Zeinali Majid, Vossoughi Manouchehr, Ardestani Sussan K, Babanezhad Esmaeil, Masoumian Mohamadreza
Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran.
J Basic Microbiol. 2007 Dec;47(6):534-9. doi: 10.1002/jobm.200700283.
Indigenous thermophilic hydrocarbon degraders are of special significance for the bioremediation of oil-contaminated desert soils with ambient temperature of 45-50 degrees C. The first objective of this study was to demonstrate the hydrocarbon-degrading capability of Nocardia otitidiscaviarum TSH1 (DSM 45,036) which grows optimally at 50 degrees 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 degrees C may make it an ideal candidate to treat oil-contaminated desert soils.
本土嗜热烃降解菌对于生物修复温度在45 - 50摄氏度的受石油污染的沙漠土壤具有特殊意义。本研究的首要目标是证明耳炎诺卡氏菌TSH1（DSM 45,036）的烃降解能力，该菌株在50摄氏度时生长最佳。对菌株TSH1的代谢谱分析表明，它能够有效代谢苯酚、中链长度的正构烷烃以及一些大小在两个到四个稠合环之间的多环芳烃（PAHs），但不能代谢甲苯和二甲苯。耳炎诺卡氏菌TSH1能够在苯酚浓度高达875 mg l(-1)的环境中存活和生长。首次还研究了嗜热诺卡氏菌菌株对难利用的疏水性化合物的生理反应。当在含有十六烷的矿物盐培养基上生长时，耳炎诺卡氏菌TSH1对有机相表现出非常高的亲和力。此外，在PAH上生长的细胞具有相当强的疏水性。还研究了利用PAH的耳炎诺卡氏菌TSH1分离株产生生物表面活性剂的能力。在添加了PAH的矿物培养基中细菌生长期间，通过GC-MS分析检测到了脂肪酸（C(14)-C(18)）。耳炎诺卡氏菌TSH1在50摄氏度时具有高细胞表面疏水性和降解不同烃类的能力，这可能使其成为处理受石油污染的沙漠土壤的理想候选菌株。
