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.
2010
Sammendrag
The production of hydrogen in green algae is catalyzed by FeFe- hydrogenases, which have high conversion efficiency and high oxygen sensitivity. Most green algae analyzed to date where hydrogenase genes are detected, have been shown to contain two distinct hydrogenases. However, very little is known about which functions the two different enzymes represent. There are also many unknowns within the mechanisms behind hydrogen production as to the roles hydrogenases play under different conditions, and consequently also about the potential for optimization of a hydrogen production process which could be found in this respect. The presented study focuses on the possibility for presence of more than two hydrogenases in a single green alga. A large number of degenerate primers were designed and used to produce 3"-RACE products, which in turn were used to design gene specific primers used for PCR and 5"-RACE reactions. The sequences were aligned with known algal hydrogenases to identify products which had homology to these. Products where homology was identified were then explored further. A high number of clones from each band were sequenced to identify products with similar lengths which would not show up as separate bands on a gel. Sequences found to have homology with algal hydrogenases were translated into putative amino acid sequences and analyzed further to obtain detailed information about the presence of specific amino acids with known functions in the enzyme. This information was used to evaluate the likelihood of these transcripts coding for true hydrogenases, versus hydrogenase-like or narf-like proteins. Conclusion: Evidence showing that Chlamydomonas noctigama is able to transcribe three genes which share a significant number of characteristics with other known algal FeFe-hydrogenases is presented . The three genes have been annotated hydA1, hydA2 and hydA3.
Forfattere
Alexander Engebretsen Sigrun KværnøSammendrag
Rapporten presenterer kartlagt fosforstatus i jord i Vannområde Morsa i Akershus/Østfold. Vansjø-Hobølvassdraget med delfelter og Kystbekker Morsa med delområder er behandlet hver for seg. Kart og statistiske analyser er basert på P-AL-verdi i jordprøver tatt ut i perioden 1990 - 2008. Mesteparten av dataene i Vansjø-Hobølvassdraget er samlet inn av landbrukskontorene i Morsa-kommunene, mens noen data kommer fra Jorddatabanken ved Bioforsk. Alle data for Kystbekker Morsa kommer fra Jorddatabanken. Jordprøvene er etter beste evne forsøkt stedfestet, i det minste ned på gårds- og bruksnummernivå. Fosforkart (kart over P-AL i jord) er laget for hvert delfelt, i Vansjø-Hobølvassdraget ved spline-interpolering mellom prøvepunkter, og i Kystbekker Morsa ved å knytte P-AL verdier til eiendomskart. Prosentvis dekningsgrad av jordprøvetaking var 76 % i Vansjø-Hobølvassdraget og 65 % i Kystbekker Morsa. Variasjonsområdet for de ulike delfeltene var 50 til 93 % dekningsgrad. Arealmessig manglet det mest data i delfeltene Hobølelva (ca 11 000 daa) i Vansjø-Hobølvassdraget og Rygge (ca 7000 daa) i Kystbekker Morsa. Jordprøvene som de statistiske analysene og kartene var basert på, var hovedsakelig fra 2000-tallet, men bare 39 % var fra 2005 eller senere i Vansjø-Hobølvassdraget og tilsvarende bare 20 % i Kystbekker Morsa. P-AL i jord varierte mellom 1 og 72 mg/100 g i enkeltprøver, med en middelverdi på 10 mg/100 g for Vansjø-Hobølvassdraget (P-AL-klasse "middels til høyt" eller 8-10 mg/100 g) og 18 mg/100 g for Kystbekker Morsa ("meget høyt" eller 15-20 mg/100 g). Delfeltene hadde middelverdier mellom 8 og 19 mg/100 g, lavest i nordlige og midtre del av Vansjø-Hobølvassdraget, og høyest rundt Vansjø og særlig i kystbekkfeltene. De tre øverste P-AL-klassene (≥ 11 mg/100 g), som motsvarer ingen P-gjødsling, utgjorde 33 % i Vansjø-Hobølvassdraget og 81 % i Kystbekker Morsa. Av alle felter utmerket kystbekkfeltet Rygge seg med høyest P-AL-tall, i middel 19 mg/100 g, og 92 % i de tre øverste P-AL-klassene. Her lå hele 34 % i klassen "særdeles høyt", som betyr P-AL > 20 mg/100 g.
