Department of Civil Engineering, Auburn University, Auburn, AL 36849, USA.
Environ Sci Process Impacts. 2013 Oct;15(11):2068-79. doi: 10.1039/c3em00200d.
We investigated the impact of the Deepwater Horizon oil spill on microbial communities in wetland sediment and seawater samples collected from sites along the Gulf shore. Based on GC/MS analysis, the sediment from Bay Jimmy, LA had detectable signs of hydrocarbon contamination, identified as n-alkanes in the GC/MS spectrum similar to that of the Deepwater Horizon source oil (MC-252). To identify changes in microbial assemblage structure and functional diversity in response to hydrocarbon contamination, five genes (bacterial 16S rRNA, Pseudomonas-specific 16S rRNA, alkB, P450, and PAH-RHDα) were selected based on the specific enzymes encoded by bacteria to degrade alkanes or polycyclic aromatic hydrocarbons. A quantitative PCR analysis revealed the presence of alkane and PAH-degrading genes in both contaminated and non-contaminated samples with no significant difference in gene content between contaminated and non-contaminated samples. However, the ribotype analysis based on pyrosequencing identified 17 bacteria genera known for their capacity to degrade hydrocarbons, including Mycobacterium, Novosphingobium, Parvibaculum, Pseudomonas, and Sphingomonas, in the contaminated sediment sample. Furthermore, the contaminated sample had a very high relative abundance of 16S rRNA gene sequences affiliated with the genus Parvibaculum, members of which have been characterized for their degradative abilities. These data suggest that specific bacterial taxa within the genus Parvibaculum have the capacity for hydrocarbon degradation and could use the hydrocarbons as a carbon and energy source, resulting in a dominant population in a hydrocarbon-contaminated soil. In summary, when exposed to the spilled oil, the distinct wetland microbial communities responded with decreased diversity and increased abundance of selective degradative species.
我们调查了墨西哥湾沿岸湿地沉积物和海水样本中微生物群落受深海地平线（Deepwater Horizon）石油泄漏的影响。基于 GC/MS 分析，LA 的 Bay Jimmy 的沉积物有可检测到的碳氢化合物污染迹象，GC/MS 谱中鉴定出类似于深海地平线源油（MC-252）的正构烷烃。为了确定微生物群落结构和功能多样性对碳氢化合物污染的响应变化，选择了五个基因（细菌 16S rRNA、假单胞菌特异性 16S rRNA、alkB、P450 和 PAH-RHDα），这些基因是根据细菌编码的特定酶来降解烷烃或多环芳烃而选定的。定量 PCR 分析显示，受污染和未受污染的样品中都存在烷烃和 PAH 降解基因，受污染和未受污染的样品之间基因含量没有显著差异。然而，基于焦磷酸测序的核糖体型分析鉴定出 17 个已知具有降解碳氢化合物能力的细菌属，包括分枝杆菌属、新鞘氨醇单胞菌属、Parvibaculum 属、假单胞菌属和鞘氨醇单胞菌属，在受污染的沉积物样品中。此外，受污染的样品中 Parvibaculum 属的 16S rRNA 基因序列相对丰度非常高，该属的成员因其降解能力而被描述。这些数据表明，Parvibaculum 属内的特定细菌类群具有降解碳氢化合物的能力，并可能将碳氢化合物作为碳和能源来源，导致在碳氢化合物污染土壤中占优势。总之，当暴露于溢出的石油时，独特的湿地微生物群落的反应是多样性降低，选择性降解物种的丰度增加。
