Biodegradation of Acid Scarlet 3R by a New Salt-tolerant Strain Alcaligenes faecalis LJ-3: Character, Enzyme and Kinetics Analysis.

Alcaligenes faecalis LJ-3 is highly efficient in degrading various azo dyes (100 mg L-1). Almost 100 % degradation was observed within 16 h at the initial Acid Scarlet 3R concentrations of 1000 mg L-1 under the optimal conditions, which were: 1 g dextrin L-1, 3 g yeast extract L-1, NaCl ≤ 30 g L-1, pH 8.0 and 35-45 ºC. Azoreductase, laccase and NADH-DCIP (nicotinamide adenine dinucleotide-dichlorophenol indophenols) reductase were induced during the degradation of Acid Scarlet 3R. Kinetics study of degradation experiments approximated the first-order reaction. The maximum rate (Vmax) and substrate affinity constant (Ks) were found to be 115.90 mg L-1 h-1 and 1193.23 mg L-1, respectively, using Michaelis-Menten kinetics. This work provides new data characterizing Acid Scarlet 3R degradation by bacteria, as well as practical application potential in biological treatment of industrial effluents containing various azo dyes. [ABSTRACT FROM AUTHOR]