Rodriguez-R Luis M, Overholt Will A, Hagan Christopher, Huettel Markus, Kostka Joel E, Konstantinidis Konstantinos T
School of Biology, Georgia Institute of Technology, Atlanta, GA, USA.
Department of Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, USA.
ISME J. 2015 Sep;9(9):1928-40. doi: 10.1038/ismej.2015.5. Epub 2015 Feb 17.
Although petroleum hydrocarbons discharged from the Deepwater Horizon (DWH) blowout were shown to have a pronounced impact on indigenous microbial communities in the Gulf of Mexico, effects on nearshore or coastal ecosystems remain understudied. This study investigated the successional patterns of functional and taxonomic diversity for over 1 year after the DWH oil was deposited on Pensacola Beach sands (FL, USA), using metagenomic and 16S rRNA gene amplicon techniques. Gamma- and Alphaproteobacteria were enriched in oiled sediments, in corroboration of previous studies. In contrast to previous studies, we observed an increase in the functional diversity of the community in response to oil contamination and a functional transition from generalist populations within 4 months after oil came ashore to specialists a year later, when oil was undetectable. At the latter time point, a typical beach community had reestablished that showed little to no evidence of oil hydrocarbon degradation potential, was enriched in archaeal taxa known to be sensitive to xenobiotics, but differed significantly from the community before the oil spill. Further, a clear succession pattern was observed, where early responders to oil contamination, likely degrading aliphatic hydrocarbons, were replaced after 3 months by populations capable of aromatic hydrocarbon decomposition. Collectively, our results advance the understanding of how natural benthic microbial communities respond to crude oil perturbation, supporting the specialization-disturbance hypothesis; that is, the expectation that disturbance favors generalists, while providing (microbial) indicator species and genes for the chemical evolution of oil hydrocarbons during degradation and weathering.
尽管从“深水地平线”(DWH)井喷中排放的石油碳氢化合物已被证明对墨西哥湾的本土微生物群落有显著影响,但对近岸或沿海生态系统的影响仍研究不足。本研究利用宏基因组学和16S rRNA基因扩增技术,调查了DWH石油沉积在美国佛罗里达州彭萨科拉海滩沙子上一年多后功能和分类多样性的演替模式。γ-变形菌纲和α-变形菌纲在受油污染的沉积物中富集,这与之前的研究结果一致。与之前的研究不同,我们观察到群落的功能多样性因油污而增加,并且在石油上岸后4个月内,群落功能从通才种群转变为一年后的专性种群,此时已检测不到石油。在后一个时间点,一个典型的海滩群落重新建立起来,几乎没有显示出石油碳氢化合物降解潜力的证据,富含已知对异生素敏感的古菌类群,但与溢油前的群落有显著差异。此外,还观察到一个清晰的演替模式,即对油污的早期响应者(可能降解脂肪族碳氢化合物)在3个月后被能够分解芳香族碳氢化合物的种群取代。总体而言,我们的结果推进了对天然底栖微生物群落如何响应原油扰动的理解,支持了专业化-干扰假说;也就是说,干扰有利于通才的预期,同时为石油碳氢化合物在降解和风化过程中的化学演化提供(微生物)指示物种和基因。