Fate and effects of graphene oxide alone and with sorbed benzo(a)pyrene in mussels Mytilus galloprovincialis

Graphene oxide (GO) has gained a great scientific and economic interest due to its unique properties. As incorporation of GO in consumer products is rising, it is expected that GO will end up in oceans. Due to its high surface to volume ratio, GO can adsorb persistent organic pollutants (POPs), such as benzo(a)pyrene (BaP), and act as carrier of POPs, increasing their bioavailability to marine organisms. Thus, uptake and effects of GO in marine biota represent a major concern. This work aimed to assess the potential hazards of GO, alone or with sorbed BaP (GO+BaP), and BaP alone in marine mussels after 7 days of exposure. GO was detected through Raman spectroscopy in the lumen of the digestive tract and in feces of mussels exposed to GO and GO+BaP while BaP was bioaccumulated in mussels exposed to GO+BaP, but especially in those exposed to BaP. Overall, GO acted as a carrier of BaP to mussels but GO appeared to protect mussels towards BaP accumulation. Some effects observed in mussels exposed to GO+BaP were due to BaP carried onto GO nanoplatelets. Enhanced toxicity of GO+BaP with respect to GO and/or BaP or to controls were identified for other biological responses, demonstrating the complexity of interactions between GO and BaP.This work was funded by the Spanish MINECO (NACE project CTM2016–81130-R) and the Basque Government (grants to consolidated research group IT1302–19 and IT1743–22, and predoctoral fellowship to NGS)

Effects of microplastics alone or with sorbed oil compounds from the water accommodated fraction of a North Sea crude oil on marine mussels (Mytilus galloprovincialis)

Microplastics (MPs) can adsorb persistent organic pollutants such as oil hydrocarbons and may facilitate their transfer to organisms (Trojan horse effect). The aim of this study was to examine the effects of a 21 day dietary exposure to polystyrene MPs of 4.5 mu m at 1000 particles/mL, alone and with sorbed oil compounds from the water accommodated fraction (WAF) of a naphthenic North Sea crude oil at two dilutions (25 % and 100 %), on marine mussels. An addi-tional group of mussels was exposed to 25 % WAF for comparison. PAHs were accumulated in mussels exposed to WAF but not in those exposed to MPs with sorbed oil compounds from WAF (MPs-WAF), partly due to the low concen-tration of PAHs in the studied crude oil. Exposure to MPs or to WAF alone altered the activity of enzymes involved in aerobic (isocitrate dehydrogenase) and biotransformation metabolism (glutathione S-transferase). Prevalence of oo-cyte atresia and volume density of basophilic cells were higher and absorption efficiency lower in mussels exposed to MPs and to WAF than in controls. After 21 days MPs caused DNA damage (Comet assay) in mussel hemocytes. In conclusion, a Trojan horse effect was not observed but both MPs and oil WAF caused an array of deleterious effects on marine mussels at different levels of biological organization.This work was funded by Spanish MINECO (NACE project CTM2016-81130-R), Basque Government (consolidated group IT1302-19 and IT1743-22 and predoctoral fellowship to NGS) and UPV/EHU (VRI grant PLASTOX). Work carried out within the EU project PLASTOX (JPI Oceans 005/2015) and the EU H2020-BG-2005-2 project GRACE (grant agreement number 679266)

Cell and tissue level responses in mussels Mytilus galloprovincialis dietarily exposed to PVP/PEI coated Ag nanoparticles at two seasons

