Department of Environmental Sciences, Institute of Aquatic Ecology, Faculty of Sciences, University of Girona (UdG), Campus Montilivi, 17071 Girona, Spain.
Department of Environmental Sciences, Institute of Aquatic Ecology, Faculty of Sciences, University of Girona (UdG), Campus Montilivi, 17071 Girona, Spain.
Ecotoxicol Environ Saf. 2014 May;103:82-90. doi: 10.1016/j.ecoenv.2013.11.007. Epub 2013 Dec 28.
This study aimed to explore the use of antioxidant enzyme activities (AEA) and biofilm metal accumulation capacity in natural communities as effect-based indicator of metal exposure in fluvial systems. To achieve these objectives, an active biomonitoring using fluvial biofilm communities was performed during 5 weeks. Biofilm was colonized over artificial substrata in a non-polluted site. After 5 weeks, biofilms were translocated to four different sites with different metal pollution in the same stream. The evolution of environmental parameters as well as biofilm responses was analysed over time. Physicochemical parameters were different between sampling times as well as between the most polluted site and the less polluted ones, mainly due to Zn pollution. In contrast, AEA and metal accumulation in biofilms allowed us to discriminate the high and moderate metal pollution sites from the rest. Zn, the metal with the highest contribution to potential toxicity, presented a fast and high accumulation capacity in biofilms. According to the multivariate analysis, AEA showed different responses. While catalase (CAT) and ascorbate peroxidase (APX) variability was mainly attributed to environmental stress (pH, temperature and phosphate concentration), glutathione-S-transferase (GST) changes were related to metal pollution. Glutathione reductase (GR) and superoxide dismutase (SOD) responses were related to both stress factors. AEA and metal accumulation are proposed as sensitive effect-based field methods, to evaluate biofilm responses after acute metal exposure (e.g. an accidental spill) due to their capacity to respond after few hours, but also in routinely monitoring due to their persistent changes after few weeks of exposure. These tools could improve the Common Implementation Strategy (CIS) of the Water Framework Directive (WFD) as expert group request.
本研究旨在探索抗氧化酶活性（AEA）和生物膜金属积累能力在自然群落中的应用，作为河流系统中金属暴露的基于效应的指标。为了实现这些目标，在 5 周的时间内使用河流生物膜群落进行了主动生物监测。生物膜在无污染地点的人工基质上定植。5 周后，生物膜被转移到同一溪流中具有不同金属污染的四个不同地点。随着时间的推移，分析了环境参数和生物膜反应的演变。物理化学参数在采样时间之间以及在污染最严重的地点和污染较轻的地点之间有所不同，主要是由于 Zn 污染。相比之下，AEA 和生物膜中的金属积累使我们能够将高污染和中度污染的地点与其他地点区分开来。Zn 是对潜在毒性贡献最大的金属，在生物膜中具有快速和高的积累能力。根据多元分析，AEA 表现出不同的反应。虽然过氧化氢酶 (CAT) 和抗坏血酸过氧化物酶 (APX) 的变异性主要归因于环境压力（pH 值、温度和磷酸盐浓度），但谷胱甘肽-S-转移酶 (GST) 的变化与金属污染有关。谷胱甘肽还原酶 (GR) 和超氧化物歧化酶 (SOD) 的反应与这两个应激因素都有关。AEA 和金属积累被提议作为敏感的基于效应的现场方法，以评估急性金属暴露（例如意外泄漏）后生物膜的反应，因为它们能够在几小时后做出反应，而且在数周的暴露后，它们也能持续变化。这些工具可以根据专家组的要求，改进《水框架指令》（WFD）的共同实施战略（CIS）。
