CdCl2对质粒的生态效应及质粒在其宿主抗镉性中的作用

用ＣｄＣｌ２处理体外或大肠杆蓖体内质粒ｐＷＨ５８后，通过琼脂糖电泳和限制性内切酶分析，研究了Ｃｄ对质粒ＤＮＡ结构的影响。通过比较带质粒与不带质粒大肠杆菌在含不同浓度ＣｄＣｌ２的氨苄ＬＢ与无抗ＬＢ培养液中的生长量，研究了Ｃｄ对大肠杆菌体内质粒的影响及质粒在其宿主Ｃｄ耐性的作用。结果表明，体外、体内ＣｄＣｌ２处理对质粒ｐＷＨ５８ ＤＮＡ结构无明显诱变性。Ｃｄ胁迫下大肠杆菌体内质粒ｐＷＨ５８可进行复制传

Ecological effect of CdCl2 on plasmid and role of plasmid in Cd-tolerance of its host

After treating the plasmid of Escherichia coli HB101 by CdCl2 in vitro or in vivo, the effect of Cd on the structure of plasmid pWH58 DNA was studied through argarose gel electrophesis and restriction fragment length polymorphism analysis. By comparing the growth of E. coli with and without plasmid cultured in the medium with Amp LB and non-anti LB under different concentrations of CdCl2, the effect of Cd on plasmid E. coli of in vivo and the role of plasmid in Cd-tolerance of its host were studied. Cd treatments of E. coli in vitro or in vivo didn't cause an obvious change of the structure of plasmid pWH58 DNA. Plasmid pWh58 could replicate for regeneration and gene express under Cd stress. Plasmid pWH58 of E. coli in vivo lowered Cd-tolerance of its host form 75 mg.L-1 to 50 mg.L-1. Cd-tolerance of E. coli ascended markedly after Cd taming, but had a trend of reversing to original level after restoration, indicating that Cd-tolerance of E. coli could be tamed, but the tamed Cd-tolerance still had no genetic basis.