title: Continuous degradation of mixtures of 4-nitrobenzoate and 4-aminobenzoate by immobilized cells of Burkholderia cepacia strain PB4.
abstract: Although isolated on 4-aminobenzoate, Burkholderia cepacia strain PB4 is also able to grow on 4-nitrobenzoate. Degradation of an equimolar mixture of the nitroaromatic compound 4-nitrobenzoate and its corresponding aminoaromatic derivative 4-aminobenzoate by this strain was investigated. Batch experiments showed that, irrespective of preculturing conditions, both compounds were degraded simultaneously. The mixture-degrading ability of B. cepacia strain PB4 was subsequently tested in continuous packed bed reactors (PBR) with the strain immobilized on Celite grade R-633 or R-635. Higher degradation rates were achieved with the larger particles of Celite R-635. Maximum simultaneous degradation rates per liter of packed bed of 0.925 mmol 1(-1) h(-1) 4-nitrobenzoate and 4-aminobenzoate were obtained for an applied loading rate of the same value (0.925 mmol 1(-1) h(-1) of each compound). Even when the applied load was not removed in its entirety, neither of the two compounds was degraded preferentially but a percentage of both of them was mineralized. The present study shows the possibility for a pure strain to biodegrade not only a nitroaromatic compound (4-nitrobenzoate) but also its corresponding amino derivative (4-aminobenzoate) continuously and simultaneously.
authors.affiliation: Unit of Bioengineering, Catholic University of Louvain, Belgium.
authors.forename: C M
authors.initials: CM
authors.lastname: Peres
authors.forename: B
authors.initials: B
authors.lastname: Van Aken
authors.forename: H
authors.initials: H
authors.lastname: Naveau
authors.forename: S N
authors.initials: SN
authors.lastname: Agathos
mesh_terms: D010129:4-Aminobenzoic Acid / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors; D016956:Burkholderia cepacia / Q000378:metabolism*; D018914:Cells, Immobilized; D005240:Feasibility Studies; D007220:Industrial Waste; D009579:Nitrobenzoates / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D007220:Industrial Waste; D009579:Nitrobenzoates; D014874:Water Pollutants, Chemical; C008629:4-nitrobenzoic acid; D010129:4-Aminobenzoic Acid