4-Chlorophenol degradation by a bacterial consortium: development of a granular activated carbon biofilm reactor

Abstract

A bacterial consortium that can degrade chloro- and nitrophenols has been isolated from the rhizosphere of Phragmitis communis. Degradation of 4-chlorophenol (4-CP) by a consortium attached to granular activated carbon (GAC) in a biofilm reactor was evaluated during both open and closed modes of operation. During the operation of the biofilm reactor, 4-CP was not detected in the column effluent, being either adsorbed to the GAC or biodegraded by the consortium. When 4-CP at 100 mg l-1 was fed to the column in open mode operation (20 mg g-1 GAC total supply), up to 27% was immediately available for biodegradation, the rest being adsorbed to the GAC. Biodegradation continued after the system was returned to closed mode operation, indicating that GAC bound 4-CP became available to the consortium. Biofilm batch cultures supplied with 10-216 mg 4-CP g-1 GAC suggested that a residual fraction of GAC-bound 4-CP was biologically unavailable. The consortium was able to metabolise 4-CP after perturbations by the addition of chromium (Cr VI) at 1-5 mg l-1 and nitrate at concentrations up to 400 mg l-1. The development of the biofilm structure was analysed by scanning electron microscopy and confocal laser scanning microscopy (CLSM) techniques. CLSM revealed a heterogeneous structure with a network of channels throughout the biofilm, partially occupied by microbial exopolymer structures.

Degradation of Phenol by Mixed Culture of Locally Isolated Pseudomonas Species

“…Degradation of mono-chlorophenol and phenol by mixed microbial community were reported [7,14,15]. Although four isolates capable of degrading phenol of various concentrations, most of the cases, the degradation rate of a mixed culture was determined as being significantly higher that for any of the individual strains.…”

Isolation and characterization of a Rhodococcus strain able to degrade 2-fluorophenol

“…This soil (approximately 5 g) was used to inoculate 250-ml flasks containing 50 ml of sterile mineral salts medium (MM) (Caldeira et al 1999) and 2-FP supplied as the sole carbon and energy source at a concentration of 0.44 mM. Cultures were incubated in an orbital shaker (100 rpm) at 25°C.…”

Modeling 1,2-dichloroethane biodegradation by Klebsiella oxytoca va 8391 immobilized on granulated activated carbon

“…Therefore, we were interested in finding a way to decrease the adverse effects of substrate inhibition or toxicity. Immobilization of microbial cells on granulated activated carbon is one of the best approaches for solving this problem [6][7][8][9][10][11][12][13][14][15][16][17][18][19].…”