Abstract:Organophosphorus insecticides (OPs) have been widely used to control agricultural pests, which has raised concerns about OPs residues in crops and the environment. The research group had previously isolated a highly efficient OPs degradation strain , Cupriavidus nantongensis X1T. In this study, the degradation characteristics of chiral organophosphorus pesticide profenofos by strain X1T under different substrate concentrations, bacterial counts, pH and metal ions were measured. The results showed that strain X1T could preferentially degrade S-profenofos with high toxicity and low insecticidal activity. With the increase of substrate concentration, the degradation rate of profenofos by strain X1T gradually slowed down the optimal pH of profenofos degradation by strain X1T was 7.5; the valence state of metal ions was an important factor to affect the degradation of profenofos, of which Cr3+ and Fe3+ could inhibit the degradation of profenofos, while Ca2+, Mn2+, Mg2+, Co2+, Ni2+ could promote the degradation of S-profenofos. Meanwhile, there was no significant difference between the degradation rate of S-profenofos and R-profenofos by the crude enzyme in strain X1T and purified enzyme opdB. The results provide a theoretical basis for bioremediation of profenofos residuals.