Alk B pyrosequencing -Secondary successional trajectories of structural and catabolic bacterial communities in oil-polluted soil planted with hybrid Poplar

It is envisaged that a detailed understanding of rhizospheric microbial populations will greatly contribute to a better design and implementation of rhizoremediation. In order to investigate the long-term succession of structural and catabolic bacterial communities in oil polluted soil planted with hybrid poplar, we carried out a 2-year field study. Hybrid aspen (Populus tremula x tremuloides) seedlings were planted in polluted soil excavated from an accidental oil-spill site. Vegetated and un-vegetated soil samples were collected for microbial community analyses at 7 different time-points during the course of 2 years and sampling time-points were chosen to cover the seasonal variation in the boreal climate zone. Bacterial community structure was accessed by means of 16S rRNA gene amplicon pyrosequencing whereas catabolic communities were monitored by pyrosequencing of alkane hydroxylase and extradiol dioxygenase genes. We observed a clear succession of bacterial communities on both structural and functional levels from early to late phase communities.

人们普遍认为，深入了解根际微生物群落（rhizospheric microbial populations）将极大助力根际修复（rhizoremediation）方案的优化设计与落地实施。为探究杂交杨（hybrid poplar）种植的石油污染土壤中结构性与分解代谢性细菌群落的长期演替规律，本研究开展了为期2年的野外研究。实验所用污染土壤采自某意外溢油事故现场，将欧洲山杨×美洲山杨（Populus tremula × tremuloides）杂交杨幼苗定植于该污染土壤中。在为期2年的实验周期内，于7个不同时间节点分别采集种植区与裸地土壤样品用于微生物群落分析，采样节点的选取覆盖了北方气候区的季节变化特征。细菌群落结构通过16S rRNA基因扩增子焦磷酸测序（16S rRNA gene amplicon pyrosequencing）进行解析，而分解代谢群落则通过烷烃羟化酶（alkane hydroxylase）与外二醇双加氧酶（extradiol dioxygenase）基因的焦磷酸测序进行监测。本研究观察到，细菌群落在结构与功能层面均呈现出从早期群落到晚期群落的清晰演替过程。