{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T22:36:47Z","timestamp":1789166207028,"version":"build-2803163510"},"reference-count":46,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2022,12,15]],"date-time":"2022-12-15T00:00:00Z","timestamp":1671062400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Toxics"],"abstract":"<jats:p>This article focuses on a very peculiar habitat, the thin biofilm that covers the surface of rocks, cobbles, sediment grains, leaf litter, and vegetation on a riverbed. Species composition changes over time and depends on environmental conditions and perturbation of water quality. It provides several ecosystem services, contributing to the biogeochemical fluxes and reducing contamination by absorbing the pollutants. Biofilm into the Toce River (Ossola Valley, Piedmont, Italy) was investigated to assess its capacity to accumulate the metals and macroions from the water column. In this preliminary work, we investigated three sample points, in two different seasons. The community composition of biofilm was determined via morphological analysis (diatoms and non-diatoms algal community). We characterize the biofilm, a community of different organisms, from different perspectives. In the biofilm, Hg was analyzed with an automated mercury analyzer, other metals and macroions with inductively coupled plasma mass spectrometry (ICP-MS) (Al, As, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Pb, and Zn), and the carotenoid and chlorophyll composition of the photosynthetic organism with HPLC analysis for the primary producers. The results evidence a seasonal pattern in metals and macroions levels in the biofilm, and a significant difference in the biofilm community and in carotenoid composition, suggesting the utility of using the biofilm as an additional bioindicator to monitor the water quality of the river.<\/jats:p>","DOI":"10.3390\/toxics10120791","type":"journal-article","created":{"date-parts":[[2022,12,16]],"date-time":"2022-12-16T02:54:02Z","timestamp":1671159242000},"page":"791","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Biofilm and Rivers: The Natural Association to Reduce Metals in Waters"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3536-4886","authenticated-orcid":false,"given":"Nicoletta","family":"Guerrieri","sequence":"first","affiliation":[{"name":"National Research Council, Water Research Institute, Largo Tonolli 50, I-28922 Verbania Pallanza, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7142-6939","authenticated-orcid":false,"given":"Laura","family":"Fantozzi","sequence":"additional","affiliation":[{"name":"National Research Council, Water Research Institute, Largo Tonolli 50, I-28922 Verbania Pallanza, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3627-0363","authenticated-orcid":false,"given":"Andrea","family":"Lami","sequence":"additional","affiliation":[{"name":"National Research Council, Water Research Institute, Largo Tonolli 50, I-28922 Verbania Pallanza, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Simona","family":"Musazzi","sequence":"additional","affiliation":[{"name":"National Research Council, Water Research Institute, Largo Tonolli 50, I-28922 Verbania Pallanza, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8214-1442","authenticated-orcid":false,"given":"Martina","family":"Austoni","sequence":"additional","affiliation":[{"name":"National Research Council, Water Research Institute, Largo Tonolli 50, I-28922 Verbania Pallanza, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Arianna","family":"Orr\u00f9","sequence":"additional","affiliation":[{"name":"National Research Council, Water Research Institute, Largo Tonolli 50, I-28922 Verbania Pallanza, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4321-0721","authenticated-orcid":false,"given":"Laura","family":"Marziali","sequence":"additional","affiliation":[{"name":"National Research Council, Water Research Institute, Via del Mulino 19, I-20861 Brugherio, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3632-8799","authenticated-orcid":false,"given":"Gigliola","family":"Borgonovo","sequence":"additional","affiliation":[{"name":"DeFENS Department of Food, Environmental and Nutritional Sciences, Via Celoria 2, I-20133 Milano, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leonardo","family":"Scaglioni","sequence":"additional","affiliation":[{"name":"DeFENS