Chromate resistance plasmid in Pseudomonas fluorescens

Abstract

Chromate resistance of Pseudomonas fluorescens LB300, isolated from chromium-contaminated sediment in the upper Hudson River, was found to be plasmid specified. Loss of the plasmid (pLHB1) by spontaneous segregation or mitomycin C curing resulted in a simultaneous loss of chromate resistance. Subsequent transformation of such strains with purified pLHB1 plasmid DNA resulted in a simultaneous reacquisition of the chromate resistance phenotype and the plasmid. When pLHB1 was transferred by conjugation to Escherichia coli, the plasma still conferred chromate resistance.