Applied Microbiology and Biotechnology

, Volume 95, Issue 3, pp 789–798

Biodegradation of polycyclic aromatic hydrocarbons by a halophilic microbial consortium

Authors

  • Seyed Mohammad Mehdi Dastgheib
    • Department of Biotechnology, College of ScienceUniversity of Tehran
    • Extremophile Laboratory, Department of Microbiology, School of Biology, College of ScienceUniversity of Tehran
  • Khosro Khajeh
    • Department of Biochemistry, Faculty of Biological ScienceTarbiat Modares University
  • Mahmoud Shavandi
    • Biotechnology Research CenterResearch Institute of Petroleum Industries
  • Antonio Ventosa
    • Department of Microbiology and Parasitology, Faculty of PharmacyUniversity of Sevilla
Environmental biotechnology

DOI: 10.1007/s00253-011-3706-4

Cite this article as:
Dastgheib, S.M.M., Amoozegar, M.A., Khajeh, K. et al. Appl Microbiol Biotechnol (2012) 95: 789. doi:10.1007/s00253-011-3706-4

Abstract

In this study we investigated the phenanthrene degradation by a halophilic consortium obtained from a saline soil sample. This consortium, named Qphe, could efficiently utilize phenanthrene in a wide range of NaCl concentrations, from 1% to 17% (w/v). Since none of the purified isolates could degrade phenanthrene, serial dilutions were performed and resulted in a simple polycyclic aromatic hydrocarbon (PAH)-degrading culture named Qphe-SubIV which was shown to contain one culturable Halomonas strain and one unculturable strain belonging to the genus Marinobacter. Qphe-SubIV was shown to grow on phenanthrene at salinities as high as 15% NaCl (w/v) and similarly to Qphe, at the optimal NaCl concentration of 5% (w/v), could degrade more than 90% of the amended phenanthrene in 6 days. The comparison of the substrate range of the two consortiums showed that the simplified culture had lost the ability to degrade chrysene but still could grow on other polyaromatic substrates utilized by Qphe. Metabolite analysis by HPLC and GC–MS showed that 2-hydroxy 1-naphthoic acid and 2-naphthol were among the major metabolites accumulated in the Qphe-SubIV culture media, indicating that an initial dioxygenation step might proceed at C1 and C2 positions. By investigating the growth ability on various substrates along with the detection of catechol dioxygenase gene, it was postulated that the uncultured Marinobacter strain had the central role in phenanthrene degradation and the Halomonas strain played an auxiliary role in the culture by utilizing phenanthrene metabolites whose accumulation in the media could be toxic.

Keywords

Polycyclic aromatic hydrocarbons (PAHs)PhenanthreneBiodegradationHalophileMarinobacterHalomonasConsortium

Copyright information

© Springer-Verlag 2011