Identification of microbial communities directly from an Alberta oil sands tailings pond using an in vitro mixed species biofilm dvice and pyrosequencing

To evaluate the microbial population within an oil sands tailings pond, endogenous mixed species biofilms were isolated from the sediments of an oil sands tailings pond. Biofilms were grown using the Calgary Biofilm Device (CBD) under different growth conditions, with and without different growth media. 454 pyrosequencing revealed unique mixed biofilm populations under a specific growth condition, with the dominant population comprising of fermentative microorganisms capable of reducing nitrate (Pseudomonas, Thauera, Hydrogenophaga, and Acidovorax) or iron (Rhodoferax). Our work uses a different approach compared to the traditional biofilm studies and we could demonstrate that mixed species biofilms can be successfully cultivated and identified directly from oil sands tailings. Interestingly, the cultured population closely represented the endogenous environmental population. Thus, our cultivation technique allows isolation and identification of a representative environmental population of mixed species biofilms under laboratory conditions.

为评估油砂尾矿库内的微生物群落，研究人员从油砂尾矿库沉积物中分离得到内源性混合物种生物膜。采用卡尔加里生物膜装置（Calgary Biofilm Device, CBD），在分别添加或不添加不同生长培养基的不同生长条件下培养生物膜。通过454焦磷酸测序（454 pyrosequencing）分析发现，在特定生长条件下存在独特的混合生物膜群落，其优势菌群由两类功能微生物构成：一类为可还原硝酸盐的发酵型微生物，包含假单胞菌属（Pseudomonas）、陶厄氏菌属（Thauera）、氢噬胞菌属（Hydrogenophaga）及食酸菌属（Acidovorax）；另一类为可还原铁的红育菌属（Rhodoferax）。本研究采用区别于传统生物膜研究的实验策略，成功证实可直接从油砂尾矿中培养并鉴定混合物种生物膜。值得注意的是，体外培养得到的菌群与原位环境中的内源性群落高度匹配。因此，本研究建立的培养技术可实现在实验室条件下，分离并鉴定具有代表性的混合物种生物膜环境群落。