Department of Food, Environmental and Nutritional Sciences, Via Celoria 2, I-20133 Milano, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,12,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"251","DOI":"10.1038\/nrmicro.2016.15","article-title":"The ecology and biogeochemistry of stream biofilms","volume":"14","author":"Battin","year":"2016","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"106006","DOI":"10.1016\/j.ecolind.2019.106006","article-title":"Shifts in biofilms composition induced by flow stagnation, sewage contamination and grazing","volume":"111","author":"Calapez","year":"2020","journal-title":"Ecol. Indic."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"10735","DOI":"10.1021\/acs.est.0c02975","article-title":"Tolerance patterns in stream biofilms link complex chemical pollution to ecological impacts","volume":"54","author":"Tlili","year":"2020","journal-title":"Environ. Sci. Technol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"563","DOI":"10.1038\/nrmicro.2016.94","article-title":"Biofilms: An emergent form of bacterial life","volume":"14","author":"Flemming","year":"2016","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_5","first-page":"245","article-title":"Different Types of Diatom-Derived Extracellular Polymeric Substances Drive Changes in Heterotrophic Bacterial Communities from Intertidal Sediments","volume":"8","author":"McGenity","year":"2017","journal-title":"Front Microbiol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"118233","DOI":"10.1016\/j.watres.2022.118233","article-title":"Natural biofilm as a potential integrative sample for evaluating the contamination and impacts of PFAS on aquatic ecosystems","volume":"215","author":"Zhang","year":"2022","journal-title":"Water Res."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"140","DOI":"10.1016\/j.microc.2018.06.033","article-title":"Investigation of the metal content of sediments around the historically polluted Potomac River basin in Washington D.C., United States by inductively coupled plasma-optical emission spectroscopy (ICP-OES)","volume":"142","author":"Harris","year":"2018","journal-title":"Microchem. J."},{"key":"ref_8","first-page":"309","article-title":"Geospatial visualization and seasonal variation of heavy metals in river sediments","volume":"9","author":"Reymond","year":"2023","journal-title":"Global J. Environ. Sci. Manage."},{"key":"ref_9","first-page":"323","article-title":"Heavy metals concentration in the sediment of the aquatic environment caused by the leachate discharge from a landfill","volume":"9","author":"Sulistyowati","year":"2023","journal-title":"Global J. Environ. Sci. Manage."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"158407","DOI":"10.1016\/j.scitotenv.2022.158407","article-title":"Developing ecological risk assessment of metals released from sediment based on sediment quality guidelines linking with the properties: A case study for Kaohsiung Harbor","volume":"852","author":"Ju","year":"2022","journal-title":"Sci. Total Environ."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"555","DOI":"10.1007\/s10661-010-1478-4","article-title":"A long-term survey of heavy metals and specific organic compounds in biofilms, sediments, and surface water in a heavily affected river in the Czech Republic","volume":"174","author":"Havel","year":"2011","journal-title":"Environ. Monit. Assess."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1016\/j.envpol.2012.10.012","article-title":"Metal concentrations in stream biofilm and sediments and their potential to explain biofilm microbial community structure","volume":"173","author":"Ancion","year":"2013","journal-title":"Environ. Pollut."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"159391","DOI":"10.1016\/j.scitotenv.2022.159391","article-title":"Characterization of benthic biofilms in mangrove sediments and their variation in response to nutrients and contaminants","volume":"857","author":"Yang","year":"2023","journal-title":"Sci. Total Environ."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"809","DOI":"10.1016\/j.scitotenv.2017.03.219","article-title":"Toxicity risk assessment of mercury, DDT and arsenic legacy pollution in sediments: A triad approach under low concentration conditions","volume":"593","author":"Marziali","year":"2017","journal-title":"Sci. Total Environ."