Articolo in rivista, 2020, ENG, 10.1016/j.scitotenv.2020.138457

Interplay between extracellular polymeric substances (EPS) from a marine diatom and model nanoplastic through eco-corona formation

Grassi Giacomo; Gabellieri Edi; Cioni Patrizia; Paccagnini Eugenio; Faleri Claudia; Lupetti Pietro; Corsi Ilaria and Morelli Elisabetta

Grassi, G (Corresponding Author), Univ Siena, Dept Phys Earth & Environm Sci, 4 Via Mattioli, I-53100 Siena, Italy. Grassi, Giacomo; Corsi, Ilaria, Univ Siena, Dept Phys Earth & Environm Sci, 4 Via Mattioli, I-53100 Siena, Italy. Gabellieri, Edi; Cioni, Patrizia; Morelli, Elisabetta, CNR, Inst Biophys, Via Moruzzi 1, I-56124 Pisa, Italy. Paccagnini, Eugenio; Faleri, Claudia; Lupetti, Pietro, Univ Siena, Dept Life Sci, 4 Via Mattioli, I-53100 Siena, Italy. Paccagnini, Eugenio; Faleri, Claudia; Lupetti, Pietro, 2 Via Aldo Moro, I-53100 Siena, Italy.

The occurrence of nanoplastics in oceans' surface waters is no more a hypothesis and it could severely affect marine organisms from different trophic levels. Nanoscale particles interaction with dissolved natural organic matter (NOM) significantly influence their behaviour and consequently bioavailability and toxicity to marine species. Extracellular polymeric substances (EPS) are among the main components of the NOM pool in seawater yet have been so far little investigated for their effect in altering the physical-chemical properties of nanosized objects. Here we employed EPS from marine diatom Phaeodactylum tricornutum to study the evolution of an eco-corona formation upon incubation with 60 nm carboxylated polystyrene nanoparticles (PS-COOH NPs), as proxy for nanoplastics in seawater. EPS significantly reduced PS-COOH NPs aggregation rate compared to biomolecule free natural seawater (NSW) and caused the formation of complexes constituted by both carbohydrate and protein components. Size Exclusion Chromatography (SEC) revealed four main distinct groups of peaks, spanning from high (>100 kDa) to low molecular weight (20 kDa) molecules, characterized by a high chemical heterogeneity. The lowering of the chromatographic signals detected after EPS incubation with PS-COOH NPs, mainly in the eluates at high molecular weight, suggests that an important fraction of EPS remained adsorbed on PS-COOH NPs. In agreement, SDS-PAGE analysis of proteins adsorbed on PS-COOH showed the occurrence of an eco-corona formed by proteins in the range of molecular weight 30-100 kDa. No toxicity to diatoms was observed upon PS-COOH exposure (72 h, 1-100mg L-1) even by adding a further source of exogenous EPS during exposure. Moreover, the addition of EPS reduced ROS production, even when cells were incubated with PS-COOH NPs at 10 and 50 mg L-1, suggesting an antioxidant scavenging activity of EPS. (C) 2020 Elsevier B.V. All rights reserved.

Science of the total environment 725

Keywords

Extracellular polymeric substances, Phaeodactylum tricornutum, Nanoplastic, Eco-corona, Toxicity, Marine environment, NATURAL ORGANIC-MATTER, METAL-OXIDE NANOPARTICLES, EXOPOLYMER PARTICLES TEP, AGGREGATION KINETICS, PHAEODACTYLUM-TRICORNUTUM, COLLOIDAL STABILITY, GOLD NANOPARTICLES, OXIDATIVE STRESS, FRESH-WATER, POLYSTYRENE NANOPARTICLES

CNR authors

Gabellieri Edi, Cioni Patrizia, Morelli Elisabetta

CNR institutes

IBF – Istituto di biofisica

ID: 434388

Year: 2020

Type: Articolo in rivista

Creation: 2020-10-21 08:52:48.000

Last update: 2022-11-16 10:18:11.000

External links

OAI-PMH: Dublin Core

OAI-PMH: Mods

OAI-PMH: RDF

DOI: 10.1016/j.scitotenv.2020.138457

External IDs

CNR OAI-PMH: oai:it.cnr:prodotti:434388

DOI: 10.1016/j.scitotenv.2020.138457

ISI Web of Science (WOS): 000537428300008