title: Species Divergence vs. Functional Convergence Characterizes Crude Oil Microbial Community Assembly.
abstract: Oil reservoirs exhibit extreme environmental conditions such as high salinity and high temperature. Insights into microbial community assemblages in oil reservoirs and their functional potentials are important for understanding biogeochemical cycles in the subterranean biosphere. In this study, we performed shotgun metagenomic sequencing of crude oil samples from two geographically distant oil reservoirs in China, and compared them with all the 948 available environmental metagenomes deposited in IMG database (until October 2013). Although the dominant bacteria and the proportion of hydrogenotrophic and acetoclastic methanogens were different among oil metagenomes, compared with the metagenomes from other environments, all the oil metagenomes contained higher abundances of genes involved in methanogenic hydrocarbon degradation and stress response systems. In addition, a "shape-sorting" manner was proposed for the assembly of microbial communities in oil reservoirs, with the oil reservoir acting as a function sorter to select microbes with special functions from its endemic pool of microorganisms. At the functional level, we found that environmental metagenomes were generally clustered according to their isolation environments but not their geographical locations, suggesting selective processes to be involved in the assembly of microbial communities based on functional gene composition.
authors: College of Engineering, Peking University, Beijing China.
authors: Yong
authors: Y
authors: Nie
authors: College of Engineering, Peking University, Beijing China.
authors: Jie-Yu
authors: JY
authors: Zhao
authors: College of Architecture and Environment, Sichuan University, Chengdu China.
authors: Yue-Qin
authors: YQ
authors: Tang
authors: College of Engineering, Peking University, Beijing China.
authors: Peng
authors: P
authors: Guo
authors: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing China.
authors: Yunfeng
authors: Y
authors: Yang
authors: College of Engineering, Peking University, BeijingChina; Institute of Engineering (Baotou), College of Engineering, Peking University, BaotouChina.
authors: Xiao-Lei
authors: XL
authors: Wu
authors: Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing China.
authors: Fangqing
authors: F
authors: Zhao
keywords: hydrocarbon degradation; metagenome; methanogenesis; microbial community; oil reservoirs; petroleum