Peer-reviewed articles

Twenty-two novel microsatellite loci for lumpfish (Cyclopterus lumpus)

Lumpfish (Cyclopterus lumpus L. 1758) are widely distributed on both sides of the North Atlantic. They are a commercially important species, but stock size estimates have declined since the mid-1980s in Canada, Norway and Iceland. Little is known about the biology of this species, in particular the breeding migrations and population structure which are fundamental for effective management. This paper describes the development and characterization of twenty-two polymorphic microsatellite loci using next generation sequencing. The number of alleles per locus ranged from 3 to 27 in two geographically distant North Atlantic populations, with observed and expected heterozygosities ranging between 0.0625–0.979 and 0.0618–0.946, respectively. These loci are an important resource that will allow assessment of the population genetic structure of this species, and contribute to its appropriate management.

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Peer-reviewed articles

Litorilinea aerophila gen. nov., sp. nov., an aerobic member of class Caldilineae, phylum Chloroflexi, isolated from an intertidal hot spring

A thermophilic, aerobic, Gram-stain-negative, filamentous bacterium, strain PRI-4131T, was isolated from an intertidal hot spring in Isafjardardjup, NW Iceland. The strain grew chemo-organotrophically on various carbohydrates. The temperature range for growth was 40–65 ° C (optimum 55 ° C), the pH range was pH 6.5–9.0 (optimum pH 7.0) and the NaCl range was 0–3 % (w / v) (optimum 0.5 %) . Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain PRI-4131T represented a distinct lineage within the class Caldilineae of the phylum Chloroflexi. The highest levels of sequence similarity, about 91 %, were with Caldilinea aerophila STL-6-O1T and Caldilinea tarbellica D1-25-10-4T. Fermentative growth was not observed for strain PRI-4131T, which, in addition to other characteristics, distinguished it from the two Caldilinea species. Owing to both phylogenetic and phenotypic differences from the described members of the class Caldilineae , we propose to accommodate strain PRI-4131T in a novel species in a new genus, Litorilinea aerophila gen. nov., sp. nov. The type strain of Litorilinea aerophila is PRI-4131T (= DSM 25763T = ATCC BAA-2444T).

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Peer-reviewed articles

Fish, contaminants and human health: Quantifying and weighing benefits and risks

This paper describes a quantitative risk – benefit assessment of fish consumption. We compare the net health effect expressed in DALYs of two scenarios. The reference scenario is the current fish intake of the Dutch population, which is less than what is recommended by the health authorities. The alternative scenario describes the health effects if the population consumes 200 g of fish per week, which is close to the recommendation. All health effects due to fish consumption for which there is convincing evidence are incorporated in the assessment. The QALIBRA software (www.qalibra.eu) is used to simulate the two scenarios. The results show there is a net benefit for the population if it consumes 200 g of fish each week.

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Peer-reviewed articles

Fish consumption during child bearing age: A quantitative risk – benefit analysis on neurodevelopment

The fish ingredient N3-docosahexaenoic acid 22: 6 n-3 (DHA) stimulates brain development. On the other hand methylmercury (MeHg) in fish disturbes the developing central nervous system.

In this Context the IQ score in children is considered as an aggregate measure of in utero brain development.

To determine the effect of DHA exposure on prenatal neurodevelopment the maternal DHA intake during pregnancy was compared with its epidemiologically observed effect on the IQ score of children.

For MeHg the maternal intake was converted into its accumulation in the maternal body. The maternal body burden then was compared with its epidemiologically observed relationship with the IQ score.

Taking the MeHg and DHA content of 33 fish species the net effect of these compounds on the IQ score was quantified. For most fish species the adverse effect of MeHg on the IQ score exceeded the beneficial effect of DHA. In the case of long-living predators a negative effect up to 10 points on the IQ score was found.

The results of this study indicate that food interventions aiming at the beneficial effects of fish consumption should focus on fish species with a high DHA content, while avoiding fish species with a high MeHg content.

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Peer-reviewed articles

Injection of fish protein solutions of fresh saithe (Pollachius virens) fillets studied by low field Nuclear Magnetic Resonance and physicochemical measurements

Low field Nuclear Magnetic Resonance was used in comparison to yield and physicochemical measurements to assess the effects of salt and protein injection on the properties of saithe (Pollachius virens) fillets during chilled and frozen storage. Saithe fillets injected with various combinations of salt, homogenized fish proteins, gelatin and fish protein hydrolyzate, were compared to the properties of untreated fillets. Addition of salt or fish protein hydrolyzate resulted in increased yield after cooking and water holding capacity compared to other treatments. Transversal relaxation data fitting resulted in three water populations with relaxation times of 27–45 ms, 60–99 ms and 187–341 ms. Relaxation times and respective populations showed significant correlation to various physicochemical properties, that muscle water behavior was changed by salt and protein injection and indicated protein denaturation during frozen storage. Fish protein hydrolyzate injected fillets were most stable through storage, while gelatin injected fillets were most denatured during frozen storage.

