105 research outputs found

    Commodity Risk Exposure in the Forestry and Paper Industry

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    We aim to investigate the risk exposure against commodity prices in the forestry and paper industry. The intension is also to study the affect that the changes in commodity prices has on a company’s market value

    Characterization of the hupSL promoter activity in Nostoc punctiforme ATCC 29133

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    <p>Abstract</p> <p>Background</p> <p>In cyanobacteria three enzymes are directly involved in the hydrogen metabolism; a nitrogenase that produces molecular hydrogen, H<sub>2</sub>, as a by-product of nitrogen fixation, an uptake hydrogenase that recaptures H<sub>2 </sub>and oxidize it, and a bidirectional hydrogenase that can both oxidize and produce H<sub>2</sub>.<it>Nostoc punctiforme </it>ATCC 29133 is a filamentous dinitrogen fixing cyanobacterium containing a nitrogenase and an uptake hydrogenase but no bidirectional hydrogenase. Generally, little is known about the transcriptional regulation of the cyanobacterial uptake hydrogenases. In this study gel shift assays showed that NtcA has a specific affinity to a region of the <it>hupSL </it>promoter containing a predicted NtcA binding site. The predicted NtcA binding site is centred at 258.5 bp upstream the transcription start point (tsp). To further investigate the <it>hupSL </it>promoter, truncated versions of the <it>hupSL </it>promoter were fused to either <it>gfp </it>or <it>luxAB</it>, encoding the reporter proteins Green Fluorescent Protein and Luciferase, respectively.</p> <p>Results</p> <p>Interestingly, all <it>hupsSL </it>promoter deletion constructs showed heterocyst specific expression. Unexpectedly the shortest promoter fragment, a fragment covering 57 bp upstream and 258 bp downstream the tsp, exhibited the highest promoter activity. Deletion of the NtcA binding site neither affected the expression to any larger extent nor the heterocyst specificity.</p> <p>Conclusion</p> <p>Obtained data suggest that the <it>hupSL </it>promoter in <it>N. punctiforme </it>is not strictly dependent on the upstream NtcA cis element and that the shortest promoter fragment (-57 to tsp) is enough for a high and heterocyst specific expression of <it>hupSL</it>. This is highly interesting because it indicates that the information that determines heterocyst specific gene expression might be confined to this short sequence or in the downstream untranslated leader sequence.</p

    Metabolic engineering of <i>Synechocystis </i>sp. PCC 6803 for production of the plant diterpenoid manoyl oxide

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    [Image: see text] Forskolin is a high value diterpenoid with a broad range of pharmaceutical applications, naturally found in root bark of the plant Coleus forskohlii. Because of its complex molecular structure, chemical synthesis of forskolin is not commercially attractive. Hence, the labor and resource intensive extraction and purification from C. forskohlii plants remains the current source of the compound. We have engineered the unicellular cyanobacterium Synechocystis sp. PCC 6803 to produce the forskolin precursor 13R-manoyl oxide (13R-MO), paving the way for light driven biotechnological production of this high value compound. In the course of this work, a new series of integrative vectors for use in Synechocystis was developed and used to create stable lines expressing chromosomally integrated CfTPS2 and CfTPS3, the enzymes responsible for the formation of 13R-MO in C. forskohlii. The engineered strains yielded production titers of up to 0.24 mg g(–1) DCW 13R-MO. To increase the yield, 13R-MO producing strains were further engineered by introduction of selected enzymes from C. forskohlii, improving the titer to 0.45 mg g(–1) DCW. This work forms a basis for further development of production of complex plant diterpenoids in cyanobacteria

    Prövad eller beprövad?

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    The rationale for this study stems from the Swedish educational context, where teacher practice is subject to policies stating that education must be built on research foundation and proven experience. In a previous article (Åman & Kroksmark, 2018), we demonstrated that the research foundation is operating in concurrence of teachers’ practices and experiences. This study in turn aims to explore how teachers understand proven experience and practices of proving professional experiences. The data was collected in 2014 in the project Modellskolan [The Model School], financed by the Swedish Research Council, through a stimulated recall method. We filmed 14 interviews with teachers focusing on group discussions about teachers’ practical dilemmas. The interviews were analyzed with a phenomenographic method, and the result revealed five categories with which the teachers evaluated collegial and individual experiences. The categories were analysed through praxis theory and linked to the phenomenological concepts of time and space to elucidate how fluid situated and unspoken professional experiences become systematic, general and partly transferable through proving practices. The results shed light on how teachers’ experiences and everyday practices challenge and encourage revisions of the definitions of research foundation and proven experiencea in Swedish national policies