Silver nanoparticles (Ag NPs) are present in numerous consumer products due to their antimicrobial and other unique properties, thus concerns about their potential input into aquatic ecosystems are increasing. Toxicity of Ag NPs in waterborne exposed aquatic organisms has been widely investigated, but studies assessing the potential toxic effects caused after ingestion through the food web, especially at low realistic concentrations, remain scarce. Moreover, it is not well known whether season may influence toxic effects of Ag NPs. The main objective of this study was to determine cell and tissue level responses in mussels Mytilus galloprovincialis dietarily exposed to poly-N-vinyl-2-pirrolidone/polyethyleneimine (PVP/PEI) coated 5 nm Ag NPs for 1, 7 and 21 days both in autumn and spring. Mussels were fed every day with microalgae Isochrysis galbana exposed for 24 h to a low dose (1 mu g Ag/L Ag NPs) in spring and to a higher dose (10 mu g Ag/L Ag NPs) in spring and autumn. Mussels fed with microalgae exposed to the high dose accumulated Ag significantly after 21 days in both seasons, higher levels being measured in autumn compared to spring. Intralysosomal metal accumulation measured in mussel digestive gland and time- and dose-dependent reduction of mussels health status was similar in both seasons. DNA strand breaks increased significantly in hemocytes at both exposure doses along the 21 days in spring and micronuclei frequency showed an increasing trend after 1 and 7 days of exposure to 1 mu g Ag/L Ag NPs in spring and to 10 mu g Ag/L in both seasons. Values decreased after 21 days of exposure in all the cases. In conclusion, PVP/PEI coated 5 nm Ag NPs ingested through the food web were significantly accumulated in mussel tissues and caused adverse cell and tissue level effects both in autumn and in spring.This work has been funded by the Spanish Ministry of Economy and Competitiveness (Nano Silver Omics project MAT2012-39372), Basque Government (SAIOTEK project S-PE13UN142 and Consolidated Research Group GIC IT810-13 and IT1302-19), the University of the Basque Country UPV/EHU (UFI 11/37 and PhD fellowship to N.D.) and French Ministry of Higher Education and Research (PhD fellowship to M.M.)

Ehunen biologia

184 p.Lan honek hauxe du xede: Biozientziak (Biologia, Biokimika eta Biologia Molekularra, Bioteknologia eta Medikuntza) ikasten ari diren ikasleei Ehunen Biologia arloan testuliburu egoki eta erabilgarri bat eskaintzea. Histologia alorrean, liburu eta atlas histologiko ugari daude argitaratuta, baina ikasleei beren apunteak osatzeko euskarazko ikasmateriala sortzea izan da gure asmoa. Liburu honetan, animalien eta landareen ehun nagusiak deskribatzen dira. Testuan zehar emandako informazioa ulergarriagoa izan dadin, ikonografia eta mikroargazki lagungarriak aukeratu dira. Amaieran, gai bakoitzean agertzen diren termino nagusiak definitzen dituen glosarioa gehitu da. Azkenengo atalean, bibliografia zerrendatu da, eta Ehunen Biologian informazio-iturri moduan erabili daitezkeen testuliburu, artikulu eta web orriak ageri dira. Lan hau lau atal nagusitan dago banatuta: Garapenaren Zelulen Biologia, Animalia Histologia, Landare Histologia eta Metodoak eta Teknikak Histologian. Ehunen jatorri enbrionarioa deskribatzen duen hasierako atal horretan, animaliengan enbriogenesian zehar gertatzen diren desberdintzapen-prozesu goiztiarrak azaltzen dira. Ondoren, ornodunetan aurkitu daitezkeen lau ehun nagusiak lantzen dira, hau da, epitelioa, ehun konektiboa, muskulua eta nerbioa. Ehun bakoitzaren ezaugarri nagusiak eta osagaiak deskribatzen dira. Gainera, honako hauek modu zehatzean aurkezten dira: zelula motak, antolaketa mailak, garapena eta desberdintzapena, berreraketa, funtzioak eta beste ehunekiko duten erlazioa zein organoen eraketan nola hartzen duten parte. Ornodunen ehunez gain, ornogabeetan agertzen diren ehun berezi nagusiak deskribatzen dira. Landareen histologiari dagokion atalean, egitura nagusiak eta zelula-motak azaltzen dira. Azkenik, egitura histologikoen azterketarako erabiltzen diren metodo eta prozesamendu arruntenak deskribatzen dira

