48 research outputs found

    Lipid Production From Waste Materials in Seawater-Based Medium by the Yeast Yarrowia lipolytica

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    The global limitation of fossil fuels impels scientists to search for new energy sources. A good alternative is biodiesel produced from crop plants. However, its production requires huge quantities of farmland, fertilizers and fresh water, which is in conflict with the human demand for water for consumption and land for food production. Thus, production of single cell oil (SCO) by oleaginous microorganisms remains the best solution for the coming years. Whereas most microorganisms require fresh water for proper cell metabolism, in this study we demonstrate that the unconventional yeast Yarrowia lipolytica is able to produce huge quantities of fatty acid in seawater-based medium. Here we shown that Y. lipolytica is able to produce fatty acids in medium based on seawater and crude glycerol as the main carbon source, which allows for low-cost production of SCO, is beneficial for industrial application and is ecologically friendly

    Distinct Roles of ComK1 and ComK2 in Gene Regulation in Bacillus cereus

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    The B. subtilis transcriptional factor ComK regulates a set of genes coding for DNA uptake from the environment and for its integration into the genome. In previous work we showed that Bacillus cereus expressing the B. subtilis ComK protein is able to take up DNA and integrate it into its own genome. To extend our knowledge on the effect of B. subtilis ComK overexpression in B. cereus we first determined which genes are significantly altered. Transcriptome analysis showed that only part of the competence gene cluster is significantly upregulated. Two ComK homologues can be identified in B. cereus that differ in their respective homologies to other ComK proteins. ComK1 is most similar, while ComK2 lacks the C-terminal region previously shown to be important for transcription activation by B. subtilis ComK. comK1 and comK2 overexpression and deletion studies using transcriptomics techniques showed that ComK1 enhances and ComK2 decreases expression of the comG operon, when B. subtilis ComK was overexpressed simultaneously

    Copernicus Program as a source of information on the dominant leaf type in Poland – assessment of the accuracy of the national high resolution layer

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    Information on the spatial distribution and variability of forests is important in monitoring of forest resources, biodiversity assessment, threat prevention, estimation of carbon content and forest management. The Pan−European High Resolution Layers (HRLs) produced as part of the European Earth Monitoring Programme – Copernicus provide detailed information on the land cover characteristics in Europe. The HRLs are produced using satellite imagery based on an interactive rule−based classification. There are the following HRL themes: imperviousness, forest, water and wetness and grasslands. The HRLs are available for the reference year 2012 and 2015, at the spatial resolution of 20 m. The forest related HRL consists of tree cover density, dominant tree type and forest type products. In this study, we performed a) the qualitative and quantitative analysis of the accuracy of the dominant leaf type (DLT) layer for the 2015 year at the national scale, and b) detailed analysis of the data quality at the forest stand level over the selected forest districts. The DLT layer was compared with the national orthophotos. The detailed analysis was carried out using Sentinel−2 images and forest inventory data obtained from the Forest Data Bank over the selected forest districts. The accuracy analysis of the national DLT layer revealed the high omission error equal to 18.8%, and lower commission error of 5.4%. The omission error is mostly related to the omitted orchards and young forest plantations, which are included in the DLT layer. The commission error of the broadleaved forest is related mostly to the small patches of coniferous forest that was misclassified as broadleaved. In general, commission errors were identified more frequently in broadleaved forest than in the coniferous forest. In many locations the patches of coniferous forest were misclassified as broadleaved forest. In general, the area of the broadleaved forest is overestimated

    Determination of the actual forest area in Poland based on the available spatial datasets

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    Several studies discussed a disagreement concerning forest extent in Poland between land cadaster and status on the ground. The aim of the paper was to assess the actual forest extent in Poland based on an existing spatial datasets such as: Digital Forest Map (covering explicitly the State Forests), Topographic Database, Database of Parcel Identification System, High Resolution Layer (Copernicus Land Monitoring product based on classification of satellite data) and National Forest Data Bank. The geospatial data analyses were preceded by an accuracy assessment of the available datasets, which allowed to assign weights to each of the dataset. The result of this project was the actual forest extent map, which refers to the national definition of forest as defined in the Forest Act of 28 September 1991 (forest by definition is a homogeneous area of 0.1 hectares). This includes all forms of ownership forests and areas that are forested, but officially recorded as non−forest. Moreover, the map of the forest extent under the Kyoto Protocol, including areas that meet the criteria of actual forest extent map and additionally forest areas designed or used for housing, recreation, infrastructure, and other industrial and agricultural areas (e.g.: permanent crops – orchards) were determined. The results confirmed that the actual forest extent is higher by almost 800 thousand hectares then the official statistics provided by the Central Statistical Office of Poland. According to the official statistics forest in Poland covers 29.4% of the country, however this study revealed that 32% of the country, considering the national forest definition, and 33.5%, considering the forest definition under the Kyoto Protocol, is occupied by forest. It showed the need for the land cadaster update. Precise information on spatial distribution of forest extent is crucial for the national purposes i.e. reporting, implementation of the National Afforestation Program and also for the international commitments under the climate convention to determine the accurate forest carbon content and carbon dioxide sequestration

