Effects of COREXIT® EC9500A on bacteria from a beach oiled by the Deepwater Horizon spill
Effects of COREXIT® EC9500A on bacteria from a beach oiled by the Deepwater Horizon spill
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DOI：
10.3354/ame01482
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发表时间：
2011-01-01
影响因子：
1.4
通讯作者：
Fulmer, Preston A.
中科院分区：
文献类型：
--
作者：
Hamdan, Leila J.;Fulmer, Preston A.
碳氢化合物降解菌对于控制海洋环境中天然和人为碳氢化合物的命运非常重要。在墨西哥湾深水地平线漏油事件发生后，微生物群落对于自然减弱漏油的影响将是重要的。化学分散剂Corexit(R)EC9500A在应对深水地平线事件期间得到了广泛应用。虽然毒性测试证实Corexit(R)EC9500A不会对无脊椎动物和成年鱼类种群构成重大威胁，但关于其对微生物群落的影响的信息有限。我们确定了美国路易斯安那州海滩上因深水地平线漏油而新沉积的石油中微生物群落的组成。在无Corexit(R)EC9500A和存在Corexit(R)EC9500A的情况下，测定从油样中获得的培养物的代谢活性和活力，浓度从0.001到100mgml(-1)。在石油样品的长度异质性PCR指纹图谱中，弧菌含量最高，其次是不动杆菌属和海洋杆菌属的烃类降解菌株。我们观察到，与对照相比，在分散剂存在的情况下，不动杆菌和海洋杆菌的产量和活力显著降低。在被检查的生物体中，海洋杆菌似乎对分散剂最敏感，由于暴露在对泄漏的反应过程中可能遇到的分散剂浓度(1至10 mg ml-1)，其活力和产量几乎100%下降。值得注意的是，在相同的分散剂浓度下，非降解碳氢化合物的弧菌菌株大量繁殖。这些数据表明，碳氢化合物降解菌受到化学分散剂的抑制，分散剂的使用可能会降低环境中生物修复泄漏的能力。
Hydrocarbon-degrading bacteria are important for controlling the fate of natural and anthropogenic hydrocarbons in the marine environment. In the wake of the Deepwater Horizon spill in the Gulf of Mexico, microbial communities will be important for the natural attenuation of the effects of the spill. The chemical dispersant COREXIT (R) EC9500A was widely deployed during the response to the Deepwater Horizon incident. Although toxicity tests confirm that COREXIT (R) EC9500A does not pose a significant threat to invertebrate and adult fish populations, there is limited information on its effect on microbial communities. We determined the composition of the microbial community in oil that had been freshly deposited on a beach in Louisiana, USA, as a result of the Deepwater Horizon spill. The metabolic activity and viability in cultures obtained from oil samples were determined in the absence and presence of COREXIT (R) EC9500A at concentrations ranging from 0.001 to 100 mg ml(-1). In length heterogeneity PCR (LH-PCR) fingerprints of oil samples, the most abundant isolates were those of Vibrio, followed by hydrocarbon-degrading isolates affiliated with Acinetobacter and Marinobacter. We observed significant reductions in production and viability of Acinetobacter and Marinobacter in the presence of the dispersant compared to controls. Of the organisms examined, Marinobacter appears to be the most sensitive to the dispersant, with nearly 100% reduction in viability and production as a result of exposure to concentrations of the dispersant likely to be encountered during the response to the spill (1 to 10 mg ml-1). Significantly, at the same concentration of dispersant, the non-hydrocarbon-degrading Vibrio isolates proliferated. These data suggest that hydrocarbon-degrading bacteria are inhibited by chemical dispersants, and that the use of dispersants has the potential to diminish the capacity of the environment to bioremediate spills.