Sammendrag
Understanding the feedback between terrestrial biosphere processes and meteorological drivers is crucial to ecosystem research as well as management. For example, remote sensing of the activity of vegetation in relation to environmental conditions provides an invaluable basis for investigating the spatiotemporal dynamics and patterns of variability. We investigate the Fraction of Absorbed Photosynthetically Active Radiation (fAPAR) using SeaWiFS satellite observations from 1998 to 2005 and ancillary meteorological variables from the CRU-PIK dataset. To what extent do precipitation and temperature dominate the terrestrial photosynthetic activity on monthly to interannual time scales? A spectral decomposition using Singular System Analysis leads to a global ‘classification’ of the terrestrial biosphere according to prevalent time-scale dependent dynamics of fAPAR and its relation to the meteorology. A complexity analysis and a combined subsignal extraction and dimensionality reduction reveals a series of dominant geographical gradients, separately for different time scales. Here, we differentiate between three time scales: on short time scales (compared to the annual cycle), variations in fAPAR coincide with corresponding precipitation dynamics. At the annual scale, which explains around 50% of the fAPAR variability as a global average, patterns largely resemble the biomes of the world as mapped by biogeographic methods.At longer time scales, spatially coherent patterns emerge which are induced by precipitation and temperature fluctuations combined. However, we can also identify regions where the variability of fAPAR on specific time scales cannot be traced back to climate and is apparently shaped by other geoecological or anthropogenic drivers. http://uregina.ca/prairies/assets/Prairie_Summit_Final_Program.pdf
Sammendrag
Determining the feedbacks between terrestrial biosphere processes and the meteorological drivers (here precipitation and temperature) is crucial to ecosystem research. In this context, the continuous monitoring of the earth surface provides an invaluable basis for investigating the spatiotemporal dynamics in the activity of vegetation in relation to environmental conditions. Here, we seek to identify which patterns of variability in the meteorological drivers dominate the terrestrial photosynthetic activity from monthly to interannual time scales (resp. fluctuation frequencies). We investigate the Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) using SeaWiFS observations from 1998 to 2005 and ancillary meteorological variables. A spectralanalysis leads to a global `classification` of the terrestrial biosphere according to prevalent scale dependent dynamics of fAPAR and its relation to the meteorology. A combined subsignal extraction and dimensionality reduction reveals a series of dominant geographical gradients on specific time scales. E.g. we uncover spatially coherent patterns at low frequencies and show where these are induced by precipitation or temperature fluctuations. We also show where high frequency variations (relative to the annual cycle) in fAPAR coincide with corresponding precipitation dynamics. However, we can also identify regions where the variability of fAPAR on specific time scales cannot be traced back to climate and is apparently shaped by other geoecological or anthropogenic drivers. http://www.terrabites.net/fileadmin/user_upload/terrabites/PDFs/Programme_Book_TERRABITES.pdf
Sammendrag
Green algae are known to produce H2 under sulphur deprivation in a process called biophotolysis, where solar energy is used to split water and generate O2 and H2. There is still considerable potential for improvement and very little is known about how this mechanism varies between species. This is part of Bioforsk research activities linked to green algae and H2 production. In order to make a H2 production process from algae economically viable, we face several challenges, including bioreactor design, optimisation of environmental conditions, efficiency improvement by genetic and metabolic engineering. One possibility for improving the economical potential of a hydrogen production process also includes exploitation of the algal biomass which, as a result of stress reactions, may produce metabolites with pharmaceutical value. Joining forces with The Norwegian University of Life Science (UMB) and The Norwegian Forest and Landscape Institute, Bioforsk has established The Norwegian Centre for Bioenergy Research. Bioforsk has also taken a leading role on biogas in the newly established CenBio - a national Centre for Environmental- friendly Energy Research. The modern biogas laboratories are located close to facilities for plant growth studies, making them easy accessible for experimental studies of the entire chain from biomass to fertiliser. Research activities include innovative pre-treatment of substrates for increased biogas yield, effects of substrate mixtures for biogas production and digestate quality, biogas potential and biogas process studies, digestates as fertiliser, and effects on the environment and climate
Forfattere
Kari SkjånesSammendrag
Det er ikke registrert sammendrag
Forfattere
Lars Bakken Tore Krogstad Anne Kjersti Uhlen Nils Bjugstad Anne Kjersti Bakken Arne Grønlund Atle Hauge Bernt Hoel Audun Korsæth Hugh Riley Hans Christian Endrerud Kjell MangerudSammendrag
