Efficient biodegradation characteristics and detoxification pathway oforganophosphorus insecticide profenofos viaCupriavidus nantongensisX1Tand enzyme OpdB br

Profenofos residues in the environment pose a high risk to mammals and non-target organisms. In this study, the bio-degradation and detoxification of profenofos in an efficient degrading strain,Cupriavidus nantongensisX1T,wasinves-tigated. Strain X1Tcould degrade 88.82 % of 20 mg/L profenofos in 48 h. The optimum temperature and inoculationamount of strain X1Tfor the degradation of profenofos were 30-37 degrees C and 20 % (V/V), respectively. Metabolicpathway analysis showed that strain X1Tcould degrade both profenofos and its main metabolite 4-bromo-2-chlorophenol. Metabolite toxicity analysis results showed that dehalogenation was the main detoxification step in pro-fenofos biodegradation. The key gene and enzyme for profenofos degradation in strain X1Twere also explored. RT-qPCR shows that organophosphorus hydrolase (OpdB) was the key enzyme to control the hydrolysis process in strainX1T. The purified enzyme OpdB in vitro had the same degradation characteristics as strain X1T. Divalent metal cationscould significantly enhance the hydrolysis activity of strain X1Tand enzyme OpdB. Meanwhile, strain X1Tcould de-grade 60.89 % of 20 mg/L profenofos in actualfield soil within 72 h. This study provides an efficient biological re-source for the remediation of profenofos residual pollution in the environment.

Automated summary

The efficient degradation and detoxification of profenofos by Cupriavidus nantongensis X1T strain was investigated in this study. The strain could degrade 88.82% of 20 mg/L profenofos in 48 hours and showed high degradation efficiency in actual field soil. This research provides a potential biological resource for the remediation of profenofos residual pollution in the environment.