INTERACTION OF LEAD NITRATE AND CADMIUM CHLORIDE WITH ESCHERICHIA-COLI K-12 AND SALMONELLA-TYPHIMURIUM GLOBAL REGULATORY MUTANTS
INTERACTION OF LEAD NITRATE AND CADMIUM CHLORIDE WITH ESCHERICHIA-COLI K-12 AND SALMONELLA-TYPHIMURIUM GLOBAL REGULATORY MUTANTS
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DOI：
10.1007/bf01569936
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发表时间：
1995-03-01
期刊：
影响因子：
--
通讯作者：
VANDYK, TK
中科院分区：
文献类型：
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作者：
LAROSSA, RA;SMULSKI, DR;VANDYK, TK
为了研究重金属与细胞的相互作用，开发了一种用于肠道细菌生长的基本培养基，该培养基使用甘油-2-磷酸作为唯一的磷源，避免了Pb 2+与无机磷酸盐的沉淀。利用该培养基，分离出了耐Pb（NO3）（2）的大肠杆菌自发突变株。三十五个独立的变异体都赋予了低水平的抗性。用固体平板扩散法测定了E.大肠杆菌和伤寒沙门氏菌、nltriilm突变体在全球监管网络中发生变化，导致Pb（NO3）（2）和CdCl 2。携带axyR和rpoH突变的菌株对这些化合物最敏感。根据菌株的反应完全缺乏所需的同工酶来抑制活性氧，这种超敏铅和镉是由于超氧化物歧化酶，而不是过氧化氢酶水平的改变。类似的伴侣蛋白缺陷突变体的分析表明，这些金属损伤蛋白质在体内。
To investigate the interactions of heavy metals with cells, a minimal medium for the growth of enteric bacteria using glycerol-2-phosphate as the sole phosphorus source was developed that avoided precipitation of Pb2+ with inorganic phosphate. Using this medium, spontaneous mutants of Escherichia coli resistant to addition of Pb(NO3)(2) were isolated. Thirty-five independent mutants all conferred a low level of resistance. Disk diffusion assays on solid medium were used to survey the response of E. coli and Salmonella typh,nltriilm mutants altered in global regulatory networks to Pb(NO3)(2) and CdCl2. Strains bearing mutations in axyR and rpoH were the most hypersensitive to these compounds. Based upon the response of strains completely devoid of isozymes needed to inactivate reactive oxygen species, this hypersensitivity to lead and cadmium is attributable to alteration in super oxide dismutase rather than catalase levels. Similar analysis of chaperone-defective mutants suggests that these metals damage proteins in vivo.