Kinetics and mechanisms of p-nitrophenol biodegradation by Pseudomonas aeruginosa HS-D38

摘要

The kinetics and mechanisms of p-nitrophenol(PNP)biodegradation by Pseudomonas aeruginosa HS-D38 were investigated. PNP could be used by HS-D38 strain as the sole carbon,nitrogen and energy sources,and PNP was mineralized at the maximum concentration of 500 mg/L within 24 h in an mineral salt medium(MSM).The analytical results indicated that the biodegradation of PNP fit the first order kinetics model.The rate constant kPNP is 2.039×10-2/h in MSM medium,KPNP+N is 3.603×10-2/h with the addition of ammonium chloride and KPNP+C is 9.74×10-3/h with additional glucose.The addition of ammonium chloride increased the degradation of PNP.On the contrary,the addition of glucose inhibited and delayed the biodegradation of PNP.Chemical analysis results by thin-layer chromatography(TLC),UV-Vis spectroscopy and gas chromatography(GC)techniques suggested that PNP was converted to hydroquinone(HQ)and further degraded via 1,2,4-benzenetriol(1,2,4-BT)pathway.