Survival and Transport of lac-lux Marked Pseudomonas fluorescens Strain in Uncontaminated and Chemically Contaminated Soils

Abstract

Summary Survival of a lac ZY-lux AB strain and rifampicin, ampicillin resistant strain of Pseudomonas fluorescens UG16 in uncontaminated soil and soils containing polycyclic aromatic hydrocarbons (PAHs) and chlorinated phenols was conducted over 7 weeks at 10 and 22°C. Survival of cells containing lac ZY-lux AB reporter gene system determined by viable plating and detection with a charge coupled camera was generally better or similar to the rifampicin, ampicillin resistant strain. Microcosms containing remediated soil with decreased levels of PAHs and chlorinated phenols incubated at 10°C allowed better survival of introduced cells than soil incubated at 22°C, containing higher concentrations of PAHs and chlorinated phenols. Bacterial transport in soil columns of contaminated, bioremediated and uncontaminated control soils was carried out using the lac ZY-lux AB strain of P. fluorescens UG16. Soil columns were flushed with non-sterile rainwater and microorganisms enumerated in the soil profile and leachate. Non-remediated soil containing chemical contaminants displayed lower transport of the inoculated strain. Remediated and uncontaminated soils allowed transport of the introduced bacterial cells through the soil column in into leachate samples.