Development of a GFP‐based biosensor for detecting the bioavailability and biodegradation of polychlorinated biphenyls (PCBs)

Abstract

Two whole-cell biosensors were constructed to detect the in situ biodegradation of polychlorinated biphenyl by chromosomal insertion of a mini-Tn5-Km r -Pm::gfp(mut3)-T 0 -T 1 construct into P. fluorescens. In vitro tests showed that the expression of the Pm promoter depended on the growth phase of the biosensors and the concentration of chemical in- ducers; chlorinated benzoic acid derivatives. A linear relationship between the fluorescent intensity and the log10 concent- ration of the inducer was observed. One biosensor (F113L::1180gfp) had the ability to degrade PCBs to relevant chloro- benzoic acid derivatives and to induce expression of Gfp. The second biosensor (F113gfp), which cannot degrade PCBs, shows fluorescence after induction by chloro-benzoic acid derivatives. By using these two biosensors, PCB degradation could be detected in vitro and in soil.