Degradation Performance and Optimal Parameters of Two Bacteria in Degrading Nonylphenol

Two bacteria as Pseudomonas Putida and Citrobacter Freundii were selected to degrading nonyphenol (NP). The degradation performance and the optimal parameters were investigated. The results showed that the optimal parameters were culture temperature of 30 Sc, initial culture medium pH of 6 :7, initial NP dosage of 5,ug/mL, initial bacteria dosage of 2% (V/V) and co-metabolic substrate of 2.0 mg/mL peptone. Under the optimal parameters, the highest degradation efficiencies were 49% and 50% for Pseudomonas Putida and Citrobacter Freundii, respectively. The degradation mainly occurred in the first 36 hrs. The mixture of two bacteria presented mutual promotion effect in degrading NP. The optimal ratio of Pseudomonas Putida to Citrobacter Freundii, was 3:2 and the highest NP degradation efficiency achieved about 53%.