The use of novel high‐throughput sequencing (HTS) technologies to examine the responses of natural multidomain microbial communities to scrubber effluent discharges to the marine environment is still limited. Thus, we applied metabarcoding sequencing targeting the planktonic unicellular eukaryotic and prokaryotic fraction (phytoplankton, bacterioplankton, and protozooplankton) in mesocosm experiments with natural microbial communities from a polluted and an unpolluted site. Furthermore, metagenomic analysis revealed changes in the taxonomic and functional dominance of multidomain marine microbial communities after scrubber effluent additions. The results indicated a clear shift in the microbial communities after such additions, which favored bacterial taxa with known oil and polycyclic aromatic hydrocarbons (PAHs) biodegradation capacities. These bacteria exhibited high connectedness with planktonic unicellular eukaryotes employing variable trophic strategies, suggesting that environmentally relevant bacteria can influence eukaryotic community structure. Furthermore, Clusters of Orthologous Genes associated with pathways of PAHs and monocyclic hydrocarbon degradation increased in numbers at treatments with high scrubber effluent additions acutely. These genes are known to express enzymes acting at various substrates including PAHs. These indications, in combination with the abrupt decrease in the most abundant PAHs in the scrubber effluent below the limit of detection—much faster than their known half‐lives—could point toward a bacterioplankton‐initiated rapid ultimate biodegradation of the most abundant toxic contaminants of the scrubber effluent. The implementation of HTS could be a valuable tool to develop multilevel biodiversity indicators of the scrubber effluent impacts on the marine environment, which could lead to improved impact assessment. Environ Toxicol Chem 2024;00:1–18. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

中文翻译：

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在群落结构和功能端点评估海洋微生物群对航运洗涤器废水的反应

使用新型高通量测序（HTS）技术来检查天然多域微生物群落对洗涤器废水排放到海洋环境的反应仍然有限。因此，我们在污染和未污染地点的天然微生物群落的中生态实验中应用了针对浮游单细胞真核生物和原核生物部分（浮游植物、浮游细菌和原生动物）的元条形码测序。此外，宏基因组分析揭示了添加洗涤塔废水后，多域海洋微生物群落的分类和功能优势发生了变化。结果表明，添加此类物质后，微生物群落发生了明显的变化，有利于具有已知石油和多环芳烃 (PAH) 生物降解能力的细菌类群。这些细菌表现出与采用可变营养策略的浮游单细胞真核生物的高度关联性，表明环境相关细菌可以影响真核群落结构。此外，在洗涤器废水添加量高的处理中，与多环芳烃和单环烃降解途径相关的直系同源基因簇的数量急剧增加。已知这些基因表达作用于包括多环芳烃在内的各种底物的酶。这些迹象，再加上洗涤器流出物中最丰富的多环芳烃突然减少到检测限以下（比其已知的半衰期快得多），可能表明浮游细菌引发了最丰富的有毒污染物的快速最终生物降解。洗涤器废水。HTS 的实施可以成为制定洗涤器废水对海洋环境影响的多层次生物多样性指标的宝贵工具，从而可以改进影响评估。环境毒理化学2024；00：1–18。© 2024 作者。环境毒理学和化学由 Wiley periodicals LLC 代表 SETAC 出版。