Department of Earth and Environmental Sciences and Williamson Research Centre for Molecular Environmental Science, University of Manchester, M13 9PL, UK.
Division of Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 21990, Republic of Korea.
Sci Total Environ. 2024 May 20;926:171813. doi: 10.1016/j.scitotenv.2024.171813. Epub 2024 Mar 20.
Oil spills are a global challenge, contaminating the environment with organics and metals known to elicit toxic effects. Ecosystems within Nigeria's Niger Delta have suffered from prolonged severe spills for many decades but the level of impact on the soil microbial community structure and the potential for contaminant bioremediation remains unclear. Here, we assessed the extent/impact of an oil spill in this area 6 months after the accident on both the soil microbial community/diversity and the distribution of polycyclic aromatic hydrocarbon ring-hydroxylating dioxygenase (PAH-RHDGNα) genes, responsible for encoding enzymes involved in the degradation of PAHs, across the impacted area. Analyses confirmed the presence of oil contamination, including metals such as Cr and Ni, across the whole impacted area and at depth. The contamination impacted on the microbial community composition, resulting in a lower diversity in all contaminated soils. Gamma-, Delta-, Alpha- proteobacteria and Acidobacteriia dominated 16S rRNA gene sequences across the contaminated area, while Ktedonobacteria dominated the non-contaminated soils. The PAH-RHDαGN genes were only detected in the contaminated area, highlighting a clear relationship with the oil contamination/hydrocarbon metabolism. Correlation analysis indicated significant positive relationships between the oil contaminants (organics, Cr and Ni), PAH-RHDαGN gene, and the presence of bacteria/archaea such as Anaerolinea, Spirochaetia Bacteroidia Thermoplasmata, Methanomicrobia, and Methanobacteria indicating that the oil contamination not only impacted the microbial community/diversity present, but that the microbes across the impacted area and at depth were potentially playing an important role in degrading the oil contamination present. These findings provide new insights on the level of oil contamination remaining 6 months after an oil spill, its impacts on indigenous soil microbial communities and their potential for in situ bioremediation within a Niger Delta's ecosystem. It highlights the strength of using a cross-disciplinary approach to assess the extent of oil pollution in a single study.
溢油是一个全球性的挑战，它会将有机物和金属等已知的有毒物质污染环境。几十年来，尼日利亚尼日尔三角洲的生态系统一直受到长期严重溢油的影响，但对土壤微生物群落结构的影响程度以及污染物生物修复的潜力仍不清楚。在这里，我们评估了该地区 6 个月后溢油事故对土壤微生物群落/多样性以及多环芳烃环羟化双加氧酶（PAH-RHDGNα）基因分布的影响，这些基因负责编码参与 PAHs 降解的酶。分析证实了整个受影响地区和深度都存在石油污染，包括铬和镍等金属。污染影响了微生物群落的组成，导致所有污染土壤的多样性降低。γ-、δ-、α-变形菌门和 Acidobacteriia 主导了整个污染区的 16S rRNA 基因序列，而 Ktedonobacteria 则主导了非污染土壤。仅在污染区检测到 PAH-RHDαGN 基因，这突出表明与石油污染/碳氢化合物代谢之间存在明确的关系。相关分析表明，油污染物（有机物、铬和镍）、PAH-RHDαGN 基因与 Anaerolinea、Spirochaetia Bacteroidia Thermoplasmata、Methanomicrobia 和 Methanobacteria 等细菌/古菌之间存在显著的正相关关系，这表明石油污染不仅影响了存在的微生物群落/多样性，而且受影响地区和深度的微生物可能在降解存在的石油污染方面发挥了重要作用。这些发现为溢油 6 个月后残留石油污染的程度、其对本地土壤微生物群落的影响及其在尼日尔三角洲生态系统中就地生物修复的潜力提供了新的见解。它强调了在单个研究中使用跨学科方法评估石油污染程度的优势。
