Naphthalene Degradation Capability and Molecular Phylogeny of a Bacterial Strain NAP A Isolated from Wastewater

In the study, a selective medium was used to enrich and isolate a naphthalene-degrading bacterium NAP_A from the activated sludge of Zhangdian Municipal Wastewater Treatment Plant in Zibo, China. Cultivation and gas chromatography analysis showed NAP_A degraded naphthalene fast under 30degC~35degC and pH7. The 16S rRNA gene of NAP A was cloned and sequenced (EU142847). Basing on this sequence and its related sequences in the GenBank database, a multialignment was conducted then a phylogenetic tree was constructed with DNAMAN software. The results showed that strain NAP_A was located in the lineage of Ochrobactrum genus, sharing the highest homology with O. pseudintermedium (99%), which indicated the strain was a member of O. pseudintermedium. This revealed for the first time that Ochrobactrum species could degrade polycyclic aromatic hydrocarbon, which would guide the biotreatment of such environmental contaminant with the bacterium.