Department of Environmental Chemistry, IDAEA-CSIC, Barcelona, Catalunya, Spain.
Department of Marine Biology and Oceanography, ICM-CSIC, Barcelona, Catalunya, Spain.
Sci Total Environ. 2019 Aug 15;678:486-498. doi: 10.1016/j.scitotenv.2019.04.361. Epub 2019 Apr 27.
Organic pollutants are continuously being introduced in seawater with uncharacterized impacts on the engines of the marine biogeochemical cycles, the microorganisms. The effects on marine microbial communities were assessed for perfluoroalkyl substances, organophosphate esters flame retardants and plasticizers, polycyclic aromatic hydrocarbons, and n-alkanes. Dose-response experiments were performed at three stations and at three depths in the NW Mediterranean with contrasted nutrient and pollutant concentrations. In these experiments, the microbial growth rates, the abundances of the main bacterial groups, measured by Catalyzed Reporter Deposition Fluorescence In Situ Hybridization (CARD-FISH), and extracellular enzymatic activities, were quantified. Increasing concentrations of organic pollutants (OPs) promoted different responses in the communities that were compound, organism and nutrient availability (trophic status). The largest differences between OP treatments and controls in the growth rates of both heterotrophic and phototrophic microbial groups were observed in seawater from the deep chlorophyll maxima. Furthermore, there was a compound specific stimulation of different extracellular enzymatic activities after the exposure to OPs. Our results revealed that marine microbial communities reacted not only to hydrocarbons, known to be used as a carbon source, but also to low concentrations of organic pollutants of emerging concern in a complex manner, reflecting the variability of various environmental variables. Multiple linear regressions suggested that organic pollutants modulated the bacterial growth and extracellular enzymatic activities, but this modulation was of lower magnitude than the observed pronounced response of the microbial community to nutrient availability.
有机污染物不断被引入海水中，对海洋生物地球化学循环的引擎——微生物产生了特征不明的影响。本研究评估了全氟烷基物质、有机磷酸酯阻燃剂和增塑剂、多环芳烃和正构烷烃对海洋微生物群落的影响。在西北地中海的三个站位和三个深度进行了剂量-反应实验，这些站位的营养物和污染物浓度存在差异。在这些实验中，通过 Catalyzed Reporter Deposition Fluorescence In Situ Hybridization (CARD-FISH) 测量了微生物生长率、主要细菌群的丰度以及细胞外酶活性。有机污染物 (OPs) 浓度的增加促进了群落的不同反应，这些反应与化合物、生物体和营养物可利用性（营养状态）有关。在深层叶绿素最大值的海水中，观察到 OPs 处理组与对照组在异养和自养微生物群体的生长率方面的差异最大。此外，在暴露于 OPs 后，不同细胞外酶活性也出现了特定的化合物刺激。我们的结果表明，海洋微生物群落不仅对烃类（已知可用作碳源）做出反应，而且还以复杂的方式对新兴关注的低浓度有机污染物做出反应，反映了各种环境变量的可变性。多元线性回归表明，有机污染物调节了细菌的生长和细胞外酶活性，但这种调节的幅度低于观察到的微生物群落对营养物可利用性的显著反应。
