Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2021
Forfattere
Jose Antonio Vazquez Carolina Hermida-Merino Daniel Hermida-Merino Manuel M. Piñeiro Johan Johansen Carmen G. Sotelo Ricardo I. Perez-Martin Jesus ValcarcelSammendrag
Salmon processing commonly involves the skinning of fish, generating by-products that need to be handled. Such skin residues may represent valuable raw materials from a valorization perspective, mainly due to their collagen content. With this approach, we propose in the present work the extraction of gelatin from farmed salmon and further valorization of the remaining residue through hydrolysis. Use of different chemical treatments prior to thermal extraction of gelatin results in a consistent yield of around 5%, but considerable differences in rheological properties. As expected from a cold-water species, salmon gelatin produces rather weak gels, ranging from 0 to 98 g Bloom. Nevertheless, the best performing gelatins show considerable structural integrity, assessed by gel permeation chromatography with light scattering detection for the first time on salmon gelatin. Finally, proteolysis of skin residues with Alcalase for 4 h maximizes digestibility and antihypertensive activity of the resulting hydrolysates, accompanied by the sharpest reduction in molecular weight and higher content of essential amino acids. These results indicate the possibility of tuning salmon gelatin properties through changes in chemical treatment conditions, and completing the valorization cycle through production of bioactive and nutritious hydrolysates.
Forfattere
Leticia Regueiro Richard Newton Mohamed Soula Diego Méndez Björn Kok David C. Little Roberto Pastres Johan Johansen Martiña FerreiraSammendrag
EU aquaculture produces only a small fraction of the internal demand of aquatic foods, but boosting this activity must be done in compliance with high standards of environmental protection and social benefits, as fostered by the policies on circular economy recently launched by the EU. Nevertheless, the assessment of the environmental sustainability of aquaculture and other food production systems is complex, due to the different tools and approaches available. Moreover, the current EU regulatory framework may be restricting the options to implement some circular solutions. This paper examines the controversies related to the assessment of environmental impacts of aquaculture processes and the different available circular solutions, with a focus on the best options to valorize aquaculture side streams and how current regulatory burdens and gaps should be solved.
Forfattere
Ying Yen Martin Riis Weisbjerg Ralf Rautenberger Adriána Fečkaninová Margarita Novoa-GarridoSammendrag
Rapid deterioration of harvested macroalgal biomass is a challenge for macroalgal industry and can be overcome with the inexpensive ensiling preservation. To improve silage quality, Saccharina latissima and Alaria esculenta biomass was subjected to ensiling conditions following a 2 × 4 factorial design, with 2 prewilting treatments (no-prewilting and prewilted to 300 g DM kg−1 fresh biomass) and 4 additive treatments (no additive, formic acid, single and two species of Lactobacillus inoculant), and ensiled for 3 or 12 months at 15 °C. Acetate was the main fermentation product in these seaweed silages. Prewilting reduced the acetate, mannitol, and NH3 content in silages. In S. latissima silages without additives, prewilting led to less acidification (pH = 5.7). Also, prewilting caused protein and phlorotannin degradation. When treated with formic acid, the silage pH was below 4 regardless of the biomass’s moisture content. The use of Lactobacillus spp. inoculants was essential for lactate production in seaweed silages, and it significantly lowered silage pH in S. latissima and prewilted A. esculenta compared to silages with no additives. A high level of the phlorotannin content was preserved (> 90%) in the 3-month A. esculenta silages without prewilting. However, major reduction of antioxidant activity was observed in 12-month silages in both seaweed species. In conclusion, ensiling is a viable method for preserving Alaria and Saccharina biomass. Prewilting restricted silage fermentation, and both formic acid and bacterial additives facilitated silage acidification. However, there was no clear benefit of these treatments in preserving the antioxidant activity.
Forfattere
Ying Yen Ralf Rautenberger Martin Riis Weisbjerg Adriána Fečkaninová Margarita Novoa-GarridoSammendrag
Det er ikke registrert sammendrag
Forfattere
Alexander Jüterbock Antoine J. P. Minne J. Mark Cock Melinda Ann Coleman Thomas Wernberg Lydia Scheschonk Ralf Rautenberger Jie Zhang Zi-Min HuSammendrag
Marine macrophytes, including seagrasses and macroalgae, form the basis of diverse and productive coastal ecosystems that deliver important ecosystem services. Moreover, western countries increasingly recognize macroalgae, traditionally cultivated in Asia, as targets for a new bio-economy that can be both economically profitable and environmentally sustainable. However, seagrass meadows and macroalgal forests are threatened by a variety of anthropogenic stressors. Most notably, rising temperatures and marine heatwaves are already devastating these ecosystems around the globe, and are likely to compromise profitability and production security of macroalgal farming in the near future. Recent studies show that seagrass and macroalgae can become less susceptible to heat events once they have been primed with heat stress. Priming is a common technique in crop agriculture in which plants acquire a stress memory that enhances performance under a second stress exposure. Molecular mechanisms underlying thermal priming are likely to include epigenetic mechanisms that switch state and permanently trigger stress-preventive genes after the first stress exposure. Priming may have considerable potential for both ecosystem restoration and macroalgae farming to immediately improve performance and stress resistance and, thus, to enhance restoration success and production security under environmental challenges. However, priming methodology cannot be simply transferred from terrestrial crops to marine macrophytes. We present first insights into the formation of stress memories in both seagrasses and macroalgae, and research gaps that need to be filled before priming can be established as new bio-engineering technique in these ecologically and economically important marine primary producers.
