Dashti N, Al-Awadhi H, Khanafer M, Abdelghany S, Radwan S
Department of Biological Sciences, Faculty of Science, Kuwait University, PO Box 5969, Safat 13060, Kuwait.
Chemosphere. 2008 Jan;70(3):475-9. doi: 10.1016/j.chemosphere.2007.06.052. Epub 2007 Aug 1.
Bacteria and fungi in pristine and oily desert soil samples were counted on inorganic medium aliquots containing 0.5% hexadecane, hexadecanol, hexadecanal or hexadecanoic acid, as sole sources of carbon and energy. It was found that the carbon and energy source most commonly utilized by soil bacteria was the alkane n-hexadecane, and by soil fungi hexadecanoic acid. Representative microorganisms were isolated and identified. The most predominant bacteria in all soil samples belonged to the genera Micrococcus and Pseudomonas; less dominant bacteria belonged to the group of nocardioforms. The most frequent fungal genera were Aspergillus and Penicillium, while Microsporium and Ulocladium were minor fungi. Irrespective of the substrate on which the microbial strains had initially been isolated, the majority of the isolated microorganisms could grow, albeit to a varying degree, on an inorganic medium containing any of the remaining three substrates as sole carbon and energy sources. Bacterial strains preferred the alkane as a carbon and energy source over any of its oxidation products, while fungal strains preferred to grow mainly on the fatty acids. Quantitative analysis by gas liquid chromatography revealed that the predominant bacterial and fungal isolates had a potential for the attenuation of the alkane and its immediate oxidation products in the medium. In view of the continuous release of hydrocarbon oxidation products by oil-utilizing microorganisms in oily environments, it is interesting that the indigenous microflora contribute to the uptake and utilization of all such intermediate compounds, thus, having a potential for efficient self-cleaning and bioremediation of oily soils.
对原始沙漠土壤样本和含油沙漠土壤样本中的细菌和真菌进行计数，计数采用的无机培养基等分试样含有0.5%的十六烷、十六醇、十六醛或十六酸，这些物质作为唯一的碳源和能源。结果发现，土壤细菌最常利用的碳源和能源是正十六烷，而土壤真菌最常利用的是十六酸。分离并鉴定了具有代表性的微生物。所有土壤样本中最主要的细菌属于微球菌属和假单胞菌属；不太占优势的细菌属于诺卡氏菌型菌群。最常见的真菌属是曲霉属和青霉属，而小孢子菌属和枝孢属是次要真菌。无论最初分离微生物菌株时使用的底物是什么，大多数分离出的微生物都能够在含有其余三种底物中任何一种作为唯一碳源和能源的无机培养基上生长，尽管生长程度有所不同。细菌菌株优先选择烷烃作为碳源和能源，而不是其任何氧化产物，而真菌菌株则主要偏好以脂肪酸为碳源生长。气相色谱定量分析表明，主要的细菌和真菌分离株具有在培养基中降解烷烃及其直接氧化产物的潜力。鉴于在含油环境中利用石油的微生物会持续释放烃类氧化产物，有趣的是，本地微生物群落有助于摄取和利用所有此类中间化合物，因此具有对含油土壤进行高效自我清洁和生物修复的潜力。
