253 research outputs found

    The Development of Cellulosic Fuels

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    Development of feedstocks for cellulosic biofuels

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    The inclusion of cellulosic ethanol in the Energy Independence and Security Act (EISA) of 2007 and the revised Renewable Fuel Standard (RFS2) has spurred development of the first commercial scale cellulosic ethanol biorefineries. These efforts have also revived interest in the development of dedicated energy crops selected for biomass productivity and for properties that facilitate conversion of biomass to liquid fuels. While many aspects of developing these feedstocks are compatible with current agricultural activities, improving biomass productivity may provide opportunities to expand the potential for biofuel production beyond the classical research objectives associated with improving traditional food and feed crops

    FInal Report for Award DE-FG02-06ER64291

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    The original goal of this award was to develop a proteoglycan 'chip' containing suitable oligosaccharides that could be used as substrates for glycosyltransferases involved in synthesis or proteoglycans in higher plant cell walls. We had previously developed a suite of cloned enzymes that could be used to cleave most of the relevant glycosidic linkages in plant cell walls. The next step, supported by the previous award and this award, was to produce a series of transgenic plants in which synthetic proteins were introduced that contained each of the known sequence motifs that induce prolyl hydroxylation, and subsequent glycosylation. This work was completed and published in Estevez et al (2006). We then engaged on a series of experiments to define the properties of the prolyl hydroxylases that convert certain prolyl resides to hydroxyproline for subsequent glycosylation. This proved to be a challenging goal that required recruitment of an international team of complementary skills and several additional years of research. However, the effort was successful and has been published in Science recently (Velasquez et al., 2011). In the course of this project, the postdoc supported by the award (Jose Estevez) was asked to provide technical assistance to a colleague at Stanford because of his expertise in marine polysaccharides. This led to the important discovery that marine algae have compounds that could be classified as lignin (Martone et al., 2009)

    Regulation of membrane fatty acid composition by temperature in mutants of Arabidopsis with alterations in membrane lipid composition

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    BACKGROUND: A wide range of cellular responses occur when plants are exposed to elevated temperature, including adjustments in the unsaturation level of membrane fatty acids. Although membrane bound desaturase enzymes mediate these adjustments, it is unknown how they are regulated to achieve these specific membrane compositions. Furthermore, the precise roles that different membrane fatty acid compositions play in photosynthesis are only beginning to be understood. To explore the regulation of the membrane composition and photosynthetic function in response to temperature, we examined the effect of temperature in a collection of mutants with altered membrane lipid fatty acid composition. RESULTS: In agreement with previous studies in other species, the level of unsaturation of membrane fatty acids in Arabidopsis was inversely correlated with growth temperature. The time required for the membrane fatty acids to attain the composition observed at elevated temperature was consistent with the timing required for the synthesis of new fatty acids. Comparisons of temperature-induced fatty acid alterations in membranes were made among several Arabidopsis lines including wild-type Columbia, and the compositional mutants, fad5, fad6, act1 and double mutants, fad7 fad8 and act1 fad6. The results revealed key changes that occur in response to elevated temperature regardless of the specific mutations in the glycerolipid pathway, including marked decreases in trienoic fatty acids and consistent increases in unsaturated 16:0 and in dienoic 18:2 levels. Fluorescence measurements of various mutants indicated that photosynthetic stability as well as whole plant growth at elevated temperature is influenced by certain membrane fatty acid compositions. CONCLUSIONS: The results of this study support the premise that defined proportions of saturated and unsaturated fatty acids in membrane lipids are required for photosynthetic thermostability and acclimation to elevated temperature. The results also suggest that changes in the membrane fatty acid composition brought about in response to temperature are regulated in such a way so as to achieve highly similar unsaturation levels despite mutations that alter the membrane composition prior to a high-temperature exposure. The results from examination of the mutant lines also suggest that interorganellar transfer of fatty acids are involved in mediating temperature-induced membrane alterations, and reveal steps in the fatty acid unsaturation pathway that appear to have key roles in the acclimatization of membranes to high temperature

    EDR2 negatively regulates salicylic acid-based defenses and cell death during powdery mildew infections of Arabidopsis thaliana