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Marziali, L., and Valsecchi, L. (2021). Mercury Bioavailability in Fluvial Sediments Estimated Using Chironomus riparius and Diffusive Gradients in Thin-Films (DGT). Environments, 8.","DOI":"10.3390\/environments8020007"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1007\/s10750-017-3494-7","article-title":"Spatial and temporal trends of target organic and inorganic micropollutants in Lake Maggiore and Lake Lugano (Italian-Swiss water bodies): Contamination in sediments and biota","volume":"824","author":"Guzzella","year":"2018","journal-title":"Hydrobiologia"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Fantozzi, L., Guerrieri, N., Manca, G., Orr\u00f9, A., and Marziali, L. (2021). An Integrated Investigation of Atmospheric Gaseous Elemental Mercury Transport and Dispersion around a Chlor-Alkali Plant in the Ossola Valley (Italian Central Alps). Toxics, 9.","DOI":"10.3390\/toxics9070172"},{"key":"ref_18","unstructured":"(2022, September 06). Regione Piemonte. Piano di tutela delle acque. Aggiornamento 2021; Bilancio idrico regionale delle acque superficiali, allegato 3A. Available online: https:\/\/www.regione.piemonte.it\/web\/temi\/ambiente-territorio\/ambiente\/acqua\/piano-tutela-delle-acque-aggiornamento-2021."},{"key":"ref_19","unstructured":"ICP Waters Programme Center (2022, September 12). ICP Waters Programme Manual 2010. Report No.6074-2010-ICP Waters (Report 105\/2010). Available online: https:\/\/www.icp-waters.no\/publications\/."},{"key":"ref_20","first-page":"155","article-title":"Diatoms","volume":"Volume 3","author":"Smol","year":"2001","journal-title":"Tracking Environmental Change Using Lake Sediments"},{"key":"ref_21","unstructured":"Ettl, H., Gerloff, J., Heynig, H., and Mollenhauer, D. (1986\u20132004). S\u00fc\u00dfwasserflora von Mitteleuropa. Bacillariophyceae, Gustav Fischer Verlag. Volume 2\/1: Naviculaceae, Volume 2\/2: Bacillariaceae, Epithemiaceae, Surirellaceae, Volume 2\/3: Centrales, Fragilariaceae, Eunotiaceae, Volume 2\/4: Achnanthaceae."},{"key":"ref_22","unstructured":"Lange-Bertalot, H. (2001). Diatoms of Europe, Gantner Verlag. Volume 2: Navicula sensu stricto, 10 Genera Separated from Navicula sensu stricto, Frustulia."},{"key":"ref_23","unstructured":"Lange-Bertalot, H. (2000). Diatoms of Europe, Gantner Verlag. Volume 1: The Genus Pinnularia."},{"key":"ref_24","unstructured":"Lange-Bertalot, H. (2002). Diatoms of Europe, Gantner Verlag. Volume 3: Cymbella."},{"key":"ref_25","unstructured":"Lange-Bertalot, H. (2003). Diatoms of Europe, Gantner Verlag. Volume 4: Cymbopleura, Delicata, Navicymbula, Gomphocymbellopsis, Afrocymbella Supplements to cymbelloid taxa."},{"key":"ref_26","unstructured":"Lange-Bertalot, H. (2011). Diatoms of Europe, Gantner Verlag. Volume 6: Eunotia and some related genera."},{"key":"ref_27","unstructured":"Cantonati, M., Kelly, M.G., and Lange-Bertalot, H. (2017). Freshwater Benthic Diatoms of Central Europe: Over 800 Common Species Used in Ecological Assessment, Koeltz Botanical Book."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"561","DOI":"10.1111\/j.1529-8817.2007.00332.x","article-title":"Morphological and ecological variation within the Achnanthidium minutissimum (Bacillariophyceae) species complex","volume":"43","author":"Potapova","year":"2007","journal-title":"J. Phycol."},{"key":"ref_29","unstructured":"Shannon, C.E., and Weaver, W. (1949). The Mathematical Theory of Communication. University of Illinois Press."},{"key":"ref_30","unstructured":"Pielou, E.C. (1975). Ecological Diversity, John Wiley & Sons."},{"key":"ref_31","first-page":"1","article-title":"Metodo per la valutazione dello stato ecologico delle acque correnti: Comunit\u00e0 diatomiche","volume":"9","author":"Mancini","year":"2009","journal-title":"Rapp. Istisan"},{"key":"ref_32","unstructured":"CEMAGREF (1982). Etude des m\u00e9thodes biologiques d\u2019appr\u00e9ciation quantitative de la qualit\u00e9 des eaux, CEMAGREF. Rapport Division Qualit\u00e9 des Eaux Lyon \u2014 Agence de l\u2019Eau Rh\u00f4ne \u2014 M\u00e9diterran\u00e9e \u2014 Corse."},{"key":"ref_33","unstructured":"Rott, E., Pfister, P., van Dam, H., Pipp, E., Pall, K., Binder, N., and Ortler, K. (1999). Indikationslisten f\u00fcr Aufwuchsalgen in \u00d6sterre-ichischen Fliessgew\u00e4ssern, Wasser wirtschaft Kataster. Teil 2: Trophieindikation und aut\u00f6kologische Anmerkungen Bundesministerium f\u00fcr Land und Forstwirtschaf."