    Application of nanodisc technology for direct electrochemical investigation of plant cytochrome P450s and their NADPH P450 oxidoreductase

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    Direct electrochemistry of cytochrome P450 containing systems has primarily focused on investigating enzymes from microbes and animals for bio-sensing applications. Plant P450s receive electrons from NADPH P450 oxidoreductase (POR) to orchestrate the bio-synthesis of a plethora of commercially valuable compounds. In this report, full length CYP79A1, CYP71E1 and POR of the dhurrin pathway in Sorghum bicolor were reconstituted individually in nanoscale lipid patches, “nanodiscs”, and directly immobilized on unmodified gold electrodes. Cyclic voltammograms of CYP79A1 and CYP71E1 revealed reversible redox peaks with average midpoint potentials of 80 ± 5 mV and 72 ± 5 mV vs. Ag/AgCl, respectively. POR yielded two pairs of redox peaks with midpoint potentials of 90 ± 5 mV and −300 ± 10 mV, respectively. The average heterogeneous electron transfer rate constant was calculated to be ~1.5 s(−1). POR was electro-catalytically active while the P450s generated hydrogen peroxide (H(2)O(2)). These nanodisc-based investigations lay the prospects and guidelines for construction of a simplified platform to perform mediator-free, direct electrochemistry of non-engineered cytochromes P450 under native-like conditions. It is also a prelude for driving plant P450 systems electronically for simplified and cost-effective screening of potential substrates/inhibitors and fabrication of nano-bioreactors for synthesis of high value natural products

    Shewanella oneidensis: a new and efficient System for Expression and Maturation of heterologous [Fe-Fe] Hydrogenase from Chlamydomonas reinhardtii

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    <p>Abstract</p> <p>Background</p> <p>The eukaryotic green alga, <it>Chlamydomonas reinhardtii</it>, produces H<sub>2</sub> under anaerobic conditions, in a reaction catalysed by a [Fe-Fe] hydrogenase HydA1. For further biochemical and biophysical studies a suitable expression system of this enzyme should be found to overcome its weak expression in the host organism. Two heterologous expression systems used up to now have several advantages. However they are not free from some drawbacks. In this work we use bacterium <it>Shewanella oneidensis</it> as a new and efficient system for expression and maturation of HydA1 from <it>Chlamydomonas reinhardtii</it>.</p> <p>Results</p> <p>Based on codon usage bias and hydrogenase maturation ability, the bacterium <it>S. oneidensis</it>, which possesses putative [Fe-Fe] and [Ni-Fe] hydrogenase operons, was selected as the best potential host for <it>C. reinhardtii </it>[Fe-Fe] hydrogenase expression. Hydrogen formation by <it>S. oneidensis </it>strain AS52 (Δ<it>hydA</it>Δ<it>hyaB</it>) transformed with a plasmid bearing <it>Cr</it>HydA1 and grown in the presence of six different substrates for anaerobic respiration was determined. A significant increase in hydrogen evolution was observed for cells grown in the presence of trimethylamine oxide, dimethylsulfoxide and disodium thiosulfate, showing that the system of <it>S. oneidensis </it>is efficient for heterologous expression of algal [Fe-Fe] hydrogenase.</p> <p>Conclusion</p> <p>In the present work a new efficient system for heterologous expression and maturation of <it>C. reinhardtii </it>hydrogenase has been developed. HydA1 of <it>C. reinhardtii </it>was purified and shown to contain 6 Fe atoms/molecule of protein, as expected. Using DMSO, TMAO or thiosulfate as substrates for anaerobic respiration during the cell growth, 0.4 – 0.5 mg l<sup>-1</sup>(OD<sub>600 </sub>= 1) of catalytically active HydA1 was obtained with hydrogen evolution rate of ~700 μmol H<sub>2 </sub>mg<sup>-1 </sup>min<sup>-1</sup>.</p

    Changes in concentrations of haemostatic and inflammatory biomarkers in synovial fluid after intra-articular injection of lipopolysaccharide in horses

