Department of Renewable Resources, University of Alberta, Edmonton, Alberta T6G 2E3, Canada.
Environ Sci Technol. 2011 Jul 1;45(13):5892-9. doi: 10.1021/es200649t. Epub 2011 Jun 6.
Extraction of bitumen from mined oil sands ores produces enormous volumes of tailings that are stored in settling basins (current inventory ≥ 840 million m(3)). Our previous studies revealed that certain hydrocarbons (short-chain n-alkanes [C(6)-C(10)] and monoaromatics [toluene, o-xylene, m-xylene]) in residual naphtha entrained in the tailings are biodegraded to CH(4) by a consortium of microorganisms. Here we show that higher molecular weight n-alkanes (C(14), C(16), and C(18)) are also degraded under methanogenic conditions in oil sands tailings, albeit after a lengthy lag (~180 d) before the onset of methanogenesis. Gas chromatographic analyses showed that the longer-chain n-alkanes each added at ~400 mg L(-1) were completely degraded by the resident microorganisms within ~440 d at ~20 °C. 16S rRNA gene sequence analysis of clone libraries implied that the predominant pathway of longer-chain n-alkane metabolism in tailings is through syntrophic oxidation of n-alkanes coupled with CO(2) reduction to CH(4). These studies demonstrating methanogenic biodegradation of longer-chain n-alkanes by microbes native to oil sands tailings may be important for effective management of tailings and greenhouse gas emissions from tailings ponds.
从开采的油砂矿石中提取沥青会产生大量的尾矿，这些尾矿被储存在沉降池中（目前的库存≥8.4 亿立方米）。我们之前的研究表明，残留在尾砂中的某些碳氢化合物（短链正烷烃[C(6)-C(10)]和单芳烃[甲苯、邻二甲苯、间二甲苯]）会被微生物群落生物降解为 CH(4)。在这里，我们表明在油砂尾矿的产甲烷条件下，高分子量的正烷烃（C(14)、C(16)和 C(18)）也会被降解，尽管在产甲烷作用开始之前会有很长的滞后期（~180 天）。气相色谱分析表明，每个添加浓度约为 400mg/L 的长链正烷烃在约 20°C 下约 440 天内被土著微生物完全降解。克隆文库的 16S rRNA 基因序列分析表明，尾砂中长链正烷烃代谢的主要途径是通过与 CO(2)还原为 CH(4)偶联的微生物共氧化。这些研究表明，油砂尾矿中的微生物可以对长链正烷烃进行产甲烷生物降解，这对于尾矿的有效管理和尾矿池温室气体排放可能非常重要。
