进行了检测，确证其转化能力降低为自然感受态缺陷而非营养缺陷型的改变或重组缺陷所致。Abstract　Natural competence-deficient mutant of Bacillus subtilis　BR151, which carries plasmid pUB110, was obtained by nitrosoguanidine mutagenesis on solid medium. From 2949 clones, a mutant, the transformation frequency of which is 102～103　times lower than that of the control, was obtained and tested for the changes of trophic type, resistance to Km, plasmid and sensitivity to UV. The results indicate the reduction of transformation frequency is due to competence-deficient mutation.

Study of the Interrelations Between DNA Uptake and Secreting of Competent Bacterial Cells I. Mutagenesis and Isolation of Natural Competence-deficient Mutant from Containing Plasmid Bacillus subt