摘要
从工程应用的角度研究了重组Ｅ．ｃｏｌｉＨＭＳ１７４（ｐＴＺ１８Ｕ－ＰＨＢ）的质粒稳定性，结果表明，质粒ｐＴＺ１８Ｕ－ＰＨＢ具有结构稳定性和分裂不稳定性，ＰＨＢ在胞内的大量积累和重组菌较低的生长速率增加了质粒的分裂不稳定性。为了保证细胞的正常生长及表达，在种子培养基中必须添加氨苄青霉素（Ａｐ）；由于接种时种子带入的１０ｍｇ／ＬＡｐ足以杀死丢失了质粒的细胞，因而在摇瓶发酵阶段不必再添加Ａｐ。在ＬＢ和ＬＢＧ培养基中传代１８次后，带质粒的菌分别为７．４％和３．５％；细胞每分裂一次，质粒的平均丢失率分别为０．９６％和０．９３％。
In the view point of engineering application, the plasmid stability of recombinant E.coli HMS174 (pTZ18U PHB) was investigated. It showed that the plasmid pTZ18U PHB had structural stability and segregational instability. Plasmid segregational instability was aggravated by the much accumulation of intracellularPHB and the lower growth rate of the recombinant strain. The supplement of Ap was necessary for seed culture so as to ensure cell growth and expression normally, and had no need for flask culture because 10 mg/L Ap brought from inoculum was enough to kill plasmid free cells. In LB and LBG, the fractions of plasmid harboring cell decreased to 7.4% and 3.5% , respectively, over 18 generations. The probabilities of plasmid lost during each divided in LB and LBG were 0.96%and 0.93%, respectively. The sensitivity kinetic equation of wild type strain and the plasmid lost kinetic equation of recombinant strain were also set up.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
1997年第6期46-49,共4页
Journal of Tsinghua University(Science and Technology)
关键词
大肠杆菌
PHB
质粒稳定性
发酵
poly β hydroxybutyrate(PHB)
recombinant E.coli
plasmid stability
