INRAE, UR RiverLy, Villeurbanne, France.
Université Clermont Auvergne, CNRS, Laboratoire Microorganismes: Génome et Environnement (LMGE), Clermont-Ferrand, France.
Rev Environ Contam Toxicol. 2021;253:115-153. doi: 10.1007/398_2019_39.
In freshwater environments, microbial assemblages attached to submerged substrates play an essential role in ecosystem processes such as primary production, supported by periphyton, or organic matter decomposition, supported by microbial communities attached to leaf litter or sediments. These microbial assemblages, also called biofilms, are not only involved in nutrients fluxes but also in contaminants dynamics. Biofilms can accumulate metals and organic contaminants transported by the water flow and/or adsorbed onto substrates. Furthermore, due to their high metabolic activity and their role in aquatic food webs, microbial biofilms are also likely to influence contaminant fate in aquatic ecosystems. In this review, we provide (1) a critical overview of the analytical methods currently in use for detecting and quantifying metals and organic micropollutants in microbial biofilms attached to benthic substrata (rocks, sediments, leaf litter); (2) a review of the distribution of those contaminants within aquatic biofilms and the role of these benthic microbial communities in contaminant fate; (3) a set of future challenges concerning the role of biofilms in contaminant accumulation and trophic transfers in the aquatic food web. This literature review highlighted that most knowledge on the interaction between biofilm and contaminants is focused on contaminants dynamics in periphyton while technical limitations are still preventing a thorough estimation of contaminants accumulation in biofilms attached to leaf litter or sediments. In addition, microbial biofilms represent an important food resource in freshwater ecosystems, yet their role in dietary contaminant exposure has been neglected for a long time, and the importance of biofilms in trophic transfer of contaminants is still understudied.
在淡水环境中，附着在水下基质上的微生物群落对于生态系统过程至关重要，如由周丛生物支持的初级生产，或由附着在叶片凋落物或沉积物上的微生物群落支持的有机物质分解。这些微生物群落，也称为生物膜，不仅参与养分通量，还参与污染物动态变化。生物膜可以积累随水流运输的金属和有机污染物，以及吸附在基质上的污染物。此外，由于其高代谢活性以及在水生食物网中的作用，微生物生物膜也可能影响水生生态系统中污染物的归宿。在本综述中，我们提供了以下内容：（1）对当前用于检测和量化附着在底栖基质（岩石、沉积物、叶片凋落物）上的微生物生物膜中金属和有机微污染物的分析方法的批判性综述；（2）对这些污染物在水生生物膜中的分布以及这些底栖微生物群落在污染物归宿中的作用的综述；（3）关于生物膜在污染物积累和水生食物网中营养转移中的作用的一系列未来挑战。本文献综述强调，关于生物膜与污染物相互作用的大多数知识都集中在周丛生物中的污染物动态变化上，而技术限制仍然阻碍了对附着在叶片凋落物或沉积物上的生物膜中污染物积累的全面估计。此外，微生物生物膜是淡水生态系统中重要的食物资源，但它们在饮食污染物暴露中的作用长期以来一直被忽视，生物膜在污染物营养转移中的重要性仍有待研究。
