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News Article | December 27, 2016
Site: phys.org

Consumption of seafood is regarded as healthy since it contains high quality proteins, vitamins and omega-3 polyunsaturated fatty acids. But it might also put us at risk of exposure to environmental pollutants. How much do we know about our eating choices? One answer could come from a personal fish calculator designed by European researchers, to understand how much of our diet is healthy. It is very simple; you must select your age range, the amount and species consumed per week. Have you eaten spaghetti with clams and fried sardines? The device will quickly calculate your exposure to methylmercury and other pollutants. The calculator is the brainchild of the ECSafeSEAFOOD project, which has analysed the prevalence of marine toxins, microplastics and other chemical contaminants of growing concern, found in seafood sold in supermarkets across Europe. Contaminants of emerging concern are substances for which no maximum levels have been laid down in EU legislation nor require revision. "Sensitive, rapid and cost-effective screening methods were validated in a large set of seafood samples. Overall, the levels of contaminants in seafood were low, there are no risks for consumers. The only pollutants that may represent a concern for those who consume a lot of seafood were methylmercury and PBDE99 (industrial contaminants)", says António Marques from the Portuguese Marine and Atmospheric Institute (IPMA) in Lisbon, Portugal. "The exposure to these contaminants through seafood needs to be more finely assessed. Such information is crucial for the European food safety authorities to adjust the legislation", he adds. For example, no limits have been established for methylmercury in food. In the Po estuary in Italy, which is one of the top sites for mollusc farming in Europe, the scientists also found the highest level of pharmaceuticals such as the psychiatric drugs venlafaxine and citalopram, and the antibiotic azithromycin. Other contaminants raising concern are endocrine disrupters (EDCs) which are chemicals that may interfere with the body's hormonal gland system and cause various adverse effects. "Spanish consumers had the highest intake of endocrine disrupting compounds from seafood consumption, though the assessed intake was still below the tolerable weekly intake", explains Sara Rodriguez-Mozaz, researcher working at the Catalan Institute of Water Research (ICRA) in Girona, Spain, "Methylparaben, triclosan and bisphenol A were the most frequently detected EDCs." Other substances investigated by the researchers are microplastics (plastic particles smaller than 5 mm) that may act as a vector for chemical contaminants. The research revealed that up to 36.5% of the fish examined and 83% of crustaceans contained microplastics. The main challenges in the project were related to finding the right analytical methods. "Pharmaceutical and EDCs are found at very low levels in seafood, close to the current limits of detection of conventional analytical methodologies," says Rodriguez-Mozaz. The scientists collated their results in a database focusing "on unregulated contaminants that give rise to concern from an environmental and public health point of view". They invite "policy makers" to use their study "to help inform policy and advisory guidelines" and "authorities to highlight the deficits in seafood contaminant research". However, there is a happy ending. Despite the increase of chemicals in the marine environment, the low levels in seafood so far mean that we can still enjoy seafood during our Christmas holidays without worrying too much. Explore further: New screening, detection and extraction methods for priority contaminants in seafood


Cerrone F.,Institute of Water Research | del Mar Sanchez-Peinado M.,Institute of Water Research | Juarez-Jimenez B.,Institute of Water Research | Juarez-Jimenez B.,University of Granada | And 4 more authors.
Journal of Microbiology and Biotechnology | Year: 2010

Azotobacter chroococcum H23 (CECT 4435), Azotobacter vinelandii UWD, and Azotobacter vinelandii (ATCC 12837), members of the family Pseudomonadaceae, were used to evaluate their capacity to grow and accumulate polyhydroxyalkanoates (PHAs) using two-phase olive mill wastewater (TPOMW, alpeorujo) diluted at different concentrations as the sole carbon source. The PHAs amounts (g/l) increased clearly when the TPOMW samples were previously digested under anaerobic conditions. The MNR analysis demonstrated that the bacterial strains formed only homopolymers containing β-hydroxybutyrate, either when grown in diluted TPOMW medium or diluted anaerobically digested TPOMW medium. COD values of the diluted anaerobically digested waste were measured before and after the aerobic PHA-storing phase, and a clear reduction (72%) was recorded after 72 h of incubation. The results obtained in this study suggest the perspectives for using these bacterial strains to produce PHAs from TPOMW, and in parallel, contribute efficiently to the bioremediation of this waste. This fact seems essential if bioplastics are to become competitive products.


Gonzalez-Martinez A.,University of Granada | Leyva-Diaz J.C.,University of Granada | Rodriguez-Sanchez A.,Institute of Water Research | Munoz-Palazon B.,Institute of Water Research | And 4 more authors.
Biofouling | Year: 2015

A bench-scale pure moving bed bioreactor-membrane bioreactor (MBBR-MBR) used for the treatment of urban wastewater was analyzed for the identification of bacterial strains with the potential capacity for calcium carbonate and struvite biomineral formation. Isolation of mineral-forming strains on calcium carbonate and struvite media revealed six major colonies with a carbonate or struvite precipitation capacity in the biofouling on the membrane surface and showed that heterotrophic bacteria with the ability to precipitate calcium carbonate and struvite constituted ~7.5% of the total platable bacteria. These belonged to the genera Lysinibacillus, Trichococcus, Comamomas and Bacillus. Pyrosequencing analysis of the microbial communities in the suspended cells and membrane biofouling showed a high degree of similarity in all the samples collected with respect to bacterial assemblage. The study of operational taxonomic units (OTUs) identified through pyrosequencing suggested that ~21% of the total bacterial community identified in the biofouling could potentially form calcium carbonate or struvite crystals in the pure MBBR-MBR system used for the treatment of urban wastewater. © 2015 Taylor & Francis.

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