Nitrogen (N) deposition has increased globally over the last 150 years and further increase is predicted for the future. Nitrogen is an important nutrient for lichens, involved in many processes in both photobiont and mycobiont.  However, N can be a stressor, causing many lichens and lichen communities to disappear with increased deposition. The objective of this thesis was to investigate the response of epiphytic lichens to increased N load. This was done by simulating an increased N deposition to lichens in a boreal forest with low background N, including both short term studies with transplanted lichens and long term studies of naturally established lichens. Alectoria sarmentosa was used as a model species for a N-sensitive lichens and Platismatia glauca as a relatively more N-tolerant lichen. Nitrogen deposition was simulated by daily spraying during the growing season with water and isotopically labeled ammonium nitrate (NH4NO3). In Paper I, I found that when N is supplied in realistic doses (equivalent to deposition of 0.6, 6, 12.5, 25 and 50 kg N ha-1), there were no significant differences in uptake of NO3- or NH4+ in either of the lichen species. The results in Paper II indicate that A. samentosa may be limited by phosphorous (P) and not N limited as expected. That study highlights the importance of P, when studying the effects of N deposition, since P can both mitigate and intensify the negative effects of N on epiphytic lichens. Paper III shows that four years of simulated N deposition caused an alteration of the epiphytic lichen community, since A. sarmentosa decreased in the highest N loads (25 and 50 kg ha-1 year-1), Bryoria spp. decreased to 12.5 kg N and higher loads and Hypogymnia physodes decreased over time for all treatments except in 12.5 kg ha-1, where it only decreased during the first treatment year and then increased after 2007.  The abundance of Platismatia glauca increased over time, independent of treatment. As hypothesized, responses to the treatments differed among species, reflecting their different N optima. In paper IV, the effects of N on carbon-based secondary compounds were studied. None of the studied species (P. glauca, A. sarmentosa, Lobaria scrobiculata and Xanthoria aureola) reduced their concentration of secondary compounds during the experimental period, but in P. glauca the concentration of all compounds were significantly lower in N treated thalli compared with control thalli. The results are consistent with a high degree of constitutive defence in three of the four studied lichens, and we conclude that all four studied lichens seem to have a robust chemical defence system despite considerable manipulation of the environmental conditions. However, we don't know if these lichens are able to keep up the high protection level over longer periods comprising a number of years when more new tissue is formed. In conclusion, long term experiments are necessary to understand lichen response to environmental changes.

Som följd av dagens ökning i global befolkning och köttproduktion är alternativa hållbara köttsubstitut mycket eftertraktat. Som basal råvara kan växter eller mikrobiella produkter utnyttjas för proteinrika hållbara livsmedelsprodukter. Detta arbete syftar till att undersöka olika proteinextraktionsmetoder som i nuläget används för att erhålla ett proteinisolat som kan ha användning i livsmedelsindustrin. Utvalda råvaror som kommer studeras och diskuteras är ärta, quinoa, mjölmask och filamentösa svampar. Allmän information för varje råvara diskuteras men fokus har lagts på att studera processer för att extrahera proteiner till ett isolat från råvarorna. Arbetet inkluderar generella tillvägagångssätt vad gäller proteinextraktion likväl som mer specifika metoder från enskilda försök att extrahera ett visst protein. Slutligen jämförs val av extraktionsmetoder och vilka råvaror som idag är i kommersiellt bruk och reflekterande tankar om varför inte vissa råvaror hunnit lika långt i utvecklingen i proteinextraktion som andra. / As a result of today's increase in global population and meat production, alternative and more sustainable meat substitutes are highly sought after. As a basic raw material, plants or microbial products can be utilized for protein-rich sustainable food products. This work aims to investigate various protein extraction methods currently used to obtain a protein isolate that can be of use in the food industry. Selected raw materials studied and discussed are pea, quinoa, flour worm and filamentous fungus. General information for each raw material is discussed, however focus has been on studying processes for extracting proteins into an isolate from the raw materials. The work includes general methods to protein extraction as well as more specific methods from individual attempts to extract a specific protein. Finally, the extraction methods are compared, the raw materials that are currently in commercial use are discussed as well as thoughts why some raw materials have not progressed as far in protein extraction as others are compared.

Grocott metoden är den känsligaste metoden för infärgning av svampstrukturer i histologisk vävnad i jämförelse med till exempel Periodic Acid-Schiff (PAS). Handhavandet av det cancerogena oxidationsmedlet kromsyra samt tidsaspekten för Grocott är signifikanta problem. Syftet med studien var att undersöka om den automatiserade färgningsmetoden för Grocott ger likvärdiga resultat som vid den manuella färgningsmetoden. Tolv preparat färgades med både den manuella och den automatiserade metoden för Grocott. Den automatiserade färgningsmetoden använder ett färdigt kit med alla ingående lösningar. Visuell bedömning av preparaten utfördes med hjälp av legitimerade biomedicinska analytiker samt en patolog. Svampstrukturer i åtta av ela preparat samt kontroll bedömdes vara tydligare infärgade med den automatiserade metoden i färhållande till den manuella. Svampstrukturer i endast ett preparat bedömdes vara tydligare infärgade med den manuella metoden. Resterande två preparat visade inga svampstrukturer. Resultaten tyder på att den automatiserade färgningsmetoden för Grocott ger likvärdiga, alternativt tydligare infrägning av svampstrukturer i jämförelse med den manuella metoden. / The Grocott method is the most sensitive staining method for fungal structures in histological tissues in comparison to for example Periodic Acid-Schiff (PAS). Usage of the cancerogenic chromic acid and the time aspect for Grocott are significant problems. The aim of this study was to examine if the automated staining method for Grocott provides equivalent results in comparison to the manual staining method. Twelve tissue sections were stained with both the automated and the manual method. The automated method contains a kit with all solutions. Visual evaluation was conducted with authorized biomedical scientists and a pathologist. Fungi structures in eight of eleven tissue sections and a control were evaluated as more distinct in the automated method in comparison to the manual method. Fungal structures in one of the tissue sections were evaluated more distinct in the manual method. In the remaining two tissue sections, no fungal structures were identified. Results from this study indicates that the automated staining method for Grocott provides equally, alternatively more distinct fungal staining in comparison to the manual method.