Benthic Diatom Communities in an Alpine River Impacted by Waste Water Treatment Effluents as Revealed Using DNA Metabarcoding
Benthic Diatom Communities in an Alpine River Impacted by Waste Water Treatment Effluents as Revealed Using DNA Metabarcoding
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DOI：
10.3389/fmicb.2019.00653
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发表时间：
2019-04-09
影响因子：
5.2
通讯作者：
Bouchez, Agnes
中科院分区：
文献类型：
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作者：
Chonova, Teofana;Kurmayer, Rainer;Bouchez, Agnes
淡水生态系统不断受到人为压力的影响。污水处理厂的污水是污染的主要来源之一，它含有大量的微污染物和宏污染物。经处理的废水的化学成分、毒性水平和对接受国水生生态系统的影响可能因废水来源的不同而有很大差异。与城市te相比，医院te可能含有更多的活性药物物质。底栖硅藻种类和生态多样性高，对人类压力反应快，是重要的生态指标。它们通常用于水质监测。然而，在处理过的废水中，硅藻群落的发展和行为与主要的微和宏观污染物有关，目前还存在知识差距。在本研究中，我们旨在(1)调查硅藻群落对城市和医院te的响应，(2)评估te对接收河流社区的影响。采用DNA元条形码结合高通量测序（HTS）技术，将环境生物膜定殖在污水处理厂和污水处理厂上下游的接收河流中，研究底栖硅藻。同时，还记录了营养物、药品和季节条件的浓度。硅藻元条形码显示，不同生境的底栖生物群落在多样性和结构上存在较大差异。TE站点通常由少数具有多厌氧偏好的属主导，属于运动行会，而河流站点则倾向于来自寡营养和寡厌氧群体的多样化群落。季节变化程度较低。为了对硅藻变化的重要参数进行分类，我们进行了冗余分析，结果表明TE站点内的群落与城市污水中β受体阻滞剂和非甾体抗炎药的浓度较高有关，而医院污水中抗生素和正磷酸盐的浓度较高。此外，指示物种分析表明，河流下游社区检测到的27%的otu是城市或医院TE站点的指示物种，而河流上游没有。最后，通过计算生物硅藻指数（BDI）来评价接收河流的生态状况，表明TEs的释放与水质下降有关。因此，利用DNA元条形码对硅藻群落组成进行深入评估是一种很有前途的技术，可以突出高山河流中污染物的干扰作用。
Freshwater ecosystems are continuously affected by anthropogenic pressure. One of the main sources of contamination comes from wastewater treatment plant (WWTP) effluents that contain wide range of micro- and macropollutants. Chemical composition, toxicity levels and impact of treated effluents (TEs) on the recipient aquatic ecosystems may strongly differ depending on the wastewater origin. Compared to urban TEs, hospital ones may contain more active pharmaceutical substances. Benthic diatoms are relevant ecological indicators because of their high species and ecological diversity and rapid response to human pressure. They are routinely used for water quality monitoring. However, there is a knowledge gap on diatom communities' development and behavior in treated wastewater in relation to prevailing micro- and macropollutants. In this study, we aim to (1) investigate the response of diatom communities to urban and hospital TEs, and (2) evaluate TEs effect on communities in the recipient river. Environmental biofilms were colonized in TEs and the recipient river up- and downstream from the WWTP output to study benthic diatoms using DNA metabarcoding combined with high-throughput sequencing (HTS). In parallel, concentrations of nutrients, pharmaceuticals and seasonal conditions were recorded. Diatom metabarcoding showed that benthic communities differed strongly in their diversity and structure depending on the habitat. TE sites were generally dominated by few genera with polysaprobic preferences belonging to the motile guild, while river sites favored diverse communities from oligotrophic and oligosaprobic groups. Seasonal changes were visible to lower extent. To categorize parameters important for diatom changes we performed redundancy analysis which suggested that communities within TE sites were associated to higher concentrations of beta-blockers and non-steroidal anti-inflammatory drugs in urban effluents vs. antibiotics and orthophosphate in hospital effluents. Furthermore, indicator species analysis showed that 27% of OTUs detected in river downstream communities were indicator for urban or hospital TE sites and were absent in the river upstream. Finally, biological diatom index (BDI) calculated to evaluate the ecological status of the recipient river suggested water quality decrease linked to the release of TEs. Thus, in-depth assessment of diatom community composition using DNA metabarcoding is proposed as a promising technique to highlight the disturbing effect of pollutants in Alpine rivers.