Irstea Antony - Unité de Recherche Hydrosystèmes et Bioprocédés (HBAN), 1 rue Pierre-Gilles de Gennes, CS 10030, F-92761 Antony Cedex, France; AgroParisTech, F-75005 Paris, France; FIRE, FR-3020, 4 Place Jussieu, 75005 Paris, France.
Irstea Antony - Unité de Recherche Hydrosystèmes et Bioprocédés (HBAN), 1 rue Pierre-Gilles de Gennes, CS 10030, F-92761 Antony Cedex, France; FIRE, FR-3020, 4 Place Jussieu, 75005 Paris, France.
Water Res. 2014 Mar 15;51:152-62. doi: 10.1016/j.watres.2013.12.002. Epub 2013 Dec 22.
It is difficult to assess the biological consequences of diffuse water contamination by micropollutants which are present in rivers at low, even sublethal levels. River biofilms, which respond quickly to changes of environmental parameters, are good candidates to acquire knowledge on the response of aquatic organisms to diffuse chemical contamination in the field. The study was designed as an attempt to link biofilm metal tolerance and metallic contamination in a field survey covering 13 different sampling sites in the Seine river basin (north of France) with low contamination levels. Cd and Zn tolerance of heterotrophic communities was assessed using a short-term toxicity test based on β-glucosidase activity. Metal tolerance levels varied between sites but there was no obvious correlation between tolerance and corresponding water contamination levels for Cd and Zn. Indeed, metallic contamination at the sampling sites remained subtle when compared to water quality standards (only two sampling sites had either Zn or both Cu and Zn concentrations exceeding the Environmental Quality Standards set by the EU Water Framework Directive). Yet, multivariate analysis of the data using Partial Least Squares Regression revealed that both metallic and environmental parameters were important variables explaining the variability of metal tolerance levels. Automated Ribosomal Intergenic Spacer Analysis (ARISA) was also performed on both bacterial and eukaryotic biofilm communities from the 13 sampling sites. Multivariate analysis of ARISA fingerprints revealed that biofilms with similar tolerance levels have similar ARISA profiles. Those results confirm that river biofilms are potential indicators of low, diffuse contamination levels of aquatic systems.
评估在河流中以低浓度甚至亚致死水平存在的微量污染物造成的弥散性水污染的生物学后果是困难的。河流生物膜对环境参数的变化反应迅速，是了解水生生物对野外弥散化学污染的反应的良好候选物。本研究旨在尝试将生物膜的金属耐受性与金属污染联系起来，该研究在法国北部塞纳河流域的 13 个不同采样点进行了现场调查，这些采样点的污染水平较低。使用基于β-葡萄糖苷酶活性的短期毒性试验评估了异养群落对 Cd 和 Zn 的耐受性。金属耐受水平在各采样点之间有所差异，但 Cd 和 Zn 的耐受水平与相应的水污染物水平之间没有明显的相关性。实际上，与水质标准相比，采样点的金属污染仍然很轻微（只有两个采样点的 Zn 或 Cu 和 Zn 的浓度超过了欧盟水框架指令规定的环境质量标准）。然而，使用偏最小二乘回归的多元数据分析表明，金属和环境参数都是解释金属耐受水平变化的重要变量。还对来自 13 个采样点的细菌和真核生物膜群落进行了自动核糖体基因间隔区分析（ARISA）。ARISA 指纹图谱的多元分析表明，具有相似耐受水平的生物膜具有相似的 ARISA 图谱。这些结果证实，河流生物膜是水生系统低水平弥散污染的潜在指标。
