Pseudomonas fluorescens survival and plasmid RP4 transfer in agricultural water

Abstract

Transfer of plasmid RP4 via conjugation between introduced Pseudomonas fluorescens donor and recipient cells was studied in agricultural surface water samples at 22°C over a 10 day period. Transconjugants were recovered when the water was sampled after 3 and 10 days incubation, from non-sterile (unfiltered) surface water that was amended with dilute tryptone-yeast extract (TY) broth and 0.1% (v/v) bentonite clay slurry. RP4 plasmid transfer was not observed in unamended filtered water samples inoculated with donor and recipient cells. However, viable donor and recipient cells were usually present in reduced numbers in most water samples after 10 days.