Effects of combined exposures of fluoranthene and polyethylene or polyhydroxybutyrate microplastics on oxidative stress biomarkers in the blue mussel (Mytilus edulis)

Abstract

A growing interest in developing and commercialization of new ecofriendly plastic polymers is 26 occurring attributed to the impact of marine plastics debris and microplastics that result from the 27 degradation of oil-based polymers as these substances adversely affect ecosystem health. Recently, polyhydroxybutyrate (PHB) has become of interest due its biodegradability and physicochemical 29 properties. However, biological consequences resulting from bioplastics exposure remains to be 30 determined. Further, few data are apparently available regarding the potential for bioplastics to act as a 31 vector for exogenous chemicals in the environment. The aim of the study was to compare the effects of 32 polyethylene (PE MPs) and polyhydroxybutyrate (PHB MPs) microplastics administered alone or in 33 combination with fluoranthene (Flu) on detoxifying enzymes in digestive glands and gills of Mytilus 34 edulis. Blue mussels were exposed for 96hr to 8 experimental groups: control, Flu-only, PE MPs-only, 35 PHB MPs-only, PE MPs-Flu co-exposure, PHB MPs-Flu co-exposure, Flu-incubated PE MPs and Flu-36 incubated PHB MPs. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx), 37 glutathione S-transferase (GST) and glutathione reductase (GR) were found to be significantly 38 susceptible to Flu and plastics in both tissues. Interestingly, single exposure to PHB MPs led to 39 decreased levels of CAT and GST in gills, SOD in digestive glands and SeGPx in both tissues. In co-40 exposure and incubation treatments, biochemical responses were generally comparable with those 41 exerted by PE MPs or PHB MPs only, suggesting an apparent absence of combined effects with 42 pollutant. Data demonstrate the ecotoxicological impact of bioplastics materials on digestive glands 43 and gills of Mytilus edulis.

Characterization and Biotechnological Potential of Intracellular Polyhydroxybutyrate by Stigeoclonium sp. B23 Using Cassava Peel as Carbon Source

“…In contrast to the observed toxicity on zebrafish embryos, PHB is described as a non-toxic biopolymer [ 57 ], and PHB films such as poly(3-hydroxyoctanoate) (PHO) were not toxic on L929 cells and not pro-inflammatory [ 58 ]. However, PHB biopolymers decreased oxidative stress markers in the blue mussel [ 59 ].…”

Effects of pollution on marine organisms

“…As the phosphorylation that is involved in the inhibition of CbE stoichiometrically destroys the pesticide molecule, it was thought that CbE could play a protective role for other enzymes like AChE. Magara et al (2019) assessed the toxicity of polyethylene beads (PE) and the biodegradable biopolymer polyhydroxybutyrate (PHB), both alone and in combination with fluoranthene (Flu), either adsorbed onto the microplastic (MP) or coadminstered with the plastic, to mussels (M. edulis). A 96-hr exposure to 100 μg/L Flu and/or 1,000 MP/L (nominal) caused a reduction in gill CAT, Se-GPx, and GST activity in most treatments.…”

First insights into oxidative stress and theoretical environmental risk of Bronopol and Detarox® AP, two biocides claimed to be ecofriendly for a sustainable aquaculture

“…Characterizing the toxicity for non-target organisms and the potential risk of Bronopol and Detarox® AP in aquatic environments is of pivotal importance to preserve the ecological balance of aquatic ecosystems. Oxidative stress biomarkers, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione S-transferase (GST) enzymes constitute a key defense pathway against the oxidative pressure driven by reactive oxygen species (ROS) in aquatic models (Semedo et al, 2012;Magara et al, 2019;Cui et al, 2020;Dörr et al, 2020;Elia et al, 2019Elia et al, , 2020Pastorino et al, 2020;Stara et al, 2020). Moreover, the potential risk in aquatic environments is a crucial factor in determining the eco-sustainability of any substance, especially when information on their presence in the environment is lack, as for Bronopol and Detarox® AP.…”