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    <p>Abstract</p> <p>Background</p> <p>The hypersensitive necrosis response (HR) of resistant plants to avirulent pathogens is a form of programmed cell death in which the plant sacrifices a few cells under attack, restricting pathogen growth into adjacent healthy tissues. In spite of the importance of this defense response, relatively little is known about the plant components that execute the cell death program or about its regulation in response to pathogen attack.</p> <p>Results</p> <p>We isolated the <it>edr2-6 </it>mutant, an allele of the previously described <it>edr2 </it>mutants. We found that <it>edr2-6 </it>exhibited an exaggerated chlorosis and necrosis response to attack by three pathogens, two powdery mildew and one downy mildew species, but not in response to abiotic stresses or attack by the bacterial leaf speck pathogen. The chlorosis and necrosis did not spread beyond inoculated sites suggesting that EDR2 limits the initiation of cell death rather than its spread. The pathogen-induced chlorosis and necrosis of <it>edr2-6 </it>was correlated with a stimulation of the salicylic acid defense pathway and was suppressed in mutants deficient in salicylic acid signaling. <it>EDR2 </it>encodes a novel protein with a pleckstrin homology and a StAR transfer (START) domain as well as a plant-specific domain of unknown function, DUF1336. The pleckstrin homology domain binds to phosphatidylinositol-4-phosphate <it>in vitro </it>and an EDR2:HA:GFP protein localizes to endoplasmic reticulum, plasma membrane and endosomes.</p> <p>Conclusion</p> <p><it>EDR2 </it>acts as a negative regulator of cell death, specifically the cell death elicited by pathogen attack and mediated by the salicylic acid defense pathway. Phosphatidylinositol-4-phosphate may have a role in limiting cell death via its effect on EDR2. This role in cell death may be indirect, by helping to target EDR2 to the appropriate membrane, or it may play a more direct role.</p

    Enhancing graduate employability through targeting ePortfolios to employer expectations: A systematic scoping review

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    Electronic portfolios (ePortfolios) are increasingly being used in university degrees to showcase graduate employability. However, evidence on employers’ views and use of ePortfolios has not been synthesised. This study aimed to systematically review the evidence on employer, industry representative and university educator views on the use of ePortfolios in recruiting graduates, including recommended ePortfolio content. Six databases were searched to identify original research on views and utilisation of ePortfolios published since 2000. Studies were screened in duplicate, and the full texts of 163 articles reviewed. Included studies were synthesised to reveal common themes. The 17 included studies represented a range of industries and most were conducted in the USA (n=10). Awareness of ePortfolios was low, as was use within recruitment. Perceived advantages of ePortfolios in recruitment included showcasing key skills/work; ability to comprehensively assess and differentiate between candidates quickly; and accessibility. The main disadvantages were the time taken to review, excessive information and establishing authenticity. Recommended ePortfolios content included samples of professional work, reflections, videos and photos. Inclusion of typical resume content, work experience, skills, transcripts, certificates, references, supervisor evaluations were important, as was a clear and concise structure

    α-Glucosidase I is required for cellulose biosynthesis and morphogenesis in Arabidopsis

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    Novel mutations in the RSW1 and KNOPF genes were identified in a large-scale screen for mutations that affect cell expansion in early Arabidopsis embryos. Embryos from both types of mutants were radially swollen with greatly reduced levels of crystalline cellulose, the principal structural component of the cell wall. Because RSW1 was previously shown to encode a catalytic subunit of cellulose synthase, the similar morphology of knf and rsw1-2 embryos suggests that the radially swollen phenotype of knf mutants is largely due to their cellulose deficiency. Map-based cloning of the KNF gene and enzyme assays of knf embryos demonstrated that KNF encodes α-glucosidase I, the enzyme that catalyzes the first step in N-linked glycan processing. The strongly reduced cellulose content of knf mutants indicates that N-linked glycans are required for cellulose biosynthesis. Because cellulose synthase catalytic subunits do not appear to be N glycosylated, the N-glycan requirement apparently resides in other component(s) of the cellulose synthase machinery. Remarkably, cellular processes other than extracellular matrix biosynthesis and the formation of protein storage vacuoles appear unaffected in knf embryos. Thus in Arabidopsis cells, like yeast, N-glycan trimming is apparently required for the function of only a small subset of N-glycoproteins

    Developing data-driven innovation in creative industries

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    This White Paper reports on the findings of the Data-Driven Innovation (DDI) Programme Sector Development consultation (2018-20), which investigated the data capability and further potential for innovation across the creative industries in the Edinburgh and South East City Region of Scotland. It presents an overview of the findings with early models of delivery through The University of Edinburgh to stimulate greater awareness and support for data innovation ambition, as well as key themes to focus on for future development. Consultation was conducted with the creative industries community in the Edinburgh and South East City Region, including Scottish creative industries trade bodies and networks, leading creative companies and individual creative practitioners, and with staff in The University of Edinburgh. We are grateful to the industry for their feedback, and to colleagues within the Data-Driven Innovation Programme, Edinburgh Futures Institute, Creative Informatics Cluster and their partners Edinburgh Napier University, Codebase and Creative Edinburgh for their input, advice and support. The consultation that informs this White Paper was initiated and supported by the Data-Driven Innovation Programme of The University of Edinburgh within the Edinburgh and South East Region City Deal
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