Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2022
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No abstract has been registered
Abstract
The large brown seaweeds (kelps) are potential sources of protein for animal feed. They have lower protein contents than most red and green algae, but due to potential for large-scale production, they may represent a significant future protein source. The impact of pH, temperature and polysaccharide-degrading enzymes on the solubility and extraction yields of protein from wet Saccharina latissima biomass was investigated. The protein solubility increased with increasing pH and reached maximum of 23% at pH 11, determined as total amino acids (TAA). The enzyme treatments increased the release of soluble compounds by 30–35%. The highest protein yield obtained was 19%, using a ratio of water to wet seaweed of 1:1 for extraction. Even if the yields can be increased by increasing the water amounts used for extraction, the majority of the protein would remain in the insoluble residue after separation. The strategy for production of a larger quantity of protein-enriched biomass was therefore to maintain the insoluble fraction as the product. A pilot scale production was carried out, also including the red algae Palmaria palmata. In total 750 kg S. latissima and 195 kg P. palmata were processed. The protein content in the product increased from 10 to 20% of dry weight (dw) for S. latissima and from 12 to 28% for P. palmata, with yields of 79 and 69%, respectively. The ash content was reduced from 44 to 26% and from 12 to 5% of dw, respectively, for the two species. The main protein loss was free amino acids, which constituted approximately 10% of TAA in the feedstocks. Less essential than non-essential amino acids were lost, thus, the essential amino acids were enriched in the product.
Abstract
Kelp forests in the North Atlantic are at risk of decline at their warm temperature distribution margins due to anthropogenic temperature rise and more frequent marine heat waves. To investigate the thermal adaptation of the cold-temperate kelp Laminaria digitata, we sampled six populations, from the Arctic to Brittany (Spitsbergen, Tromsø, Bodø [all Norway], Helgoland [Germany], Roscoff and Quiberon [both France]), across the species’ entire distribution range, spanning 31.5° latitude and 12-13°C difference in mean summer sea surface temperature. We used pooled vegetative gametophytes derived from several sporophytes to approximate the genetic diversity of each location. Gametophytes were exposed to (sub-) lethal high (20-25°C) and (sub-) optimal low (0-15°C) temperature gradients in two full-factorial, common-garden experiments, subjecting subsets of populations from different origins to the same conditions. We assessed survival of gametophytes, their ability to develop microscopic sporophytes, and subsequent growth. We hypothesized that the thermal performance of gametophytes and microscopic sporophytes corresponds to their local long-term thermal history. Integrated gametophyte survival revealed a uniform upper survival temperature (UST) of 24°C among five tested populations (Tromsø to Quiberon). In contrast, following two weeks of thermal priming of gametophytes at 20-22°C, sporophyte formation at 15°C was significantly higher in southern populations (Quiberon and Roscoff) compared to the high-latitude population of Tromsø. Between 0-15°C, survival of the Arctic population (Spitsbergen) was negatively correlated with increasing temperatures, while the southern-most population (Quiberon) showed the opposite. Thus, responses of survival at low, and sporophyte formation at high temperatures, support the concept of local adaption. On the other hand, sporophyte formation between 0-15°C peaked at 6-9°C in the Quiberon and at 9-12°C in the Spitsbergen population. Sporophyte growth rates (GR) both in length and width were similar for Spitsbergen, Tromsø and Quiberon; all had maximum GRs at 12-15°C and low GRs at 0-6°C. Therefore, responses of sporophyte formation and growth at low temperatures do not reflect ecotypic adaptation. We conclude that L. digitata populations display trait-dependent adaptation, partly corresponding to their local temperature histories and partly manifesting uniform or unpredictable responses. This suggests differential selection pressures on the ontogenetic development of kelps such as L. digitata.
Abstract
No abstract has been registered
Authors
David Renaudeau Søren Krogh Jensen Morten Ambye-Jensen Steffen Adler Paolo Bani Eric Juncker Lene StødkildeAbstract
In organic pig production systems, one of the main challenges is to meet the demand for resources rich in protein. Among the resources available, temperate green plants, such as forage legumes, are potential sources of energy and protein. The aim of the study was to determine the nutritional value of silages (S) from the whole plant of lucerne (L) and red clover (R) and protein pastes (PPs) obtained from L and R leaves. In a first trial, 30 pigs were used in a factorial design to determine the total tract digestibility (TTD) of dietary nutrients and energy in five dietary treatments. The control group was fed a control diet (C1). The lucerne silage (LS) and red clover silage (RS) groups were fed a 78%:22% mixture (on a DM basis) of the C1 diet and LS or RS. The lucerne protein paste (LPP) and the red clover protein paste (RPP) groups were fed an 81%:19% mixture (on a DM basis) of the C1 diet and LPP or RPP. In the second trial, five pigs were used in a 5 × 5 Latin square design to evaluate the standardised ileal digestibility (SID) of amino acids (AAs) in the four legume products. The control diet (C2) was formulated with casein as the sole protein source. The LS and RS groups were fed an 85%:15% mixture (on a DM basis) of the C2 diet and LS or RS. The LPP and RPP groups were fed an 80%:20% mixture (on a DM basis) of the C2 diet and LPP or RPP. Regardless of the plant species, silages obtained from L and R leaves contained less AA and more fibre than protein pastes. While the fresh forages contained the same percentage of protein N in total N (63.6%), lucerne lost more protein N during ensiling than red clover (−75.5 vs −33.8%). The calculated TTD coefficient of energy was higher in silages than in protein pastes and lower in R than in L products (72.8, 71.5, 67.7, and 61.3 for LS, RS, LPP and RPP, respectively). The SID of total essential AA was higher in LPP than in RPP (87.2 vs 79.2%) whereas it was lower in LS than in RS (33.2 vs 56.8%). The lower SID values in silages were explained by the protein degradation during the ensiling process and a high proportion of AA linked to the NDF fraction. The results of the present study show that protein pastes obtained from lucerne and red clover are valuable protein sources for pig. In contrast, legume silages have to be considered as an energy source rather than a protein source.
Abstract
Berries of the genus Vaccinium are highly valued health-beneficial superfoods, which are commonly subjected to adulteration and mixed with each other, or with other common berry species. A quantitative DNA-based method utilizing a chip-based digital polymerase chain reaction (dPCR) technique was developed for identifying and quantifying wild lingonberry (V. vitis-idaea) and cultivated American cranberry (V. macrocarpon). The dPCR method with species-specific primers for mini-barcoding was designed based on the indel regions found in the trnI-CAU–trnL-CAA locus in the chloroplast genome. The designed primers were able to amplify only target species, enabling to distinguish the two closely related species with good sensitivity. Our results illustrated the ability of the method to identify lingonberry and American cranberry DNA using PCR without the need for probes or further sequencing. The dPCR method could also quantify the DNA copy number in mixed samples. Based on this study, the method provides a basis for a simple, fast, and sensitive quantitative authentication analysis of lingonberry and American cranberry by dPCR. Moreover, it can also provide a platform for authentication analyses of other plant species as well by utilizing the indel regions of chloroplast genomes.
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No abstract has been registered
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No abstract has been registered
Authors
Sigridur DalmannsdottirAbstract
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Authors
Randi Berland FrøsethAbstract
No abstract has been registered