Biotechnology Department, Faculty of science, University of Tehran, Tehran, Iran.
Appl Microbiol Biotechnol. 2011 Apr;90(1):305-12. doi: 10.1007/s00253-010-3049-6. Epub 2010 Dec 14.
Biodegradation of petroleum compounds in saline environments seems intricate and needs more attention. In this study, tetracosane was used to enrich alkane-degrading bacteria from oil-contaminated saline soils. Among the isolates, strain Qtet3, with the highest 16s rRNA gene sequence similarity to Alcanivorax dieselolei B-5(T), was able to grow at a wide range of NaCl concentrations and was shown by GC analysis to degrade more than 90% of tetracosane in 10 days. This strain has at least two alkB genes and could grow on crude oil and diesel fuel, and utilize various pure aliphatic hydrocarbon substrates (from C(12) to C(34)). Highly hydrophobic cell surfaces and lack of significant surface tension reduction in the media suggest that the main mechanism of the cells for accessing substrate is to attach directly to hydrocarbon particles. Application of this strain for remediating crude oil-contaminated soils irrigated with defined saline water demonstrated that this halotolerant bacterium could survive and grow in saline soils irrigated with NaCl solutions up to 5% w/v, with the highest hydrocarbon degradation of 26.1% observed at 2.5% NaCl. This strain is promising for future industrial applications especially in bioremediation of saline soils and wastes.
在盐环境中，石油化合物的生物降解似乎很复杂，需要更多的关注。在这项研究中，使用二十四烷来从受石油污染的盐土中富集烷烃降解细菌。在分离出的菌株中，与 Alcanivorax dieselolei B-5(T) 具有最高 16s rRNA 基因序列相似性的菌株 Qtet3 能够在广泛的 NaCl 浓度范围内生长，并通过 GC 分析表明，在 10 天内能够降解超过 90%的二十四烷。该菌株至少有两个 alkB 基因，能够在原油和柴油燃料上生长，并利用各种纯脂族烃底物（从 C(12) 到 C(34)）。高度疏水性的细胞表面和培养基中没有显著的表面张力降低表明，细胞获取底物的主要机制是直接附着在烃颗粒上。将该菌株应用于用定义的盐水灌溉的受原油污染土壤的修复中，表明这种耐盐细菌能够在 NaCl 浓度高达 5%（w/v）的盐土中存活和生长，在 2.5%NaCl 下观察到最高的 26.1%烃降解。该菌株有望在未来的工业应用中得到应用，特别是在盐土和废物的生物修复中。
