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Hydrocarbon degradation by thermophilic Nocardia otitidiscaviarum strain TSH1: physiological aspects
Author(s) -
Zeinali Majid,
Vossoughi Manouchehr,
Ardestani Sussan K.,
Babanezhad Esmaeil,
Masoumian Mohamadreza
Publication year - 2007
Publication title -
journal of basic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0233-111X
DOI - 10.1002/jobm.200700283
Subject(s) - thermophile , bioremediation , hydrocarbon , chemistry , hexadecane , nocardia , toluene , strain (injury) , phenol , biodegradation , xylene , aromatic hydrocarbon , polycyclic aromatic hydrocarbon , environmental chemistry , organic chemistry , bacteria , biology , anatomy , genetics , enzyme
Indigenous thermophilic hydrocarbon degraders are of special significance for the bioremediation of oil‐contaminated desert soils with ambient temperature of 45–50 °C. The first objective of this study was to demonstrate the hydrocarbon‐degrading capability of Nocardia otitidiscaviarum TSH1 (DSM 45036) which grows optimally at 50 °C. Analysis of the metabolic profile of the strain TSH1 showed that it could metabolize phenol, intermediate‐chain‐length n ‐alkanes and some polycyclic aromatic hydrocarbons (PAHs) ranging in size from two to four fused rings efficiently, but not toluene and xylene. N. otitidiscaviarum TSH1 was able to survive and grow at phenol concentrations up to 875 mg l –1 . For the first time, the physiological response of a thermophilic Nocardia strain to poorly available hydrophobic compounds was also investigated. When grown on a mineral salt medium with hexadecane, N. otitidiscaviarum TSH1 showed very high affinity for the organic phase. Additionally, PAH‐grown cells were considerably hydrophobic. The capacity of PAH‐utilizing N. otitidiscaviarum TSH1 isolate to produce biosurfactants was also investigated. Fatty acids (C 14 –C 18 ) were detected by GC‐MS analysis during bacterial growth in PAH supplemented mineral media. High cell surface hydrophobicity and capability of N. otitidiscaviarum TSH1 to degrade different hydrocarbons at 50 °C may make it an ideal candidate to treat oil‐contaminated desert soils. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)