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.

2022

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Sammendrag

Microalgal biomass is widely studied for its possible application in food and human nutrition due to its multiple potential health benefits, and to address raising sustainability concerns. An interesting field whereby to further explore the application of microalgae is that of beer brewing, due to the capacity of some species to accumulate large amounts of starch under specific growth conditions. The marine species Tetraselmis chui is a well-known starch producer, and was selected in this study for the production of biomass to be explored as an active ingredient in beer brewing. Cultivation was performed under nitrogen deprivation in 250 L tubular photobioreactors, producing a biomass containing 50% starch. The properties of high-starch microalgal biomass in a traditional mashing process were then assessed to identify critical steps and challenges, test the efficiency of fermentable sugar release, and develop a protocol for small-scale brewing trials. Finally, T. chui was successfully integrated at a small scale into the brewing process as an active ingredient, producing microalgae-enriched beer containing up to 20% algal biomass. The addition of microalgae had a noticeable effect on the beer properties, resulting in a product with distinct sensory properties. Regulation of pH proved to be a key parameter in the process.

Sammendrag

Reusing soil can reduce environmental impacts associated with obtaining natural fresh soil during road construction and analogous activities. However, the movement and reuse of soils can spread numerous plant diseases and pests, including propagules of weeds and invasive alien plant species. To avoid the spread of barnyardgrass in reused soil, its seeds must be killed before that soil is spread to new areas. We investigated the possibility of thermal control of barnyardgrass seeds using a prototype of a stationary soil steaming device. One Polish and four Norwegian seed populations were examined for thermal sensitivity. To mimic a natural range in seed moisture content, dried seeds were moistened for 0, 12, 24, or 48 h before steaming. To find effective soil temperatures and whether exposure duration is important, we tested target soil temperatures in the range 60 to 99 C at an exposure duration of 90 s (Experiment 1) and exposure durations of 30, 90, or 180 s with a target temperature of 99 C (Experiment 2). In a third experiment, we tested exposure durations of 90, 180, and 540 s at 99 C (Experiment 3). Obtaining target temperatures was challenging. For target temperatures of 60, 70, 80, and 99 C, the actual temperatures obtained were 59 to 69, 74 to 76, 77 to 83, and 94 to 99 C, respectively. After steaming treatments, seed germination was followed for 28 d in a greenhouse. Maximum soil temperature affected seed germination, but exposure duration did not. Seed premoistening was of influence but varied among temperatures and populations. The relationships between maximum soil temperature and seed germination were described by a common dose–response function. Seed germination was reduced by 50% when the maximum soil temperature reached 62 to 68 C and 90% at 76 to 86 C. For total weed control, 94 C was required in four populations, whereas 79 C was sufficient in one Norwegian population.

Sammendrag

Aksjon pærebrann” ble etter den første påvisning av pærebrann i Norge i 1986 opprettet som et samarbeidsprosjekt mellom Mattilsynet og NIBIO (Norsk Institutt for Bioøkonomi, Divisjon for Bioteknologi og Plantehelse). Formålet med prosjektet er å overvåke, kartlegge og bekjempe pærebrann. For å oppnå et best mulig resultat i dette arbeidet er den delen av landet der pærebrann forekommer blitt delt opp i tre soner. 1. Pærebrannsone Omfatter områder/kommuner av landet hvor det er blitt påvist pærebrann og hvor det ikke er et mål å utrydde sjukdommen. 2. Bekjempelsessone Omfatter områder/kommuner hvor det er blitt påvist pærebrann og som grenser til kommuner i pærebrannsonen. Her gjøres intensivert overvåking og rydding med formål å hindre videre spredning og på sikt å utrydde sjukdommen. 3. Forebyggende sone Dette er områder uten pærebrann, som er i nærheten av smittefronten og er områder med viktig kommersiell fruktdyrking eller områder i nærheten av slik fruktproduksjon Hensikten er ha en buffer mot spredning til viktige fruktområder eller til andre deler av landet. . I disse områdene skjer overvåkingen på stikkprøvebasis. Friske planter av bulkemispel og pilemispel vil kunne bli fjernet som et forebyggende tiltak I tillegg til disse tre sonene gjennomføres overvåking på stikkprøvebasis i andre deler av landet der pærebrann ikke er påvist. Kommune- og fylkesinndeling er i hovedsak basert på den nye kommune og fylkesinndelingen. Fra 2021 iverksatte Mattilsynet en ny forskrift med inndeling av kommuner og fylker med mange nye navn. Forskrift om kontrollområder for å forebygge, begrense og bekjempe pærebrann (Erwinia amylovora)er tilgjengelig på https://lovdata.no/dokument/SF/forskrift/2020-01-08-51.. Forsrkriften ble sist revidert 5.10.2021 som følge av påvisningene som ble gjort i nye områder i 2021. Med hovedvekt på de viktigste vertplantene ble det i 2021 (2020 tall i parentes) gjort systematisk stikkprøvekontroll i 8 (10) fylker og 100 (140) kommuner. Det ble lagt spesielt vekt på kontroller i fruktdyrkingsområder, planteskoler, planteutsalg og områder rundt disse. Samt å rydde pærebrann i randområder, som f.eks. Grimstad. Til sammen ble det utført 13 954 (14 310) inspeksjoner av vertplanteforekomster. Totalt er det ryddet på 3 069 (1 407) eiendommer. I flere smittede områder har det vært gjennomført systematisk gjennomgang og fjerning av alle registrerte sjuke planter. Men i kommunene Ålesund, Klepp, Gjesdal, Sandnes, Stavanger, Sola, Karmøy, Haugesund, Askøy, Os, Bergen og Kristiansand er pærebrann nå så utbredt at ressursene ikke strekker til for å fjerne planter med smitte. Ellers i smittede områder ble stort sett alle sjuke planter som var registrert, fjernet. I kommersielle frukthager i Norge ble det i 2021 ikke påvist pærebrann noen steder. Tallet på lokaliteter som har blitt ryddet er betydelig større enn i 2020. Dette skyldes mye arbeidet i randsoner for pærebrann, samt mer omfattende rydding rundt planteskole/planteutsalg. Men fortsatt er det mye rydding i såkalte friområder, som er tidkrevende og gir lavere ryddetall. Når det gjelder stikkprøvekontrollen, er denne om lag som i 2020......

