Isolation and Characterization of a Novel Phenol Degrading Bacterial Strain WUST-C1

This paper reports the successful isolation and characterization of a novel phenol-degrading bacterial strain WUST-C1 from activated sludge. WUST-C1 is an aerobic, Gram-negative, nonsporulating, and short-rod or peanut-shaped bacterium, which occurs singly, in pairs, but mainly in clusters. 16S rDNA sequence alignment demonstrated this strain belonged to the genus of pseudomonas, with a 99.9% identity to 16S rDNA sequences of Pseudomonas aeruginosa EU170480. It could mineralize up to 1200 mg L-1 phenol within 36 h (99%). Besides phenol, WUST-C1 could grow aerobically on pyrocatechol, alpha-naphthol, hydroquinone, naphthalene, isoquinoline, and indole. WUST-C1 was resistant to ampicillin and chloromycetin. The growth kinetics of strain WUST-C1 on phenol as a sole carbon and energy source at 35 degrees C can be described using Haldane equation. It has a maximum specific growth rate (mu(max)) of 2.47h(-1), a half-saturation constant (K-s) of 48.7 mg L-1, and a substrate inhibition constant (K-i) of 100.6 mg L-1 with a R-2-value of 0.988. Strain WUST-C1 is tolerant to phenol at concentrations up to 1600 mg L-1. Hence, it could potentially be an excellent bacterial candidate for the biotreatment of high-strength phenol-containing industrial wastewaters and for the in situ bioremediation of phenol-contaminated sites.