    Map of historic names as a form of cultural heritage protection: An example of Wałeckie Lakeland

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    W artykule przedstawiono okoliczności podjęcia badań oraz cele projektu „Przywracanie zabytkowych polskich nazw za pomocą map (na przykładzie Pojezierza Wałeckiego)”. Opisano również sposoby pozyskiwania nazw oraz metodykę opracowywania map nazw zabytkowych. Nazwy zbierane były na trzy sposoby: w archiwach, z map oraz w terenie. Na podstawie tych danych powstały wykazy obiektów z zabytkową nazwą oraz ich prezentacja graficzna na papierowych mapach. Digitalizacja oraz utworzenie bazy danych w systemie informacji geograficznej (GIS) umożliwiło opracowanie 17 arkuszy mapy zabytkowego nazewnictwa polskiego na Pojezierzu Wałeckim. Mapa ta ma być formą upowszechniania nazw na badanym obszarze oraz uświadamiać lokalną społeczność o zanikaniu nazw ze słowiańskim źródłosłowem. Nazwy te powinny zostać przywrócone w świadomości społecznej, gdyż są elementem dziedzictwa kulturowego tego regionu.The article presents the circumstances of undertaking research and the objectives of the project "Restoring the historic Polish names using maps (example of Wałeckie Lakeland)". Also there are described methods of collecting and mapping historical place names. Historic names were collected in three ways: in the archives, from maps and in the field. On the basis of these data the lists of objects with historic names were formed and their graphical representation was made on paper maps. The digitization of these data and the creation of a database of Geographic Information System (GIS) has enabled to produce 17 sheets of a map of Polish historical naming in Wałeckie Lakeland. This map is intended to disseminate historic names at the study area, and to raise local community awareness about the problem of the disappearance of the names with the Slavic root. These names should be restored in the public consciousness, because they are part of the cultural heritage of the region

    Mutation in yl-HOG1 represses the filament-to-yeast transition in the dimorphic yeast Yarrowia lipolytica

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    Abstract Background Yarrowia lipolytica is a dimorphic fungus, which switches from yeast to filament form in response to environmental conditions. For industrial purposes it is important to lock cells in the yeast or filamentous form depending on the fermentation process. yl-Hog1 kinase is a key component of the HOG signaling pathway, responsible for activating the osmotic stress response. Additionally, deletion of yl-Hog1 leads to increased filamentation in Yarrowia lipolytica, but causes significant sensitivity to osmotic stress induced by a high concentration of a carbon source. Results In this study, we tested the effect of point mutations on the function of yl-Hog1 protein kinase. The targets of modification were the phosphorylation sites (T171A-Y173A) and the active center (K49R). Introduction of the variant HOG1-49 into the hog1∆ strain partially improved growth under osmotic stress, but did not recover the yeast-like shape of the cells. The HOG1-171/173 variant was not functional, and its introduction further weakened the growth of hog1∆ strains in hyperosmotic conditions. To verify a genetic modification in filament form, we developed a new system based on green fluorescent protein (GFP) for easier screening of proper mutants. Conclusions These results provide new insights into the functions of yl-Hog1 protein in dimorphic transition and constitute a good starting point for further genetic modification of Y. lipolytica in filament form

    The Overexpression of YALI0B07117g Results in Enhanced Erythritol Synthesis from Glycerol by the Yeast Yarrowia lipolytica

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    The unconventional yeast Yarrowia lipolytica is used to produce erythritol from glycerol. In this study, the role of the erythrose reductase (ER) homolog YALI0B07117g in erythritol synthesis was analyzed. The deletion of the gene resulted in an increased production of mannitol (308%) and arabitol (204%) before the utilization of these polyols began. The strain overexpressing the YALI0B07117g gene was used to increase the erythritol yield from glycerol as a sole carbon source in batch cultures, resulting in a yield of 0.4 g/g. The specific consumption rate (qs) increased from 5.83 g/g/L for the WT strain to 8.49 g/g/L for the modified strain and the productivity of erythritol increased from 0.28 g/(L h) for the A101 strain to 0.41 g/(L h) for the modified strain. The application of the research may prove positive for shortening the cultivation time due to the increased rate of consumption of the substrate combined with the increased parameters of erythritol synthesis
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