Georgia Institute of Technology, Schools of Biology and Earth and Atmospheric Sciences, Room 225, Cherry Emerson Bldg., 310 Ferst Dr., Atlanta, GA 30332-0230, USA.
Appl Environ Microbiol. 2011 Nov;77(22):7962-74. doi: 10.1128/AEM.05402-11. Epub 2011 Sep 23.
A significant portion of oil from the recent Deepwater Horizon (DH) oil spill in the Gulf of Mexico was transported to the shoreline, where it may have severe ecological and economic consequences. The objectives of this study were (i) to identify and characterize predominant oil-degrading taxa that may be used as model hydrocarbon degraders or as microbial indicators of contamination and (ii) to characterize the in situ response of indigenous bacterial communities to oil contamination in beach ecosystems. This study was conducted at municipal Pensacola Beach, FL, where chemical analysis revealed weathered oil petroleum hydrocarbon (C₈ to C₄₀) concentrations ranging from 3.1 to 4,500 mg kg⁻¹ in beach sands. A total of 24 bacterial strains from 14 genera were isolated from oiled beach sands and confirmed as oil-degrading microorganisms. Isolated bacterial strains were primarily Gammaproteobacteria, including representatives of genera with known oil degraders (Alcanivorax, Marinobacter, Pseudomonas, and Acinetobacter). Sequence libraries generated from oiled sands revealed phylotypes that showed high sequence identity (up to 99%) to rRNA gene sequences from the oil-degrading bacterial isolates. The abundance of bacterial SSU rRNA gene sequences was ∼10-fold higher in oiled (0.44 × 10⁷ to 10.2 × 10⁷ copies g⁻¹) versus clean (0.024 × 10⁷ to 1.4 × 10⁷ copies g⁻¹) sand. Community analysis revealed a distinct response to oil contamination, and SSU rRNA gene abundance derived from the genus Alcanivorax showed the largest increase in relative abundance in contaminated samples. We conclude that oil contamination from the DH spill had a profound impact on the abundance and community composition of indigenous bacteria in Gulf beach sands, and our evidence points to members of the Gammaproteobacteria (Alcanivorax, Marinobacter) and Alphaproteobacteria (Rhodobacteraceae) as key players in oil degradation there.
墨西哥湾近期深水地平线（DH）溢油事件的大量溢油被运移到了海岸线，这可能会对生态和经济产生严重影响。本研究的目的是：(i) 鉴定和描述主要的石油降解类群，这些类群可作为模型烃类降解菌或作为污染的微生物指示物；(ii) 描述海滩生态系统中土著细菌群落对石油污染的原位响应。本研究在佛罗里达州彭萨科拉海滩市进行，化学分析表明，海滩砂中风化石油的石油烃（C₈ 到 C₄₀）浓度范围为 3.1 至 4500mgkg⁻¹。从受污染的海滩砂中分离出 24 株来自 14 个属的细菌菌株，并证实它们是石油降解微生物。分离出的细菌菌株主要为γ-变形菌，包括已知的石油降解菌（Alcanivorax、Marinobacter、Pseudomonas 和 Acinetobacter）的代表属。从污染砂中生成的序列文库揭示了与石油降解细菌分离株的 rRNA 基因序列具有高相似性（高达 99%）的类群。与清洁砂（0.024×10⁷ 到 1.4×10⁷ 拷贝 g⁻¹）相比，受污染砂（0.44×10⁷ 到 10.2×10⁷ 拷贝 g⁻¹）中细菌 16S rRNA 基因序列的丰度高 10 倍。群落分析表明，对石油污染有明显的响应，并且属 Alcanivorax 的 SSU rRNA 基因丰度在污染样品中增加最大。我们的结论是，DH 溢油事件的石油污染对海湾海滩砂中土著细菌的丰度和群落组成产生了深远影响，并且我们的证据表明，γ-变形菌（Alcanivorax、Marinobacter）和α-变形菌（Rhodobacteraceae）的成员是那里石油降解的关键参与者。
