Ziino Graziella*, Giarratana Filippo, Nalbone Luca, Lacagnina Paolo, Marotta Stefania M., Giuffrida Alessandro, Panebianco Antonio
Università degli Studi di Messina, Dipartimento di Scienze Veterinarie.
Microplastics in food could represent a risk for human health due to their potential of adsorbing chemical pollutants [1]. Plastic debris can easily reach the top of the food chain, since they are gathered in the digestive tract of several seafood [2]. Moreover, molluscs are mostly used as bio-indicators and can be used for the control of the level of sea-contamination [3]. For all these reasons, the EFSA Panel for Contaminants in the Food Chain was asked to deliver a statement on the presence of microplastics and nanoplastics in food, with particular focus on seafood [1]. The aim of the present study was to evaluate and quantify the presence of plastic extraneous particles (PEP) in 2 species of bivalves regularly commercialized. A total of 51 fresh samples (33 mussels, Mytilus galloprovincialis and 18 clams, Tapes decussatus), from different breeding in Mediterranean Sea (FAO 37.2.2 and 37.2.1), were analyzed for the presence of PEP. A total amount of 10 g of pulp and intervalve liquid from each sample was collected for the soft tissue digestion using hydrogen peroxide 30% Vol, and then processed for flotation, with an over-saturated salt solution (NaCl 1-2g/mL). This process allows the separation of the plastic debris from sediment, based on the specific weight [4]. The supernatant was subsequently filtered by filters with pores diameter of 5 µm and then observed under a stereo-microscope. Plastic debris were identified in 82.4% (42) of the total samples, in particular: 100% (33) of mussels and 50% (9) of clams. The total abundance of plastic fragments (n=120) was 0.3±0.3 PEP/g. Plastic fibers represented the 84.2% (n 101) of PEP, while the 15.8% (n=19) was identified as microplastics. Among different species, M. galloprovincialis revealed a level of contamination (0.36±0.30 PEP/g) significant higher (p<0.05) than Tapes decussatus (0.12±0.22 PEP/g). The study confirmed the wide diffusion of plastic debris in bivalves from Mediterranean Sea, with important differences between mussels and clams. The potential unsafe impact on human health, after consumption of contaminated seafood, needs to be further investigated.
[1] EFSA 2016. Presence of microplastics and nanoplastics in food, with particular focus on seafood. EFSA Panel on Contaminants in the Food Chain (CONTAM). EFSA Journal, 14(6), 2016. [2] Van Cauwenberghe, L., and Janssen, C. R. Microplastics in bivalves cultured for human consumption. Environmental Pollution, 193, 65-70, 2014. [3] Gopikrishna, V. G. Ecotoxicology and Monitoring of Toxic Pollutants in the Marine Environment-A Review. International Journal of Marine Science, 6 (9), 1-20, 2016. [4] Li, J., Yang, D., Li, L., Jabeen, K., and Shi, H. Microplastics in commercial bivalves from China. Environmental Pollution, 207, 190-195, 2015.
Pagellus erythrinus: THE COMPLETE MITOCHONDRIAL GENOME
Marina Ceruso (1), Celestina Mascolo (1,2), Elijah Lowe (2), Giuseppe Palma (3), Aniello Anastasio (1,4),Paolo Sordino (2), Tiziana Pepe (1)
(1) University of Naples "Federico II", Department of Veterinary Medicine and Animal Production. (2) Stazione Zoologica Anton Dohrn, Biology and Evolution of Marine Organisms. (3) Assoittica Italia. (4) Centro di Riferimento
Regionale per la Sicurezza Sanitaria del Pescato (C.Ri.S.Sa.P.)
The study of mitochondrial DNA (mtDNA) has become a very common approach in population genetics and evolutionary studies. MtDNA is used as marker to detect fraudulent substitutions in prepared and transformed fish products [1]; the target nucleotide sequences are fragments belonging to the genes cytochrome b, ribosomal 16S and 12S subunits, and cytochrome c oxidase subunit 1 [2]. However, the use of short segments of the mtDNA may give ambiguous results, because fragments are too short to contain sufficient genetic information. The analysis of the complete mitochondrial genome (mitogenome) of fishery products allows to tackle more thoroughly fish species identities. The Sparidae family comprises about 41 species, some of which are of considerable economic importance [3]. However, yet there is a paucity of genetic information regarding these species. The common pandora (Pagellus erythrinus) is one of the most commercially-caught Sparidae species in the Mediterranean Sea and is often fraudulently replaced with less expensive species of the same genus. The aim of this research was to obtain the complete nucleotide sequence of the P. erythrinus mitogenome in order to obtain more information for unambiguous species identification. A whole specimen was obtained from fish market and identified based on morphological and molecular features. Total DNA was extracted from dorsal fin using the DNeasy Blood & Tissue Kit (Qiagen) according to manufacturer’s instructions. The mitogenome of P. erythrinus was determined by using a combination of long and short PCR, followed by Sanger and Illumina MiSeq sequencing methods. The total lenght of the common pandora complete mitogenome was determined to be 16,694 bp. It contains 13 protein-coding genes, 2 ribosomal RNA genes (12S rRNA and 16S rRNA), 22 transfer RNA genes (tRNA) and 1 control region. Most of the genes were encoded on the heavy strand, with only the NADH dehydrogenase subunit 6 (ND6) and eight tRNA genes [Gln, Ala, Asn, Cys, Tyr, Ser (UCN), Glu, Pro] encoded on the light strand. The nucleotide composition is 27.4% A, 28.2% C, 27.5% T and 16.9% G, which is similar to other Sparidae mitogenomes [4]. All the protein-coding genes began with an ATG start codon, except for COX1 and NAD4, which started with GTG. Five types of stop codons revealed are TAA (ND1, ND2, ATP8, ATP6, COX3, ND4L, ND6), AGG (COX1), and T (COX2, ND3, ND4, CYTB). The 12S and 16S rRNA genes were located between the tRNA-Phe (GAA) and tRNA-Leu (TAA) genes, and were separated by the tRNA-Val gene. The 22 tRNA genes vary from 66 to 74 bp in length. The 994 bp-long control region was located between tRNA-Pro (TGG) and tRNA-Phe (GAA). In agreement with Regulation (EU) 1379/2013, the complete mitogenome characterization will allow a complete comparison and analysis of fish species. Other Sparidae mitogenomes are currently under sequencing for comparison studies.
[1] Pepe et al. Fish species identification in surimi-based products, J Agric Food Chem,55:3681-5, 2007. [2] Chin et al. Detection of mislabelled seafood products in Malaysia by DNA barcoding: improving transparency in food market, Food Control, 64:247-56, 2016. [3] D.M. MIPAAF, 31 Gennaio 2008. [4] Dray et al. The complete mitochondrial genome of the gilthead seabream Sparus aurata L. (Sparidae), Mitochondrial DNA A DNA Mapp Seq Anal, 27:781-2, 2016.