RAPID: Response to the MTBE Spill, Port of Houston, Texas, March 2015

3月9日，两艘船在休斯顿港航道相撞。载有21.6万桶甲基叔丁基醚（MTBE）的卡拉·马士基号（Carla Maersk）破裂，估计有20万加仑MTBE泄漏到休斯顿港。MTBE极易溶于水，一两天内就没有可见的光泽。因此，放置疏水撇油栏的“表面响应”不包含MTBE，并且可能在通道内稀释和分散大量MTBE。标准的“溢油”响应不太可能减弱MTBE，本研究将为休斯顿港的利益相关者提供数据，以协助短期和长期响应。拟议工作的总体目标是描述微生物群落如何对海洋沉积物中的MTBE污染作出反应，并确定在有或没有工程干预的情况下会减弱MTBE的特定微生物过程。这是第一次可以从一开始就跟踪泄漏，这些数据将有助于未来所有与MTBE补救和大规模泄漏响应相关的工作。具体目标是：1)使用宏基因组测序和高通量16S rRNA基因测序来确定微生物种群的变化，以及与MTBE泄漏相关的微生物活动；2)量化天然MTBE衰减率，并确定可以增加生物降解速度和程度的过程。这些目标将通过测试以下假设来实现：1)微生物群落将随着MTBE的变化而发生变化，并由先前在MTBE降解富集培养和沉积物培养中确定的可操作的分类单位主导；2)硫酸盐还原微生物将主导所有MTBE降解微生物反应。该研究将使用从休斯顿港海洋沉积物中提取的微生物DNA的高通量测序，以表征微生物种群对MTBE污染的反应。此外，PI将使用标准的缺氧间歇培养来确定MTBE降解的速率和程度，并通过分析已知的中间体，如叔丁醇和甲酸叔丁基，来预测生物降解的途径。所有缺氧培养技术以前都有报道，将是标准的缺氧，用丁基橡胶塞密封的玻璃血清瓶，用缺氧气体冲洗注射器和针头装置取样。建议的活动将在响应者和实践者两级感受到。这些数据可以并将用于协助所有未来大型MTBE泄漏的工程响应。此外，基础科学数据可用于识别对MTBE有反应并可能降解MTBE的特定微生物种群。

1542727FinneranOn March 9 two ships collided in the Port of Houston shipping lane. The Carla Maersk, which was carrying 216,000 barrels of methyl tertiary-butyl ether (MTBE), was ruptured and an estimated 200,000 gallons of MTBE leaked into the Port of Houston. MTBE is extremely water soluble, and visible sheens were absent within a day or two. Therefore, the "surface response" of placing hydrophobic oil skimming booms did not contain the MTBE, and a large volume likely diluted and dispersed within the channel. It is unlikely that standard "oil spill" responses will attenuate MTBE, and this research will provide the Port of Houston stakeholders with data to assist in the short and long term response.The broad objective of the proposed work is to characterize how the microbial community responds to MTBE contamination in marine sediment, and to identify specific microbial processes that will attenuate MTBE with or without engineering intervention. This is the first time a spill can be tracked from its inception, and the data will assist in all future efforts related to both MTBE remediation and high volume spill response. The specific objectives are to: 1) use metagenomic sequencing and high throughput 16S rRNA gene sequencing to determine both the shifts in microbial populations, as well as microbial activity related to the MTBE spill, and 2) quantify the native MTBE attenuation rates, and identify processes that can increase the rate and extent of biodegradation. These objectives will be met by testing the following hypotheses: 1) The microbial community will shift in response to MTBE and be dominated by operable taxonomic units previously identified in MTBE-degrading enrichment cultures and sediment incubations; and, 2) Sulfate-reducing microorganisms will dominate all MTBE degrading microbial reactions. The research will use high throughput sequencing of microbial DNA extracted from marine sediment in the Port of Houston to characterize the shift amongst microbial populations as they respond to MTBE contamination. In addition, the PI will use standard anoxic batch incubations to determine the rate and extent of MTBE degradation, and the projected pathway of biodegradation by analyzing known intermediates such as tert-butyl alcohol and tert-butyl formate. All anoxic incubation techniques have been previously reported and will be standard anoxic, glass serum bottles sealed with a butyl rubber stopper and sampled with anoxic-gas flushed syringe and needle setups. The proposed activity will be felt at the responder and practitioner levels. These data can and will be used to assist all future engineering responses to large MTBE spills. In addition, the basic scientific data can be used to identify specific microbial populations that respond to and possibly degrade MTBE.