Somatiska embryogenes är en mikroförökningsmetod som med hjälp av tillväxtreglerande medel får en växtdel att bilda skott och rötter i ett speciellt odlingssubstrat sterila förhållanden. Kunskapen vad gäller förutsättningar för groning och plantetablering efter detta laboratoriestudium är dock begränsad. I denna studie undersökte hur två kloner av SE-groddar av gran etablerade sig i olika ljusförhållanden avseende våglängd och intensitet i fyra växtmiljöer. Etableringen bedömdes utifrån plantornas överlevnad och höjdtillväxt. Vid sista inventeringstillfället var 62 SE-plantor vid liv och 18 plantor var döda. Ingen signifikant skillnad kunde påvisas i överlevnad mellan de olika växtmiljöerna, inte heller mellan klonerna i respektive miljö eller oberoende av miljö. Signifikant skillnad i höjdtillväxten mellan klonerna kunde påvisas inom alla växtmiljöer, men inte mellan växtmiljöerna oberoende av klon. Det fanns en tendens att ljusförhållanden med en ljusintensitet på 100 μmol och rött ljus inom våglängderna 610-760 nm gav bäst etablering för SE-groddarna. Studien visade också att det var skillnad i etablering mellan de två kloner som användes.

The aim of this work was to develop a production process for the enzyme xyloglucan endo-transglycosylase from Populus tremula x tremuloides (PttXET16-34). The natural transglycosylating activity of this enzyme has previously been employed in a XET-Technology. This chemo enzymatic method is useful for biomimetic modification of cellulose surfaces and holds great potential for industrial applications. Thus, it requires that the XET-enzyme can be produced in larger scale. This work also shows how the wildtype PttXET16-34 was modified into a glycosynthase. By mutation of the catalytic nucleophile into an alanine, glycine or serine residue, enzymes capable of synthesising defined xyloglucan fragments were obtained. These defined compounds are very valuable for further detailed studies of xyloglucan active-enzymes, but are also useful in molecular studies of the structurally important xyloglucan-cellulose interaction. A heterologous production system for PttXET16-34 was previously developed in the methylotrophic yeast Pichia pastoris. A methanol-limited fed-batch process was also previously established, but the yield of active XET was low due to proteolysis problems and low productivity. Therefore, two alternative fed-batch techniques were investigated for the production of PttXET16-34: a temperature-limited fed-batch (TLFB) and an oxygen-limited high-pressure fed-batch (OLHPFB). For the initial recovery of XET after the fermentation process, two different downstream processes were investigated: expanded bed adsorption (EBA) and cross-flow filtration (CFF). / <p>QC 20101108</p>

UDP-sugar metabolizing pyrophosphorylases provide the primary mechanism for de novo synthesis of UDP-sugars, which can then be used for myriads of glycosyltranferase reactions, producing cell wall carbohydrates, sucrose, glycoproteins and glycolipids, as well as many other glycosylated compounds. The pyrophosphorylases can be divided into three families: UDP-Glc pyrophosphorylase (UGPase), UDP-sugar pyrophosphorylase (USPase) and UDP-N-acety lglucosamine pyrophosphorylase (UAGPase), which can be discriminated both by differences in accepted substrate range and amino acid sequences. This thesis focuses both on experimental examination (and re-examination) of some enzymatic/ biochemical properties of selected members of the UGPases and USPases and UAGPase families and on the design and implementation of a strategy to study in vivo roles of these pyrophosphorylases using specific inhibitors. In the first part, substrate specificities of members of the Arabidopsis UGPase, USPase and UAGPase families were comprehensively surveyed and kinetically analyzed, with barley UGPase also further studied with regard to itspH dependency, regulation by oligomerization, etc. Whereas all the enzymes preferentially used UTP as nucleotide donor, they differed in their specificity for sugar-1-P. UGPases had high activity with D-Glc-1-P, but could also react with Frc-1-P, whereas USPase reacted with arange of sugar-1-phosphates, including D-Glc-1-P, D-Gal-1-P, D-GalA-1-P, β-L-Ara-1-P and α-D-Fuc-1-P. In contrast, UAGPase2 reacted only with D-GlcNAc-1-P, D-GalNAc-1-P and, to some extent, with D-Glc-1-P. A structure activity relationship was established to connect enzyme activity, the examined sugar-1-phosphates and the three pyrophosphorylases. The UGPase/USPase/UAGPase active sites were subsequently compared in an attempt to identify amino acids which may contribute to the experimentally determined differences in substrate specificities. The second part of the thesis deals with identification and characterization of inhibitors of the pyrophosphorylases and with studies on in vivo effects of those inhibitors in Arabidopsis-based systems. A novel luminescence-based high-throughput assay system was designed, which allowed for quantitative measurement of UGPase and USPase activities, down to a pmol per min level. The assay was then used to screen a chemical library (which contained 17,500 potential inhibitors) to identify several compounds affecting UGPase and USPase. Hit-optimization on one of the compounds revealed even stronger inhibitors of UGPase and USPase which also strongly inhibited Arabidopsis pollen germination, by disturbing UDP-sugar metabolism. The inhibitors may represent useful tools to study in vivo roles of the pyrophosphorylases, as a complement to previous genetics-based studies. The thesis also includes two review papers on mechanisms of synthesis of NDP-sugars. The first review covered the characterization of USPase from both prokaryotic and eukaryotic organisms, whereas the second review was a comprehensive survey of NDP-sugar producing enzymes (not only UDP-sugar producing and not only pyrophosphorylases). All these enzymes were discussed with respect to their substrate specificities and structural features (if known) and their proposed in vivo functions.

