菌株簡介
K-12 MG1655是一株K系列的大腸桿菌，經(jīng)檢測無Amp和Kan抗性，可用LB培養(yǎng)基，37℃培養(yǎng)，其代謝類型是異養(yǎng)兼性厭氧型，可用于代謝研究、基因編輯等實(shí)驗(yàn)。 The original K-12 wild-type strain from the Stanford collection contained both the F plasmid and phage lambda. MG1655 was constructed by curing that strain using acridine orange and UV.This strain was sequenced by the Blattner laboratory because it approximates wild-type E. coli and "has been maintained as a laboratory strain with minimal genetic manipulation, having only been cured of the temperate bacteriophage lambda and F plasmid by means of ultraviolet light and acridine orange, respectively." (Blattner, et al. 1997). The mutations listed in the genotype are present in most K-12 strains and were probably acquired early in the history of the laboratory strain. A frameshift at the end of rph results in decreased pyrE expression and a mild pyrimidine starvation, such that the strain grows 10 to 15% more slowly in pyrimidine-free medium than in medium containing uracil (Jensen 1993). The ilvG- mutation is a frameshift that knocks out acetohydroxy acid synthase II (Lawther, et al. 1982). The rfb-50 mutation is an IS5 insertion that results in the absence of O-antigen synthesis (Liu and Reeves 1994). MG1655 was derived and named by Mark Guyer from strain W1485, which was derived in Joshua Lederberg's lab from a stab-culture descendant of the original K-12 isolate. This original E. coli strain K-12 was obtained from a stool sample of a diphtheria patient in Palo Alto, CA in 1922 (Bachmann, B., pp. 2460-2488 in Neidhardt et al.1996, Escherichia coli and Salmonella: Cellular and Molecular Biology, ASM Press).MG1655 grows on LB and M9 minimal medium (+ Glucose + 1ug/ml thiamine).