},{"key":"ref_34","first-page":"1","article-title":"Zur Vervollkommung der quantitative Phytoplankton Methodik","volume":"9","year":"1958","journal-title":"Mitt.\u2014Int. Ver. Theor. Angew. Limnol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1007\/BF00007865","article-title":"The inverted microscope method of estimating algal numbers and the statistical basis of estimations by counting","volume":"11","author":"Lund","year":"1958","journal-title":"Hydrobiologia"},{"key":"ref_36","unstructured":"Hauer, F.R., and Lamberti, G.A. (2007). Biomass and Pigments of Benthic Algae. Methods in Stream Ecology, Accademic Press. [2nd ed.]."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"25","DOI":"10.4081\/jlimnol.2000.s1.15","article-title":"High resolution analysis of fossil pigments, carbon, nitrogen and sulphur in the sediment of eight European Alpine Lakes: The Molar project","volume":"59","author":"Lami","year":"2000","journal-title":"J. Limnol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1016\/j.jplph.2018.04.011","article-title":"A differential tolerance to mild salt stress conditions among six Italian rice genotypes does not rely on Na+ exclusion from shoots","volume":"226","author":"Bertazzini","year":"2018","journal-title":"J. Plant Physiol."},{"key":"ref_39","unstructured":"U.S. EPA (2021, December 01). \u201cMethod 7473 (SW-846): Mercury in Solids and Solutions by Thermal Decomposition, Amalgamation, and Atomic Absorption Spectrophotometry,\u201d Revision 0. Washington, DC, Available online: https:\/\/www.epa.gov\/sites\/production\/files\/2015-07\/documents\/epa-7473.pdf."},{"key":"ref_40","unstructured":"Metzing, D., Hofbauer, N., Ludwig, G., and Matzke-Hajek, G. (2018). Rote Liste und Gesamtartenliste der limnischen Kieselalgen (Bacillariophyta) Deutschlands. Rote Liste gef\u00e4hrdeter Tiere, Pflanzen und Pilze Deutschlands, Band 7: Pflanzen, Landwirtschaftsverlag. Naturschutz und Biologische Vielfalt 70 (7)."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Roy, S., Llewellyn, C.A., Egeland, E.S., and Johnsen, G. (2011). Phytoplankton Pigments: Characterization, Chemotaxonomy and Applications in Oceanography, Cambridge University Press.","DOI":"10.1017\/CBO9780511732263"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"13","DOI":"10.3354\/meps236013","article-title":"Production of extracellular polymeric substances (EPS) by benthic diatoms: Effect of irradiance and temperature","volume":"236","author":"Wolfstein","year":"2002","journal-title":"Mar. Ecol. Prog. Ser."},{"key":"ref_43","first-page":"565","article-title":"Exocellular polysaccharides in microalgae and cyanobacteria: Chemical features, role and enzymes and genes involved in their biosynthesis","volume":"Volume 6","author":"Borowitzka","year":"2016","journal-title":"The Physiology of Microalgae, Developments in Applied Phycology"},{"key":"ref_44","unstructured":"Oliveira, J.M., Radhouani, H., and Reis, R.L. (2021). Cyanobacterial Extracellular Polymeric Substances (EPS). Polysaccharides of Microbial Origin, Springer."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1016\/j.sedgeo.2012.04.011","article-title":"Chromium and nickel as indicators of source-to-sink sediment transfer in a Holocene alluvial and coastal system (Po Plain, Italy)","volume":"280","author":"Amorosi","year":"2012","journal-title":"Sediment. Geol."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"3271","DOI":"10.1002\/jctb.6978","article-title":"Role of biofilms in the degradation of microplastics in aquatic environments","volume":"97","author":"Debroy","year":"2022","journal-title":"J. Chem. Technol. Biotechnol."}],"container-title":["Toxics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2305-6304\/10\/12\/791\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:42:09Z","timestamp":1760146929000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2305-6304\/10\/12\/791"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,12,15]]},"references-count":46,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2022,12]]}},"alternative-id":["toxics10120791"],"URL":"https:\/\/doi.org\/10.3390\/toxics10120791","relation":{},"ISSN":["2305-6304"],"issn-type":[{"value":"2305-6304","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,12,15]]}}}