14 research outputs found

    Extracellular Phytase Production by the Wine Yeast S. cerevisiae (Finarome Strain) during Submerged Fermentation

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    One of the key steps in the production of phytases of microbial origin is selection of culture parameters, followed by isolation of the enzyme and evaluation of its catalytic activity. It was found that conditions for S. cerevisiae yeast culture, strain Finarome, giving the reduction in phytic acid concentration of more than 98% within 24 h of incubation were as follows: pH 5.5, 32 °C, continuous stirring at 80 rpm, the use of mannose as a carbon source and aspartic acid as a source of nitrogen. The highest catalytic activity of the isolated phytase was observed at 37 °C, pH 4.0 and using phytate as substrate at concentration of 5.0 mM. The presence of ethanol in the medium at a concentration of 12% v/v reduces the catalytic activity to above 60%. Properties of phytase derived from S. cerevisiae yeast culture, strain Finarome, indicate the possibility of its application in the form of a cell’s free crude protein isolate for the hydrolysis of phytic acid to improve the efficiency of alcoholic fermentation processes. Our results also suggest a possibility to use the strain under study to obtain a fusant derived with specialized distillery strains, capable of carrying out a highly efficient fermentation process combined with the utilization of phytates

    Experience Gained When Using the Yuneec E10T Thermal Camera in Environmental Research

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    Thermal imaging is an important source of information for geographic information systems (GIS) in various aspects of environmental research. This work contains a variety of experiences related to the use of the Yuneec E10T thermal imaging camera with a 320 × 240 pixel matrix and 4.3 mm focal length dedicated to working with the Yuneec H520 UAV in obtaining data on the natural environment. Unfortunately, as a commercial product, the camera is available without radiometric characteristics. Using the heated bed of the Omni3d Factory 1.0 printer, radiometric calibration was performed in the range of 18–100 °C (high sensitivity range–high gain settings of the camera). The stability of the thermal camera operation was assessed using several sets of a large number of photos, acquired over three areas in the form of aerial blocks composed of parallel rows with a specific sidelap and longitudinal coverage. For these image sets, statistical parameters of thermal images such as the mean, minimum and maximum were calculated and then analyzed according to the order of registration. Analysis of photos taken every 10 m in vertical profiles up to 120 m above ground level (AGL) were also performed to show the changes in image temperature established within the reference surface. Using the established radiometric calibration, it was found that the camera maintains linearity between the observed temperature and the measured brightness temperature in the form of a digital number (DN). It was also found that the camera is sometimes unstable after being turned on, which indicates the necessity of adjusting the device’s operating conditions to external conditions for several minutes or taking photos over an area larger than the region of interest

    Development of blue stain in mechanically harvested Scots pine (Pinus sylvestris) logs during storage

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    Blue stain is a type of discoloration that considerably lowers the aesthetic qualities of wood. During harvesting, fungal inoculum finds its way into the wood through places of cutting, delimbing, and damage to the tree stem. The development of peripheral blue stain in the logs of Scots pine (Pinus sylvestris L.) due to damage by a harvester head was investigated, using logs felled and delimbed with a chainsaw as reference. The development of blue stain was related to the age class of the stand, the date of felling, and the microclimatic conditions of the wood storage place. The mean surface area of blue stain in logs produced with the harvester was almost 35 cm2, approximately 30% larger than that of the reference logs. In stands of the fourth age class (diameter at breast height 32 cm), the surface of blue stain was more than two times larger than that of stands of the third age class (diameter at breast height 24 cm). The mean area of blue stain in wood stored after spring felling (19.3 cm2) was about 50% of that after summer felling (38.2 cm2). In particular, the development of blue stain in logs obtained with a harvester was visible between weeks 6 and 9 after spring felling and between weeks 3 and 6 after summer felling. For both felling dates, the range of blue stain depended less on air temperature around the wood stack and depended more on the duration of storage.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

    Theory of Optical Spectra of Photosystem II Reaction Centers: Location of the Triplet State and the Identity of the Primary Electron Donor

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    Based on the structural analysis of photosystem II of Thermosynechococcus elongatus, a detailed calculation of optical properties of reaction-center (D1–D2) complexes is presented applying a theory developed previously. The calculations of absorption, linear dichroism, circular dichroism, fluorescence spectra, all at 6 K, and the temperature-dependence of the absorption spectrum are used to extract the local optical transition energies of the reaction-center pigments, the so-called site energies, from experimental data. The site energies are verified by calculations and comparison with seven additional independent experiments. Exciton relaxation and primary electron transfer in the reaction center are studied using the site energies. The calculations are used to interpret transient optical data. Evidence is provided for the accessory chlorophyll of the D1-branch as being the primary electron donor and the location of the triplet state at low temperatures

    Quantitative Trait Loci for Yield and Yield-Related Traits in Spring Barley Populations Derived from Crosses between European and Syrian Cultivars

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    <div><p>In response to climatic changes, breeding programmes should be aimed at creating new cultivars with improved resistance to water scarcity. The objective of this study was to examine the yield potential of barley recombinant inbred lines (RILs) derived from three cross-combinations of European and Syrian spring cultivars, and to identify quantitative trait loci (QTLs) for yield-related traits in these populations. RILs were evaluated in field experiments over a period of three years (2011 to 2013) and genotyped with simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers; a genetic map for each population was constructed and then one consensus map was developed. Biological interpretation of identified QTLs was achieved by reference to Ensembl Plants barley gene space. Twelve regions in the genomes of studied RILs were distinguished after QTL analysis. Most of the QTLs were identified on the 2H chromosome, which was the hotspot region in all three populations. Syrian parental cultivars contributed alleles decreasing traits' values at majority of QTLs for grain weight, grain number, spike length and time to heading, and numerous alleles increasing stem length. The phenomic and molecular approaches distinguished the lines with an acceptable grain yield potential combining desirable features or alleles from their parents, that is, early heading from the Syrian breeding line (Cam/B1/CI08887//CI05761) and short plant stature from the European semidwarf cultivar (Maresi).</p></div
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