Biodegradation of oxadiazon by a soil isolated Pseudomonas fluorescens strain CG5: Implementation in an herbicide removal reactor and modelling

摘要

An oxadiazon-degrading bacterial, Pseudomonas strain CG5, was isolated from an agricultural contaminated soil. This strain CG5 was able to grow on 10 mg of oxadiazon per 1, yielding 5.18 ± 0.2 mg of protein biomass mol~(-1). GC-MS analyses of the metabolites from oxadiazon catabolism revealed its dehalogenation and degradation to form non-toxic end-products, cells were then immobilized by adsorption on a ceramic support to be used as biocatalysts in herbicide removal biofilm-reactor processes. Seventy-two per cent of the oxadiazon was removed, and the maximum specific substrate uptake rate was 10.63 ± 0.5 μg h~(-1)mg~(-1) prot. A new mathematical model was developed to interpret and predict the behaviour of the bacteria and pollutants in a biofilm-reactor system, to consider biofilm structural and morphological properties.