Popis: |
The degradation of diphenylamine (DPA) by pure Pseudomonas (P. cepacia, P. putida, P. resinovorans) and mixed activated sludge cultures in batch shaker flasks and bioreactor systems is described. The experiments were carried out at initial DPA concentrations in the range of 15–60 mg/l. Under the experimental conditions, all cultures were capable of degrading DPA, as a sole carbon source, at comparable rates. Addition of glucose as a co‐substrate was found not to have an effect on the apparent biodegration rates. In the range of initial substrate concentrations attempted in this study, the DPA biodegradation rate was found to follow first‐order kinetics. In bioreactor experiments, the biodegradation rate constant (kl) was determined to be 0.54 d‐1 corresponding to a half‐life (t½) 1.40 days. The effect of these findings on the storage stability of nitrocellulose based propellant formulations are discussed. |