[Isolation of phenol-degrading bacteria from coking wastewater and their degradation gene]

Phenol and phenolic compounds are main pollutants in wastewater of coking factories. To identify the bacteria responsible for phenol removal in the activated sludge of a coking factory, we isolated bacteria from the sludge directly or after enrichment. From two samples from the aerobic and anaerobic pools, 28 strains belonging to 28 species of 20 genera were obtained after identification with BOX-PCR and further 16S rDNA sequence analyses. Most of them belonged to beta- and gamma-Proteobacteria, four of which are potential novel species of low 16S rDNA sequence similarity to corresponding type strains. From the m-cresol enrichment community, two strains identified and named as Pseudomonas monteilii GCS-AE-J-1 and Pseudomonas plecoglossicida GCS-AN-J-3 were obtained as the efficient degraders; The former can remove 94.6% m-cresol (791 mg/L) in just 48 h; while the latter metabolized 92.2% m-cresol (763 mg/L). Furthermore, the phenol hydroxylase gene was surveyed by PCR from the phenol-degrading strains,and 4 were positively detected. Summarily, quite diverse bacteria were proved of high capability to degrade phenol and phenolic compounds in this report, which play important role in biotreatment of phenol compounds.