Wastewater treatment plants (WWTPs) serve as point-source inputs for a variety of nutrients often dominated by nitrogenous compounds as a result of anthropogenic influence. These effluents can impact biogeochemical cycles in freshwater estuaries, influencing microbial communities in both the water and sediment compartments. To assess the impact of point source nutrients, a transect of sediment and pore water samples were collected from 4 locations in the Little River Sub-watershed including locations above and below the Little River Pollution Control Plant (LRPCP). Variation in chemistry and microbial community/gene expression revealed significant influences of the effluent discharge on the adjacent sediments. Phosphorus and sulfur showed high concentrations within plume sediments compared to the reference sediments while nitrate concentrations were low. Increased abundance of denitrifiers Dechloromonas, Dok59 and Thermomonas correlating with increased expression of nitrous-oxide reductase suggests a conversion of N₂O to N₂ within the LRPCP effluent sediments. This study provides valuable insight into the gene regulation of microbes involved in N metabolism (denitrification, nitrification, and nitrite reduction to ammonia) within the sediment compartment influenced by wastewater effluent.

中文翻译：

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调查城市流域沉积物中淡水微生物群落中N ₂ O表达的来源和汇

废水处理厂（WWTP）是人为因素造成的各种营养素的点源输入，这些营养素通常被含氮化合物所控制。这些废水可影响淡水河口的生物地球化学循环，影响水和沉积物区室的微生物群落。为了评估点源养分的影响，从小河子集水区的4个位置（包括小河污染控制厂（LRPCP）上方和下方的位置）收集了沉积物和孔隙水样带。化学和微生物群落/基因表达的变化揭示了污水排放对邻近沉积物的显着影响。与参考沉积物相比，羽状沉积物中的磷和硫含量高，而硝酸盐浓度低。反硝化器数量增加脱氯，Dok59和Thermomonas与亚硝酸氧化物还原酶的表达增加相关暗示N中的一个转换₂ O与N ₂的流出物LRPCP沉积物中。这项研究为受废水排放影响的沉积物室内微生物参与氮代谢（脱氮，硝化和亚硝酸盐还原为氨的微生物）的基因调控提供了有价值的见解。