At beginning, we find that PNP can be degraded to 4-nitrocatechol at the presence of enzyme NphA1 and NphA2. So we transform a plasmid containing these two genes into E.coli. Then we add PNP into the bacteria solutions when the recombinational bacteria are incubated to OD 0.3 to form a gradient concentration. After adding PNP, we use microplate reader to measure pnp's characteristic absorption peak changes every 2 hours in 3 repeated experiments. We spend 36 hours to track the change of the absorption. Though we measure the changes day and night, unfortunately, experiment results turned out not so perfectly. We cannot find obvious degradation of the PNP.

     We find another pathway to degrade PNP in 5 steps with 4 enzymes in Rhodococcus sp. Strain PN1, but the problem is that we fail to locate one of the essential enzyme gene. So we only transformed 2 plasmids with 3 genes into E.coli and measure the changes using the same method above. Sadly, PNP concentration only reduces little to some extent.