During the COVID pandemic of 2019, Sweden saw a huge increase in food prices, as many of the country's grocery chains import a large amount of all foods. This research is motivated by the Swedish Parliament's motion "Self-Sufficiency of Food in Sweden" and the need for innovative solutions to enhance Sweden's food supply. This study focuses on alternative urban agriculture methods, with a focus on aeroponics, aquaponics, hydroponics, and vertical farming, and their potential for self-sufficiency in Sweden. This study aims to fill the gap in Swedish research on soilless urban farming methods and contribute to the understanding and acceptance of the alternative methods above. The study seeks to determine whether the yield of alternative cultivation methods is comparable to traditional methods, soil-based and greenhouse-based farming, in terms of resources invested and to identify the alternative method with the highest yield. Resources in this thesis will be defined as the amount of water that is used. Our thesis aims to support businesses and local governance in decision-making regarding implementation of alternative urban farming in Sweden. A literature search was conducted using keywords such as hydroponic, vertical farming and sustainability. Statistical analysis of collected data indicates significant differences in yield and water usage among the collected examples which resulted in vertical hydroponic farming offering the highest yield in terms of space utilization, with significant statistical significance (p &lt; 0.05). Additionally, hydroponic farming requires the least amount of water compared to other methods although this is not a certainty as there was no significant statistical difference between the different methods. The study demonstrates that hydroponic farming can achieve higher yields compared to traditional soil-based farming and other alternative farming methods. The study emphasizes organizational and governmental solutions to improve self-sufficiency at the local and national levels. Alternative urban farming methods offer a sustainable contribution to increasing self-sufficiency while minimizing resource usage. / Denna studie undersöker potentialen hos alternativa urbana odlingsmetoder för självförsörjning i Sverige. Den svenska riksdagen stödjer motion om "Självförsörjning av mat i Sverige" och behovet av innovativa lösningar för matförsörjning i landet. Denna forskning fyller en kunskapsbrist i den svenska litteraturen om jordlösa odlingssystem såsom aeroponiska, akvaponiska, hydroponiska och vertikala odlingar. Syftet med studien är att sammanfatta den befintliga kunskapen om dessa alternativa odlingsmetoder och klargöra deras fördelar i en urban miljö. Denna studie strävar att stödja företag och lokala myndigheter vid implementering av alternativa odlingsmetoder, genom att studera de alternativa odlingsmetodernas avkastning i förhållande till resursanvändning. Studien har samlat exempel från forskningsartiklar och företags-hemsidor som använde de ovan nämnda alternativa odlingsmetoder som sedan analyserats och jämfört deras avkastning med traditionella jordbaserade odlingar såsom åker odlingar och växthusbaserade odlingar. Med den statistisk analys som gjorts har vi funnit att vertikal hydroponisk odling visar den högsta avkastningen per yta jämfört med de andra alternativa odlingsmetoderna och traditionella odlingar. Vi har dessutom fastställt att hydroponiska odlingar använder minst vatten per kg skörd i jämförelse med andra metoder. Studien betonar vikten av att fokusera på organisatoriska och statliga lösningar för att öka självförsörjningsgraden på lokal och nationell nivå. Medan privatpersoner kan vara självförsörjande med grönsaker och frukt på en normalstor tomt, kan det vara svårt för alla privatpersoner att upprätthålla en egen grönsaksträdgård och undvika skador på marken och ekosystemtjänsterna i staden. Därmed riktar vi denna studie till kommunen och staten som ett stöd för att säkerställa självförsörjning på en lokal och regional nivå. För att uppnå hållbar samhällsutveckling och stödja självförsörjning av mat i Sverige, är integreringen av alternativa urbana odlingsmetoder på lokal, regional och nationell nivå ett innovativt steg framåt. Metoderna nämnda i denna rapport erbjuder fördelar såsom effektiv minskad vatten- och markanvändning samt möjlighet att integrera odling i stadsområden. Genom att använda dessa odlingsmetoder kan Sverige öka sin självförsörjningsgrad och minska sin miljöpåverkan från livsmedelsproduktionen. Framtida forskning bör utforska och utveckla dessa innovativa lösningar för att möta Sveriges matförsörjnings- och hållbarhetsmål.