title: Metal resistance and plasmid DNA in Thiobacillus ferrooxidans.
abstract: The minimal inhibitory concentrations of copper and nickel were determined for each of fifteen isolates of T. ferrooxidans native to a Cu/Ni tailings environment. Ten isolates were inhibited by 160 mM Cu2+ or less, and ten were inhibited by 160 mM Ni2+ or less. The isolates were screened for plasmid DNA using an alkaline lysis method and CCC plasmid forms were confirmed using the Hintermann technique. Two isolates were found to be devoid of plasmid DNA, and only one isolate contained more than two plasmids. Variability existed in plasmid size, although the majority were larger than the standard pBR322 (4.3 kbp). One plasmid was selected for further analysis using restriction endonucleases. EcoRI, HindIII and KpnI all cleaved the plasmid in two locations, and PstI cleaved the plasmid in six locations. PstI-digested fragments of the plasmid were ligated into pBR322, and the recombinant plasmids were transformed into Escherichia coli ATCC 8739. Four genetically-different transformants resulted, and each was grown in media containing 2.0 mM Cu2+ and compared to the growth of a control under similar conditions. There was no conferred copper resistance in E. coli, although one recombinant plasmid appeared to decrease the tolerance for E. coli ATCC 8739 to Cu2+.
authors.affiliation: Department of Biology, Laurentian University Sudbury, Ontario, Canada.
authors.forename: I A
authors.initials: IA
authors.lastname: Chisholm
authors.forename: L G
authors.initials: LG
authors.lastname: Leduc
authors.forename: G D
authors.initials: GD
authors.lastname: Ferroni
mesh_terms: D013856:Acidithiobacillus thiooxidans / Q000187:drug effects* / Q000235:genetics; D003300:Copper / Q000494:pharmacology*; D004262:DNA Restriction Enzymes; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification*; D004352:Drug Resistance, Microbial; D004783:Environmental Microbiology; D007220:Industrial Waste; D008826:Microbial Sensitivity Tests; D008906:Mining; D009532:Nickel / Q000494:pharmacology*; D010957:Plasmids / Q000235:genetics / Q000302:isolation & purification*; D014169:Transformation, Bacterial
chemical_list: D004269:DNA, Bacterial; D007220:Industrial Waste; D003300:Copper; D009532:Nickel; D004262:DNA Restriction Enzymes