RAPID:Rates and mechanisms controlling the microbial degradation of crude oil from the MC252 spill in Gulf of Mexico beach sands

在快速反应研究基金（Rapid）的资助下，佛罗里达州立大学的科学家们将研究深水地平线原油在海湾沙滩上的运输和生物降解。该研究将重点放在油过滤引起的沉积物堵塞以及随之而来的本地微生物群落结构和功能的变化上。虽然人们对海滩的石油污染过程进行了详细的研究，但对原油对海滩过滤的影响以及石油相关的海滩孔隙水流减少对沙质沉积物中石油运输和微生物降解的影响知之甚少。这种由波浪形成和潮汐水位变化引起的过滤过程构成了一种有效的泵送机制，可以将低粘度原油和清洁剂-油混合物驱入海滩沉积物深处。石油进入更深的缺氧层可能会降低石油的降解速度，从而延长毒素释放到近岸水域的时间。该项目的目标是评估1)有多少和多深的石油被过滤到海滩，2)石油如何改变海滩的过滤速度，从而改变沉积物的氧化作用，4)石油污染如何改变沙子微生物群落的结构和功能，5)哪些因素调节海洋沙子中微生物群落的石油降解。为了量化这些过程，在墨西哥湾东北部的一个沙滩上，沿着从沿岸上到沿岸下的短样带，每隔一段时间就采集几组沉积物岩心。将分析沉积物的含油量（数量、组成和分布）、沉积物特征（渗透率、孔隙度、粒度谱、氧渗透）和微生物群落（组成和活性）。油将使用GC-MS进行表征。微生物群落组成和活性的变化将通过结合基于培养和不依赖于培养的分子技术进行评估。这些结果将量化海湾沙滩对石油和清洁剂-石油混合物的吸收，这些物质对沉积物物理和生物地球化学性质的影响，沉积微生物群落的反应以及石油降解率。更广泛的影响：墨西哥湾东北部的沙滩是生物栖息地，是大量物种的觅食和繁殖地，是主要的旅游景点，具有很高的生态和经济价值。佛罗里达是旅游业吗？旅游业是美国最大的经济部门，每年约有6000万游客，产值达570亿美元。因此，原油对海滩的污染对佛罗里达州构成了重大威胁？年代的经济。以往的研究表明，石油可以渗透到沙滩深处，这可能会改变微生物群落的活动，降低石油的降解速度。后果包括毒素从这些海滩释放持续多年。了解墨西哥湾沙滩上石油的吸收、运输和降解是设计清理和补救程序的先决条件。该项目的研究重点是墨西哥湾的原始海滩，那里没有石油渗透和退化的数据，现在受到深水地平线灾难的威胁。该项目将研究与两名研究生的教育和培训相结合。项目结果将在科学期刊、当地媒体和互联网上发表。在这个快速反应项目中收集的数据将为一个为期三年的项目提案提供数据，该项目的重点是可渗透海岸沉积物中原油成分的运输和降解。该项目的目标是产生定量数据，以便预测石油降解过程和优化生物修复程序。

With funding through this Grant for Rapid Response Research (RAPID), scientists at the Florida State University will study the transport and biodegradation of Deepwater Horizon crude oil in Gulf beach sands. The study will place emphasis on the sediment clogging caused by oil filtration and ensuing changes to the structure and function of indigenous microbial communities. Although the process of oil contamination of beaches has been investigated in great detail, little is known about the effect of crude oil on beach filtration and the effect of oil-related reduction of beach pore water flows on oil transport and microbial degradation within the sandy sediment. This filtration process, caused by wave set up and tidal water level changes, constitutes an effective pumping mechanism that can drive low-viscosity crude oil and detergent-oil mixtures deep into beach sediments. Oil transport into deeper, anoxic layers may decrease oil degradation rates, thereby extending the period of toxin release to nearshore waters. Goals of the project are to assess 1) how much and how deep oil is filtered into the beach, 2) how oil alters the beach filtration rate and thereby sediment oxygenation, 4) how oil contamination changes structure and function of the sand microbial community and 5) which factors regulate oil degradation by microbial communities in marine sands.To quantify these processes, sets of sediment cores will be taken at time intervals along a short transect from the supralittoral to the sublittoral zone at a sandy beach in the Northeastern Gulf of Mexico. The sediment will be analyzed for oil content (amount, composition and distribution), sediment characteristics (permeability, porosity, grain size spectrum, oxygen penetration), and the microbial community (composition and activity). Oil will be characterized using a GC-MS. Changes in microbial community composition and activity will be assessed using a combination of culture-based and cultivation-independent molecular techniques. The results will quantify the uptake of oil and detergent-oil mixtures into Gulf sand beaches, the effect of these substances on sediment physical and biogeochemical properties, the response of the sedimentary microbial community, and oil degradation rates. Broader Impacts: The sandy beaches of the Northeastern Gulf of Mexico are of high ecological and economical value as they are biotope, foraging and breeding area of a large number species, and present a main tourist attraction. Tourism is Florida?s largest sector of the state economy with about 60 million visitors every year and a $57 billion impact. The pollution of the beaches by crude oil thus presents a major threat to Florida?s economy. Previous research indicates that oil can penetrate deep into sandy beaches, which may change microbial community activities and decrease the oil degradation rates. Consequences include toxin release from such beaches extending over many years. Understanding the uptake, transport and degradation of oil in sandy Gulf beaches is prerequisite for designing clean up and remediation procedures. Research of this project focuses on pristine Gulf beaches for which no data on oil penetration and degradation exist and that now are threatened by the Deepwater Horizon disaster. The project combines research with education and training of two graduate students. Project results will be published in scientific journals, local outlets and the internet. The data collected in this rapid response project will provide data for a proposal of a three year project focusing on transport and degradation of crude oil components in permeable shore sediments. The project goal is to generate quantitative data that permit forecasting of the oil degradation process and optimization of bioremediation procedures.