Characterization of a phenanthrene-degrading microbial consortium enriched from petrochemical contaminated environment

• A novel microbial consortium for complete phenanthrene degradation was developed.
• Several novel putative phenanthrene-degrading bacteria were identified by pyrosequencing.
• Bacterial consortium exhibited an excellent pH adaptation and temperature flexibility.
• Bacterial consortium degraded phenanthrene with few intermediate metabolites accumulation.

In this study, a novel aerobic microbial consortium for the complete degradation of phenanthrene was enriched from petrochemical contaminated soil in Puyang City, Henan Province, China. The consortium, named as ZY-PHE, could degrade more than 96% of 200 mg/L phenanthrene in a minimal salt medium in 3 days. Pyrosequencing analysis of the bacterial 16S rRNA gene suggested that Proteobacteria was the dominant phyla of ZY-PHE consortium representing 56.7% of the total number of detected sequences followed by Actinobacteria (21.7%), Deinococcus-Thermus (14.5%), Bacteroidetes (4.3%) and Firmicutes (0.8%). Several abundant genera, Truepera (14.47%), Starkeya (1.35%), Nitratireductor (1.35%), Legionella (0.71%), Aeromicrobium (0.47%), Phyllobacterium (0.38%) and Cellulosimicrobium (0.31%), have firstly been detected in PAHs contaminated environment. The consortium has the ability to degrade other PAHs such as pyrene and fluorene by utilizing them as sole carbon and energy source. Further, consortium ZY-PHE exhibited an excellent pH adaptation and extensive temperature flexibility, indicating this consortium could function well under a wide range of environmental conditions. Liquid chromatography–quadrupole-time-of-flight mass spectrometry assay revealed accumulation of few intermediate metabolites involved in phenanthrene degradation. The use of this bacterial consortium may be an attractive alternative for the bioremediation of polycyclic aromatic hydrocarbons in the environment.