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Sammendrag

Tetraselmis chui is known to accumulate starch when subjected to stress. This phenomenon is widely studied for the purpose of industrial production and process development. Yet, knowledge about the metabolic pathways involved is still immature. Hence, in this study, transcription of 27 starch-related genes was monitored under nitrogen deprivation and resupply in 25 L tubular photobioreactors. T. chui proved to be an efficient starch producer under nitrogen deprivation, accumulating starch up to 56% of relative biomass content. The prolonged absence of nitrogen led to an overall down-regulation of the tested genes, in most instances maintained even after nitrogen replenishment when starch was actively degraded. These gene expression patterns suggest post-transcriptional regulatory mechanisms play a key role in T. chui under nutrient stress. Finally, the high productivity combined with an efficient recovery after nitrogen restitution makes this species a suitable candidate for industrial production of high-starch biomass.

Sammendrag

Over recent decades, the Norwegian cereal industry has had major practical and financial challenges associated with the occurrence of Fusarium head blight (FHB) pathogens and their associated mycotoxins in cereal grains. Deoxynivalenol (DON) is one of the most common Fusarium-mycotoxins in Norwegian oats, however T-2 toxin (T2) and HT-2 toxin (HT2) are also commonly detected. The aim of our study was to rank Nordic spring oat varieties and breeding lines by content of the most commonly occurring Fusarium mycotoxins (DON and HT2 + T2) as well as by the DNA content of their respective producers. We analyzed the content of mycotoxins and DNA of seven fungal species belonging to the FHB disease complex in grains of Nordic oat varieties and breeding lines harvested from oat field trials located in the main cereal cultivating district in South-East Norway in the years 2011–2020. Oat grains harvested from varieties with a high FHB resistance contained on average half the levels of mycotoxins compared with the most susceptible varieties, which implies that choice of variety may indeed impact on mycotoxin risk. The ranking of oat varieties according to HT2 + T2 levels corresponded with the ranking according to the DNA levels of Fusarium langsethiae, but differed from the ranking according to DON and Fusarium graminearum DNA. Separate tests are therefore necessary to determine the resistance towards HT2 + T2 and DON producers in oats. This creates practical challenges for the screening of FHB resistance in oats as today’s screening focuses on resistance to F. graminearum and DON. We identified oat varieties with generally low levels of both mycotoxins and FHB pathogens which should be preferred to mitigate mycotoxin risk in Norwegian oats.

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Sammendrag

Despite substantial efforts to control locusts they remain periodically a major burden in Africa, causing severe yield loss and hence loss of food and income. Distribution maps indicating the value of the basic reproduction number R0 was used to identify areas where an insect pest can be controlled by a natural enemy. A dynamic process-based mathematical model integrating essential features of a natural enemy and its interaction with the pest is used to generate R0 risk maps for insect pest outbreaks, using desert locust and the entomopathogenic fungus Metarhizium acridum (Synn. Metarhizium anisoliae var. acridum) as a case study. This approach provides a tool for evaluating the impact of climatic variables such as temperature and relative humidity and mapping spatial variability on the efficacy of M. acridum as a biocontrol agent against desert locust invasion in Africa. Applications of M. acridum against desert locust in a few selected African countries including Morocco, Kenya, Mali, and Mauritania through monthly spatial projection of R0 maps for the prevailing climatic condition are illustrated. By combining mathematical modeling with a geographic information system in a spatiotemporal projection as we do in this study, the field implementation of microbial control against locust in an integrated pest management system may be improved. Finally, the practical utility of this model provides insights that may improve the timing of pesticide application in a selected area where efficacy is highly expected.