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Peer-reviewed articles

Effects of added phosphates on lipid stability during salt curing and rehydration of cod (Gadus morhua)

Effects of added phosphates on retardation of lipid oxidation of salted cod during processing, storage and after rehydration were investigated. Lipid hydrolysis progress and development of color, primary and secondary lipid oxidation products and fluorescence intensities were determined. Added phosphates significantly retarded lipid hydrolysis and lipid oxidation progress, resulting in lower free fatty acid, lipid hydroperoxides (PV), thiobarbituric acid-reactive substances (TBARS) as well as fluorescence intensities (δF or and δF aq). Significant correlation between the lipid oxidation products (PV, TBARS, δF or and δF aq) and yellow / brownish discoloration (b * value) of salted cod was observed. Principal component analysis showed that TBARS, b * value and δF or were the strongest indicators of lipid oxidation during salting and storage.

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Peer-reviewed articles

Spatial and teporal trends of contaminants in mussel sampled around the Icelandic coastline

Contaminants have been determined in blue mussels (Mytilus edulis) at 11 locations around the Icelandic coastline from 1990 to 2010. The aim of the present study was to investigate if there has been a change in concentration of contaminants around the Icelandic coastline for the last two decades and if the concentrations and changes, if present , were consistent between locations. Concentrations of the persistent organic pollutants, p, p′-Dichlorodiphenyldichloroethene (p, p′ -DDE), hexachlorobenzene (HCB), α-hexachlorocyclohexane (α-HCH), polychlorinated biphenyl (PCB-153) and trans-nonachlor, have decreased at most of the sampling locations in Iceland in recent years. However, an increasing trend was found at a few locations that could be explained by anthropogenic activity. The concentration levels of the persistent organics were much lower than found at the Norwegian, USA and Chinese coasts, especially levels of p, p′ -DDE. The concentration of copper and selenium had a consistent pattern of change and concentration between locations over the period which showed a decreasing trend in recent years. The trace elements arsenic, cadmium, mercury and zinc showed more variation in concentration between locations, the concentration of arsenic, mercury and zinc was fairly stable over the period, whereas there were fluctuations in cadmium concentrations. The concentrations of cadmium and zinc were observed to be somewhat higher than found in mussels from Norway, USA and China but values of mercury and lead were much lower in the mussel sampled in Iceland. The higher concentrations of cadmium and zinc can be explained by the volcanic activity in Iceland but no major anthropogenic sources of trace elements are known in Iceland.

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Peer-reviewed articles

Browsing metagenomes for novel starch and carbohydrate industry enzymes - AMYLOMICS case study

The rapid progress in DNA sequencing technology is resulting in exponential growth in the volume of genome and metagenome sequences. In many cases, standard bioinformatics methods can assign genes to a family, but the exact function of the encoded protein remains unknown. Moreover, the generation of high quality DNA sequence is disproportionately time consuming and expensive. It is, therefore, important to develop methods for the structural and functional automatic annotation for the analysis of lower quality sequence starting from DNA reads. We have developed MEGGASENSE platform for the functional and structural automatic annotation of metagenomes / genomes. The initial functional analysis is carried out on reads before read assembly using in silico translation. However, unlike most other platforms, the resulting protein sequences are scanned using HMMs, which results in more effective detection of genes. Depending on the aims of the analysis, it is possible to use a generic library of profiles or a custom database of choice. The reads are subsequently being assembled. The assembled sequences can be used for 'gene of interest' analysis by BLAST within the platform. Finally, the user can browse the sequences with the Solr search engine, which is implemented within the graphical user interface. The utility of the MEGGASENSE will be illustrated with examples including metagenomes composed of novel anaerobic or microaerophilic heterotrophic species from thermophilic habitats that cover a range of physicochemical conditions. Using MEGGASENSE over 350 reads / genes potentially expressing carbohydrate-modifying enzymes were discovered showing identities ranging from 26 to 100% to genes present in GenBank.

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Peer-reviewed articles

Effects of Injection of protein solutions prepared from fish by-products on yield and chemical properties of chilled and frozen saithe (Pollachius virens) fillets

Fish gelatin and protein solutions prepared from saithe by-products were injected into saithe fillets. Effects on weight changes, water holding capacity, and chemical composition of the fillets were investigated after chilled (2, 5, and 7 days) and frozen (14 and 49 days) storage. The results showed that higher weight yields were obtained by adding proteins and salt to the fillets in comparison with only salt, especially in chilled fillets. The drawback of the injection was that higher drip losses were found during storage and thawing than for untreated fillets. Effects of injection on water content were only significant after 2 days of chilled storage, but differences leveled out after longer storage time and with freezing and thawing of the fillets. The procedure applied in this study seems to be promising for utilization of by-products such as trimmings as an ingredient in higher value products like fillets, in comparison to mince products.

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Peer-reviewed articles

Quantitative methods for decision support in the Icelandic fishing industry

Modern fisheries already collect vast amount of data, for example, through ERP systems and electronic log-books. It is however well known that the data are rarely used for improving operational decision making. By converting this data into useable information, decision making in the fishing industry could be improved. This paper attempts to show that quantitative methods can be of use in many aspects of decision making in the fishing industry. The paper proposes a hierarchically structured decision support process based on two different optimization models for supporting the long- and short-term decision making in fisheries. For long-term planning the paper proposes a linear optimization model that describes the entire operation of a vertically integrated seafood company. For short-term decision making the paper proposes a mixed integer linear optimization model to assist in organizing vessel trips and deciding catch location with regard to raw material quality and yield obtained in processing.

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