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    Abstract Background Septic arthritis is a common and potentially devastating disease characterized by severe intra-articular (IA) inflammation and fibrin deposition. Research into equine joint pathologies has focused on inflammation, but recent research in humans suggests that both haemostatic and inflammatory pathways are activated in the joint compartment in arthritic conditions. The aim of this study was to characterize the IA haemostatic and inflammatory responses in horses with experimental lipopolysaccharide (LPS)-induced joint inflammation. Inflammation was induced by IA injection of LPS into one antebrachiocarpal joint of six horses. Horses were evaluated clinically with subjective grading of lameness, and blood and synovial fluid (SF) samples were collected at post injection hours (PIH) -120, −96, −24, 0, 2, 4, 8, 16, 24, 36, 48, 72 and 144. Total protein (TP), white blood cell counts (WBC), serum amyloid A (SAA), haptoglobin, iron, fibrinogen, thrombin-antithrombin (TAT) and d-dimer concentrations were assessed in blood and SF. Results Intra-articular injection of LPS caused local and systemic signs of inflammation including increased rectal temperature, lameness and increased joint circumference and skin temperature. Most of the biomarkers (TP, WBC, haptoglobin, fibrinogen and TAT) measured in SF increased quickly after LPS injection (at PIH 2–4), whereas SAA and d-dimer levels increased more slowly (at PIH 16 and 144, respectively). SF iron concentrations did not change statistically significantly. Blood WBC, SAA, haptoglobin and fibrinogen increased and iron decreased significantly in response to the IA LPS injection, while TAT and d-dimer concentrations did not change. Repeated pre-injection arthrocenteses caused significant changes in SF concentrations of TP, WBC and haptoglobin. Conclusion Similar to inflammatory joint disease in humans, joint inflammation in horses was accompanied by an IA haemostatic response with changes in fibrinogen, TAT and d-dimer concentrations. Inflammatory and haemostatic responses were induced simultaneously and may likely interact. Further studies of interactions between the two responses are needed for a better understanding of pathogenesis of joint disease in horses. Knowledge of effects of repeated arthrocenteses on levels of SF biomarkers may be of value when markers are used for diagnostic purposes

    Kalankasvatuksen olosuhdekatsaus 2020

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    Kalankasvatuksen olosuhdekatsauksen laatiminen on osittain rahoitettu Euroopan meri-ja kalatalousrahaston (EMKR) avustuksella. Katsaus tuottaa tietoa EMKR:n Suomen toimintaohjelman arviointia ja ennakointia varten

    Photoautotrophic production of renewable ethylene by engineered cyanobacteria: Steering the cell metabolism towards biotechnological use

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    Ethylene is a volatile hydrocarbon with a massive global market in the plastic industry. The ethylene now used for commercial applications is produced exclusively from nonrenewable petroleum sources, while competitive biotechnological production systems do not yet exist. This review focuses on the currently developed photoautotrophic bioproduction strategies that enable direct solar-driven conversion of CO2 into ethylene, based on the use of genetically engineered photosynthetic cyanobacteria expressing heterologous ethylene forming enzyme (EFE) from Pseudomonas syringae. The emphasis is on the different engineering strategies to express EFE and to direct the cellular carbon flux towards the primary metabolite 2-oxoglutarate, highlighting associated metabolic constraints, and technical considerations on cultivation strategies and conditional parameters. While the research field has progressed towards more robust strains with better production profiles, and deeper understanding of the associated metabolic limitations, it is clear that there is room for significant improvement to reach industrial relevance. At the same time, existing information and the development of synthetic biology tools for engineering cyanobacteria open new possibilities for improving the prospects for the sustainable production of renewable ethylene

    A combined photobiological-photochemical route to C-10 cycloalkane jet fuels from carbon dioxide via isoprene

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    The hemiterpene isoprene is a volatile C-5 hydrocarbon with industrial applications. It is generated today from fossil resources, but can also be made in biological processes. We have utilized engineered photosynthetic cyanobacteria for direct, light-driven production of bio-isoprene from carbon dioxide, and show that isoprene in a subsequent photochemical step, using either near-UV or simulated or natural solar light, can be dimerized into limonene, paradiprene, and isomeric C10H16 hydrocarbons (monoterpenes) in high yields under photosensitized conditions (above 90% after 44 hours with near-UV and 61% with simulated solar light). The optimal sensitizer in our experiments is di(naphth-1-yl)methanone which we use with a loading of 0.1 mol%. It can also easily be recycled for subsequent photodimerization cycles. The isoprene dimers generated are a mixture of [2 + 2], [4 + 2] and [4 + 4] cycloadducts, and after hydrogenation this mixture is nearly ideal as a drop-in jet fuel. Importantly the photodimerization can be carried out at ambient conditions. However, the high content of hydrogenated [2 + 2] dimers in our isoprene dimer mix lowers the flash point below the threshold (38 degrees C); yet, these dimers can be converted thermally into [4 + 2] and [4 + 4] dimers. When hydrogenated these monoterpenoids fully satisfy the criteria for drop-in jet fuels with regard to energy density, flashpoint, kinematic viscosity, density, and freezing point. Life-cycle assessment results show a potential to produce the fuel in an environmentally sustainable way
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