Effects of polypropylene nanofibers on soft corals.

Current information regarding the effects of both micro- and nano-plastic debris on coral reefs is limited; especially the toxicity onto corals from nano-plastics originating from secondary sources such as fibers from synthetic fabrics. Within this study, we exposed the alcyonacean coral Pinnigorgia flava to different concentrations of polypropylene secondary nanofibers (0.001, 0.1, 1.0 and 10 mg/L) and then assayed mortality, mucus production, polyps retraction, coral tissue bleaching, and swelling. The assay materials were obtained by artificially weathering non-woven fabrics retrieved from commercially available personal protective equipment. Specifically, polypropylene (PP) nanofibers displaying a hydrodynamic size of 114.7 ± 8.1 nm and a polydispersity index (PDI) of 0.431 were obtained after 180 h exposition in a UV light aging chamber (340 nm at 0.76 Wˑm-2ˑnm-1). After 72 h of PP exposure no mortality was observed but there were evident stress responses from the corals tested. Specifically, the application of nanofibers at different concentrations caused significant differences in mucus production, polyps retraction and coral tissue swelling (ANOVA, p < 0.001, p = 0.015 and p = 0.015, respectively). NOEC (No Observed Effect Concentration) and LOEC (Lowest Observed Effect concentration) at 72 h resulted 0.1 mg/L and 1 mg/L, respectively. Overall, the study indicates that PP secondary nanofibers can cause adverse effects on corals and could potentially act as a stress factor in coral reefs. The generality of the method of producing and assaying the toxicity of secondary nanofibers from synthetic textiles is also discussed.

Detection of microplastics and phthalic acid esters in sea urchins from Sardinia (Western Mediterranean Sea).

The occurrence of microplastics (MPs) and phthalic acid esters (PAEs) in wild purple sea urchins (Paracentrotus lividus) of Sardinia (Italy, Western Mediterranean Sea) was surveyed. Specifically, MPs were analyzed in the digestive tract by µFTIR and PAEs in the gonads by SPME-LC-MS/MS. 9 out of 22 specimens resulted contaminated with MPs and 20 displayed levels of PAEs over the quantification limit. A total of 23 MPs were detected with a maximum concentration of 4 microplastics/individual in the commercially undersized specimens. PAEs displayed average concentration of 32 ng/g, σ = 5.3 with maximum value of 77 ng/g. The most abundant congeners were DEHP (17 ng/g, σ = 4.3) and DBP (10 ng/g, σ = 2.5). Statistical analysis showed correlation between DEHP and fiber concentrations and among the concentration of MEP, DEP, DBP and BBzP. Due to local use of sea urchin gonads as gourmet delicacy, the potential human exposition to MPs and PAEs by consumption is also discussed.

Two-dimensional gel and shotgun proteomics approaches to distinguish fresh and frozen-thawed curled octopus (Eledone cirrhosa).

The substitution and sale of frozen-thawed fish labeled as fresh is a widespread, difficult to unmask commercial fraud and a potential risk for consumer health. Proteomics could help to identify markers for the rapid screening of food samples and the identification of frozen-thawed seafood. Using two-dimensional electrophoresis (2-DE) and high-resolution liquid chromatography tandem mass spectrometry (LC-MS/MS), we identified biomarkers that are able to discriminate between fresh and frozen-thawed tissue samples of curled octopus (Eledone cirrhosa). The 2-DE analysis showed a significant reduction in two protein spots (molecular weight of 45-50 kDa, isoelectric point of 6.5-7) identified as transgelin. At shotgun analysis, nine proteins resulted modulated and transgelin was confirmed as down-regulated, making it a potentially useful marker for differentiating between fresh and frozen-thawed fish product samples. BIOLOGICAL SIGNIFICANCE: This work, based on two different proteomics approaches, investigated differentially expressed proteins in the tentacles of the curled octopus (E. cirrhosa) after freezing-thawing processes. We were able to characterize the proteome of the tentacles, increasing our knowledge on this species, and a common down-regulated protein was identified by 2-DE and shotgun analysis, a calponin-like protein called transgelin, suggesting a potential use as a marker to distinguish different states of conservation in this species.