Natural Sunlight Shapes Crude Oil-Degrading Bacterial Communities in Northern Gulf of Mexico Surface Waters.
Natural Sunlight Shapes Crude Oil-Degrading Bacterial Communities in Northern Gulf of Mexico Surface Waters.
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DOI：
10.3389/fmicb.2015.01325
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发表时间：
2015
影响因子：
5.2
通讯作者：
Erdner DL
中科院分区：
文献类型：
--
作者：
Bacosa HP;Liu Z;Erdner DL
继2010年深水地平线(DWH)漏油事件后，在墨西哥湾北部的深水和表层水域观察到了大量的石油。地表水的特点是夏季阳光强烈，温度高。虽然深海羽流中的石油降解细菌群落已经得到了广泛的调查，但自然阳光对受石油污染的地表水域中石油降解细菌群落的影响至今仍未被探索。在这项研究中，我们在墨西哥湾北部的自然阳光下，将来自DWH站点的地表水与原油和/或Corexit分散剂的改进剂孵化36天。通过焦解测序分析细菌群落的总丰度、烷烃和多环芳烃降解物的密度以及群落组成。我们的结果表明，对于石油和/或Corexit处理，阳光显著降低了细菌多样性和均匀性，是细菌群落结构变化的关键驱动因素。在含有油或分散剂的样品中，阳光极大地降低了蓝藻聚球藻的丰度，但增加了Alteromonas、Marinbacter、Labrenzia、Sandarakinotalae、Bartonella和Halomonas的相对丰度。含油的深色样品由海藻属、Winogradsky ella属、Alcanivorax属、台塑沙属、假单胞菌属、真细菌属、红杆菌属、Natronocella属和Coxiella属的成员组成。无论有无阳光照射，油和Corexit均能抑制假丝酵母菌生长。我们首次演示了光在含有石油和/或Corexit的水中构建微生物群落的效果。总体而言，我们的发现提高了对地表水中石油污染的理解，并提供了明确的证据，表明阳光是决定受石油污染的海水中细菌群落组成和动态的关键因素。
Following the Deepwater Horizon (DWH) spill in 2010, an enormous amount of oil was observed in the deep and surface waters of the northern Gulf of Mexico. Surface waters are characterized by intense sunlight and high temperature during summer. While the oil-degrading bacterial communities in the deep-sea plume have been widely investigated, the effect of natural sunlight on those in oil polluted surface waters remains unexplored to date. In this study, we incubated surface water from the DWH site with amendments of crude oil, Corexit dispersant, or both for 36 days under natural sunlight in the northern Gulf of Mexico. The bacterial community was analyzed over time for total abundance, density of alkane and polycyclic aromatic hydrocarbon degraders, and community composition via pyrosequencing. Our results showed that, for treatments with oil and/or Corexit, sunlight significantly reduced bacterial diversity and evenness and was a key driver of shifts in bacterial community structure. In samples containing oil or dispersant, sunlight greatly reduced abundance of the Cyanobacterium Synechococcus but increased the relative abundances of Alteromonas, Marinobacter, Labrenzia, Sandarakinotalea, Bartonella, and Halomonas. Dark samples with oil were represented by members of Thalassobius, Winogradskyella, Alcanivorax, Formosa, Pseudomonas, Eubacterium, Erythrobacter, Natronocella, and Coxiella. Both oil and Corexit inhibited the Candidatus Pelagibacter with or without sunlight exposure. For the first time, we demonstrated the effects of light in structuring microbial communities in water with oil and/or Corexit. Overall, our findings improve understanding of oil pollution in surface water, and provide unequivocal evidence that sunlight is a key factor in determining bacterial community composition and dynamics in oil polluted marine waters.