Sammendrag
Seaweeds are increasingly used in European cuisine. Until the recent use of molecular techniques, species identification was solely based on morphology which cannot easily discriminate morphologically simple but phenotypically plastic taxa such as the green algal genus Ulva. For example, current taxonomic protocol effectively reassigned the previously known European ʻUlva lactuca L.’ under the name Ulva fenestrata Postels & Ruprecht. Also, the presumptive Ulva lactuca approved by the Institute for Reference Materials and Measurements (IRMM, Joint Research Center, European Commission) as Certified Reference Material (CRM) for analytical quality assurance was genetically identified as U. rigida C.Agardh. It is very likely that different Ulva species under various names have been consumed as food not only in Europe, but also worldwide. In this regard, when chemical composition and nutritional quality of different seaweed species meet a set of food standard criteria, and food safety hazards are mitigated, they should be endorsed for consumption. In the case of Ulva, we propose that different bladed and tubular species should generally be accepted for food consumption in Europe.
Sammendrag
Macrocystis pyrifera is a major habitat forming kelp in coastal ecosystems of temperate regions of the northern and southern hemispheres. We investigated the seasonal occurrence of adult sporophytes, morphological characteristics, and reproductive phenology at two sites within a wave-protected harbour and two wave-exposed sites in southern New Zealand every 3–4 months between 2012 and 2013. Seasonality in reproduction was assessed via the number of sporophylls, the occurrence of sori on sporophylls, and non-sporophyllous laminae (fertile pneumatocyst-bearing blades and fertile apical scimitars), meiospore release, and germination. We found that M. pyrifera was present and reproductive year-round in three of the four sites, and patterns were similar for the wave-exposure conditions. Sori were found on pneumatocyst-bearing blades and apical scimitars in addition to the sporophylls, and viable meiospores were released from all three types of laminae. Morphological variations between sites with different wave exposure indicate that sporophytes from wave-protected sites have bigger blades and holdfasts and are longer than those from wave-exposed sites. We discuss the implications of these biological variables for the ecology of M. pyrifera inhabiting different wave exposure environments in southern New Zealand.
Sammendrag
Kelps are important foundation species in coastal ecosystems currently experiencing pronounced shifts in their distribution patterns caused by ocean warming. While some populations found at species’ warm distribution edges have been recently observed to decline, expansions of some species have been recorded at their cold distribution edges. Reduced population resilience can contribute to kelp habitat loss, hence, understanding intraspecific variations in physiological responses across a species’ latitudinal distribution is crucial for its conservation. To investigate potential local responses of the broadly distributed kelp Saccharina latissima to marine heatwaves in summer, we collected sporophytes from five locations in Europe (Spitsbergen, Bodø, Bergen, Helgoland, Locmariaquer), including populations exposed to the coldest and warmest local temperature regimes. Meristematic tissue from sporophytes was subjected to increasing temperatures of 1+2, 1+4 and 1+6 ◦C above the respective mean summer temperatures (control, 1±0 ◦C) characteristic for each site. Survival and corresponding physiological and biochemical traits were analyzed. Vitality (optimum quantum yield, Fv/Fm) and growth were monitored over time and biochemical responses were measured at the end of the experiment. Growth was highest in northern and lowest in southern populations. Overall, northern populations from Spitsbergen, Bodø and Bergen were largely unaffected by increasing summer temperatures up to 1+6 ◦C. Conversely, sporophytes from Helgoland and Locmariaquer were markedly stressed at 1+6 ◦C: occurrence of tissue necrosis, reduced Fv/Fm, and a significantly elevated de-epoxidation state of the xanthophyll cycle (DPS). The variations in phlorotannins, mannitol and tissue C and N contents were independent of temperature treatments and latitudinal distribution pattern. Pronounced site-specific variability in response to increasing temperatures implies that exceeding a threshold above the mean summer temperature exclusively affect rear-edge (southernmost) populations.
Forfattere
Michael Roleda Sandra Lage Daniel Fonn Aluwini Celine Rebours May Bente Brurberg Udo Nitschke Francesco G. GentiliSammendrag
Det er ikke registrert sammendrag
2020
Forfattere
Ralf RautenbergerSammendrag
The commercial cultivation of marine macroalgae is a young and rapidly growing industry sector in Norway. Although it is currently limited to a few brown macroalgae, other species such as the green marine macroalga Ulva fenestrata (formerly Ulva lactuca) has also a high potential for an industrial biomass production, for example to be used for the food marked. However, this process is strongly affected by the presence of marine diatoms transported along with the seawater into the cultivation system of U. fenestrata. These diatoms not only proliferate in the water tanks, they also colonise the green macroalgal biomass with many brown spots, which reduces its value for the food marked significantly. This presentation shows the results of a project that studied the use of germanium dioxide (GeO2) as a known growth inhibitor of diatoms to control their contamination during the biomass production process of U. fenestrata. First, the co-occurring diatom was morphologically identified as Fragilaria sp. using light microscopy. Thereafter, a dose-response experiment was conducted to reveal the concentrations of GeO2, resulting in an effective growth inhibition of Fragilaria sp. Based on this knowledge, the impact of different GeO2 concentrations was studied on how the photophysiolgy (photosynthetic characteristics, pigment patterns) and growth of U. fenestrata are affected in both small-scale (2 L) and large-scale (100 L) cultivation systems. An effective control of the proliferation of Fragilaria sp. during the cultivation process of U. fenestrata may result in the production a high-quality biomass with a high value for the food marked.