RAPID: Impact of Nutrient Limitation on Microbial Degradation of Deepwater Horizon Oil in the Gulf of Mexico

天然微生物降解在原油释放到海洋环境的修复中起着重要作用。“深水地平线”漏油事件的一个重要特征可能会限制微生物的降解速度，那就是漏油所处的水域的可用营养物质已经高度枯竭；微生物需要这些营养物来生长和降解油。尽管自20世纪80年代以来，对石油降解的N和P限制的研究相对较少，但在此期间，我们在评估海水中微生物的特性、活性和营养限制状况方面取得了重大进展；早期的大部分工作都集中在简单地追踪石油随时间的消失，但现在我们有能力同时监测微生物群落的行为。在快速反应研究基金（Rapid）的资助下，伍兹霍尔海洋研究所的微生物生物地球化学家团队将研究溢油中微生物异养、营养物质和石油化合物如何相互作用。他们认为，由于“深水地平线”漏油事故造成的营养物质限制可能会影响石油的降解，因此有必要立即使用最新的微生物和分子方法对墨西哥湾的这一问题进行有针对性的评估。这项研究将实现三个目标：1)评估墨西哥湾的微生物受到深水地平线石油污染区域内外营养物质缺乏的压力程度；2)研究营养胁迫与深水地平线原油微生物降解速率的关系；3)明确确定卵磷脂（一种植物来源的、无毒的、疏水的含N和p的有机营养物）是否刺激了油的降解速率。深水地平线漏油事件是一个具有历史意义的事件，有可能对我们国家的环境质量和经济竞争力产生严重的负面影响。这项工作的主要好处是揭示了微生物油降解的潜在生物地球化学障碍，这些障碍可能通过新的补救措施来克服。此外，通过执行首席研究员在2002年收集的测量数据，该项目还将获得第二个好处，即识别将在整个食物网传播的磷场扰动，包括墨西哥湾的渔业。

Natural microbial degradation plays an important role in the remediation of crude oil released to the marine environment. One important characteristic of the Deepwater Horizon oil release that could limit microbial degradation rates is that the oil is surfacing in waters that are highly depleted in available nutrients; microbes need these nutrients in order to grow and degrade oil. Although there have been comparatively few studies on N and P limitation of oil degradation since the 1980s, in the intervening time there have been major advances in our ability to assess the identity, activity and nutrient-limitation status of microbes in seawater; most of the early work centered on simply tracking the disappearance of oil over time, but now we have the ability to monitor the behavior of the microbial community in parallel. With funding through this Grant for Rapid Response Research (RAPID), a team of microbial biogeochemists at the Woods Hole Oceanographic Institution will examine how microbial heterotrophy, nutrients, and petroleum compounds in the oil spill interact. They posit that the obvious potential for nutrient limitation to impact the degradation of oil from the Deepwater Horizon release warrants an immediate, targeted assessment of this issue in the Gulf of Mexico using up-to-date microbial and molecular methods. The study will achieve three objectives: 1) assess the degree to which microbes in the Gulf of Mexico are stressed by the unavailability of nutrients both inside and outside of areas contaminated by Deepwater Horizon oil; 2) examine the relationship between nutrient stress and the microbial degradation rate of Deepwater Horizon oil; 3) specifically determine whether oil degradation rates are stimulated by lecithin, a plant-derived, non-toxic, hydrophobic N- and P-containing organic nutrient. Broader impacts The Deepwater Horizon oil release is an event of historic significance that has the potential to severely negatively impact the environmental quality and economic competitiveness of our nation. The primary benefit of the proposed work will be to reveal potential biogeochemical barriers to microbial oil degradation that might be overcome through novel remediation efforts. In addition, by conducting measurements collected by the lead investigator in 2002, the project will have the secondary benefit of identifying perturbations in the phosphorous field that will be propagated throughout the food web, including Gulf of Mexico fisheries.