Ehunen biologia

184 p.Lan honek hauxe du xede: Biozientziak (Biologia, Biokimika eta Biologia Molekularra, Bioteknologia eta Medikuntza) ikasten ari diren ikasleei Ehunen Biologia arloan testuliburu egoki eta erabilgarri bat eskaintzea. Histologia alorrean, liburu eta atlas histologiko ugari daude argitaratuta, baina ikasleei beren apunteak osatzeko euskarazko ikasmateriala sortzea izan da gure asmoa. Liburu honetan, animalien eta landareen ehun nagusiak deskribatzen dira. Testuan zehar emandako informazioa ulergarriagoa izan dadin, ikonografia eta mikroargazki lagungarriak aukeratu dira. Amaieran, gai bakoitzean agertzen diren termino nagusiak definitzen dituen glosarioa gehitu da. Azkenengo atalean, bibliografia zerrendatu da, eta Ehunen Biologian informazio-iturri moduan erabili daitezkeen testuliburu, artikulu eta web orriak ageri dira. Lan hau lau atal nagusitan dago banatuta: Garapenaren Zelulen Biologia, Animalia Histologia, Landare Histologia eta Metodoak eta Teknikak Histologian. Ehunen jatorri enbrionarioa deskribatzen duen hasierako atal horretan, animaliengan enbriogenesian zehar gertatzen diren desberdintzapen-prozesu goiztiarrak azaltzen dira. Ondoren, ornodunetan aurkitu daitezkeen lau ehun nagusiak lantzen dira, hau da, epitelioa, ehun konektiboa, muskulua eta nerbioa. Ehun bakoitzaren ezaugarri nagusiak eta osagaiak deskribatzen dira. Gainera, honako hauek modu zehatzean aurkezten dira: zelula motak, antolaketa mailak, garapena eta desberdintzapena, berreraketa, funtzioak eta beste ehunekiko duten erlazioa zein organoen eraketan nola hartzen duten parte. Ornodunen ehunez gain, ornogabeetan agertzen diren ehun berezi nagusiak deskribatzen dira. Landareen histologiari dagokion atalean, egitura nagusiak eta zelula-motak azaltzen dira. Azkenik, egitura histologikoen azterketarako erabiltzen diren metodo eta prozesamendu arruntenak deskribatzen dira

Impacts of dietary exposure to different sized polystyrene microplastics alone and with sorbed benzo[a]pyrene on biomarkers and whole organism responses in mussels Mytilus galloprovincialis

Due to their hydrophobicity and relatively large surface area, microplastics (MPs) can act as carriers of hydrophobic pollutants in the ocean and may facilitate their transfer to organisms. This study examined effects of dietary exposure to polystyrene MPs of 0.5 and 45 mu m alone and with sorbed benzo[a]pyrene (BaP) on mussels Mytilus galloprovincialis in order to elucidate the effects of MP size and the presence of sorbed BaP on the organism. MPs were provided daily, mixed with algae, during 26 days at equivalent mass (0.058 mg/L), corresponding to 1000 particles/mL for 4.5 mu m MPs and to 7.44 x 10(5) particles/mL for 0.5 mu m MPs. Effects were determined on early cellular biomarkers in hemocytes, structure and cell type composition of digestive tubules (DTs), histopathology and whole organism responses (condition index (CI), clearance rate (CR), food absorption efficiency (AE), respiration rate (RR) and scope for growth (SFG)). BaP concentrations in mussels increased with time, in particular when sorbed to smaller MPs. Large MPs were abundant in the lumen of stomach and DTs, but were also occasionally found within epithelial cells. Effects in all treatments increased with exposure time. MPs with sorbed BaP were more toxic than MPs alone according to hemocyte viability and catalase activity and to the quantitative structure of DT epithelium. Higher toxicity of small MPs compared to larger ones was recorded for DNA damage and cell composition of DTs. At tissue level a slight increase in prevalence of inflammatory responses occurred in all exposed groups. At whole organism level a compensatory effect was observed on absorption efficiency across MP treatments at day 26, resulting in increased SFG in mussels exposed to small MPs with sorbed BaP. This could be related to an increased energy need to deal with stress observed in biomarkers. Further work is required to understand the Trojan horse effect of a variety of plastic type, size, shape combinations together with a wide variety of pollutants. (C) 2019 The Authors. Published by Elsevier B.V.This work was funded by Spanish MINECO (NACE project CTM2016-81130-R), Basque Government (consolidated group IT810-13) and predoctoral fellowship to NGS and UPV/EHU (UFI 11/37, VRI grant PLASTOX). Work carried out within EU project PLASTOX (JPI Oceans 005/2015)