Biodegradation of phenanthrene by Rhizobium petrolearium SL-1.
OBJECTIVE
We aimed to investigate the phenanthrene degradation characteristics and possible phenanthrene degradation pathways of Rhizobium petrolearium SL-1.


RESULTS
Using high-performance liquid chromatography (HPLC), UV-visible and gas chromatography-mass spectrometry (GC-MS) analysis, the phenanthrene-degrading properties and metabolites of Rh. petrolearium SL-1 were analysed, and then combined with genome-based analysis to elucidate the possible biodegradation pathway of phenanthrene in Rh. petrolearium SL-1. The results of the analyses showed that phenanthrene (100 mg l-1) was completely degraded by strain SL-1 at 35°C, 0·02% salinity and pH 9·0 within 3 days. A wide range of polycyclic aromatic hydrocarbons, including naphthalene, fluorene, anthracene and pyrene, could also be degraded by this strain.


CONCLUSIONS
Based on the identified metabolites, the utilization of probable intermediates and the presence of putative phenanthrene catabolic genes, we concluded that phenanthrene was degraded via two different routes, namely the 'naphthalene' and the 'phthalic acid' routes.


CONCLUSIONS
For the first time, this study shows the degradation pathway of phenanthrene by a Rhizobium strain. Because of its excellent stress resistance, metabolic versatility, high degradation efficiency and potential application in phytoremediation, Rh. petrolearium SL-1 is a potential candidate for the bioremediation of polycyclic aromatic hydrocarbons-contaminated areas.
Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China.|College of Resources Environment and Tourism, Capital Normal University, Beijing, China.
X
X
Huang
State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, China.
J
J
Shi
State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, China.
C
C
Cui
School of Minerals Processing and Bioengineering, Central South University, Changsha, China.
H
H
Yin
Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China.|College of Resources Environment and Tourism, Capital Normal University, Beijing, China.
R
R
Zhang
Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China.
X
X
Ma
Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China.
X
X
Zhang
D001673:Biodegradation, Environmental; D004785:Environmental Pollutants / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D009281:Naphthalenes / Q000378:metabolism; D010616:Phenanthrenes / Q000378:metabolism*; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism; D012231:Rhizobium / Q000235:genetics / Q000378:metabolism*
D004785:Environmental Pollutants; D009281:Naphthalenes; D010616:Phenanthrenes; D011084:Polycyclic Aromatic Hydrocarbons; C031181:phenanthrene

Rhizobium
; biodegradation; degrading properties; metabolic pathway; phenanthrene