Denne rapporten er en utredning av kompetansegrunnlaget for bedre agronomi for å møte landbrukets klimautfordringer. Utredningen er gjort på oppdrag for Norges forskningsråd av Bioforsk, UMB og Høyskolen i Hedmark. Utredningen omhandler hvilke agronomiske muligheter og utfordringer jordbruket står overfor for å nå målene om lavere utslipp av klimagasser. Den tar også opp agronomiske utfordringer knyttet til effekter av endret klima og jordbrukets tilpasningsmulighter og behov for tiltak. Den gir en oversikt over hvor det er behov for målrettet FoU-innsats, og kommer med forslag til hvordan man kan sikre et godt utdanningstilbud og forskerrekruttering innen land-bruksteknikk og andre viktige områder av agronomien der studenttilgangen nå er for lav. Se utvidet sammendrag.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Ketil HaarstadSammendrag
A literature review shows that more than 500 organic and metallic compounds have been reported occurring in wetlands, and also that wetlands are suitable for removing pollutants. There are, however, obvious pitfalls for treatment wetlands, the most important being the maintenance of the hydraulic capacity and controlling the detention time. Treatment wetlands should have an adapted design to target specific compounds. Aquatic plants and soils are suitable for wastewater treatment because they have a high capacity of removing nutrients and other substances through uptake, sorption and microbiological degradation. The heavy metals Cd, Cu, Fe, Ni and Pb were found to exceed limit values in water. Also these studies revealed high values of phenol and SO4. No samples showed concentrations in sediments exceeding limit values, but fish samples showed concentrations of Hg exceeding the limit for fish sold in the EU. The main route of heavy metal uptake in aquatic plants was through the roots in the case of emergent and surface floating plants, whereas in submerged plants roots as well as leaves take part in removing heavy metals and nutrients. Submerged rooted plants have potential from water as well as sediments, where as rootless plants extracted metals rapidly only from water. Caution is due about the use of SSF CWs for the treatment of metal-contaminated industrial wastewater as metals are shifted to another environmental compartment and moreover stable redox conditions are required to ensure long-term efficiency. Mercury is one of the most toxic heavy metals and since wetlands have been shown to be a source of methylmercury. Methyl Hg concentrations are typically approximately 15% of Hgt. In wetland water samples, PAH, bisphenol A, BTEX, hydrocarbons including diesel range organics, glycol, DDT, PCB, cyanide, benzene, chlorophenols and formaldehyde were found to exceed limit values. In sediments only PAH and PCB were found exceeding limit values. In the water phase the pesticides found above limit values were atrazine, simazine, terbutylazine, metolachlor, mecoprop, endosulfan, chlorfenvinphos and diuron. There are few listings of these compounds in the commonly used water quality limit values, except for some well-known endocrine disrupters such as nonylphenol, phtalates etc. The performance of extensive household wastewater treatment systems of removing pharmaceuticals and personal care products (PPCPs) are similar to that obtained in conventional activated sludge wastewater treatment plants
Forfattere
Kari SkjånesSammendrag
Green microalgae can be used for a number of commercial applications, including health food for human consumption, aquaculture and animal feed, coloring agents, cosmetics and pharmaceuticals. Several products from green algae that are in use today, consist of metabolites which can be extracted from the algal biomass. The most well known examples are the carotenoids astaxanthin and Β-carotene, which are used as coloring agents and for health promoting purposes. Many species of green algae are able to produce valuable components for different uses, examples are antioxidants, several different carotenoids, polyunsaturated fatty acids, vitamins, anticancer and antiviral drugs. In many cases these components are secondary metabolites which are produced when the algae are exposed for stress conditions like for example nutrient deprivation, light intensity, temperature, salinity, pH and other. In other cases the components have been detected in algae grown under optimal conditions, and little is known about how an optimal production of each product could be induced and how their production would react to stress conditions. Some green algae have shown the ability to produce significant amounts of hydrogen gas during sulfur deprivation, a process which is currently extensively studied. At the moment, the majority of research in this field has focused on the model organism Chlamydomonas reinhardtii, but other species of green algae have also showed this ability. Currently there is scarce information available regarding the possibility for producing hydrogen and other valuable components in the same process. This study explores stress conditions which are known to induce production of the different valuable products in comparison with stress reactions leading to hydrogen production. Wild type species of green microalgae with ability to produce hydrogen during anaerobic conditions, and during sulfur deprivation are compared to species with known ability to produce high amounts of certain valuable metabolites. . This information is explored in order to form a basis for selection of wild type species for a future multidiciplinary process, where hydrogen production from solar energy is combined with production of valuable metabolites and other commercial uses of the algal biomass.