Spelling suggestions: "subject:"karotenoidy""
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Ramanova spektrometrie karotenoidů vybraných mikroorganismů / Raman spectrometry of carotenoids of selected microorganismsNovotná, Julie January 2014 (has links)
In this thesis Raman spectroscopy is evaluated as a tool of identification and discrimination of carotenoids from microbial biomass. Microorganisms, halophilic or nonhalophilic, belong to Cyanobacteria, Proteobacteria, Chlorophyta, Rhodophyta and to others. Biomass was cultiveted under laboratory conditions and yielded varied colours. Raman spectra were recorded succesfully from lyophilized biomass by excitation wavelenth 514.5 nm (dispersive Raman microspectrometr) and 1064 nm (FT Raman spectrometer). Results were compared with Raman spectroscopic data from pigment extracts. Spectra of carotenoids are characterized by the main Raman bands υ1, υ2 a υ3 due to C=C stretching, C-C stretching and C-CH3 deformation. HPLC/UV-VIS allows effective pigment separation from extracts and detection of separated pigments by UV-VIS analyzator. Assessment of Raman analysis and its potential to detect microbial carotenoids are discused. Sarcinaxantin is an unusual carotenoid identified together with more common β - carotene. Raman spectroscopic results obtained on carotenoids recorded from colonies which accumulated more than one carotenoid need to be interpreted carefully. Powered by TCPDF (www.tcpdf.org)
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Zhášení tripletních stavů chlorofylů karotenoidy v tylakoidních membránách / Quenching of chlorophyll triplet states by carotenoids in thylakoid membranesVahalová, Petra January 2015 (has links)
Photosynthesis is one of the most important biological processes. The photosynthetic apparatus is protected against formation of reactive singlet oxygen by carotenoids. In this work, thylakoid membranes from spinach were studied, and the main aim was to explore the effect of a partial carotenoid removal on the protective function. Carotenes, which are nonpolar carotenoids, were removed from a part of the sample by hexane. About 90 % of carotenes were removed, as revealed by liquid chromatography. However, the high efficiency of chlorophyll triplet state quenching was not affected by the carotene removal. Therefore, it was concluded that the remaining carotenes are probably localized around reaction centres, where they are not accessible to hexane and where their protective function is the most important. At the same time, changes in optical spectra were observed, which were ascribed to structural modifications caused by the carotene removal from the outer parts of the complexes. The carotenoids removal probably caused detachment of outer light-harvesting complexes. This interpretation is supported by the fact that similar changes were observed in experiments with a detergent dodecyl maltoside. 1
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Excited States of Carotenoids and Their Roles in Light Harvesting SystemsKEŞAN, Gürkan January 2016 (has links)
Carotenoids are an extensive group of natural pigments employed by a majority of organisms on earth. They are present in most organisms, including humans, but can be synthesized only by plants and microorganisms. They perform two major roles in photosynthesis, often in partnership with the more prevalent chlorophylls (Chls) / bacteriochlorophylls (BChls): light-harvesting and photoprotection. Carotenoids absorb radiation in a spectral region inaccessible to Chls and BChls and transfer the absorbed energy to (B)Chls which, in turn, funnel it into the photosynthetic reaction center (RC). It is determined that the structures and dynamics of excited states of carotenoids found in photosynthetic proteins provide an explanation of their roles as light-harvesting and photoprotective agents. The conjugation length and the type of carotenoids play a big part in understanding the energy transfer from carotenoids to Chls and BChls, because excited-state properties of carotenoids are affected by number of conjugated C=C bonds and their structures. An accurate description of these states is, therefore, the crucial first step in explaining carotenoid photochemistry and understanding the interactions between carotenoids and other molecules in photobiological processes. The research in this thesis, femtosecond ultrafast transient absorption spectroscopy was used to study the light-harvesting function of carotenoids both in solvent and protein environment. The findings were supported with computational methods. Based on spectroscopic indications, the light-harvesting function of carotenoids has a bearing on their structures, and specific light-harvesting strategies are explicitly dependent with the structure of the light-harvesting complexes.
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Ekofyziologické a morfologické rozdíly mezi domácími a invazními populacemi \kur{Lythrum salicaria} L. / Ecophysiological and morphological differences between native and invasive populations of \kur{Lythrum salicaria} L.KAŠPAROVÁ, Františka January 2011 (has links)
Native to Europe and Asia, Lythrum salicaria is an invasive element on some other continents. Plants in the invaded areas are more robust, higher, and generally more successful compared to individuals in their original area. Based on my results these characteristics cannot be explained by neither higher photosynthesis, chlorophyll and carotenoid mass, nor specific leaf area.
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Ekofyziologické a morfologické rozdíly mezi domácími a invazními populacemi \kur{Lythrum salicaria} L. / Ecophysiological and morphological differences between native and invasive populations of \kur{Lythrum salicaria} L.KAŠPAROVÁ, Františka January 2011 (has links)
Native to Europe and Asia, Lythrum salicaria is an invasive element on some other continents. Plants in the invaded areas are more robust, higher, and generally more successful compared to individuals in their original area. Based on my results these characteristics cannot be explained by neither higher photosynthesis, chlorophyll and carotenoid mass, nor specific leaf area.
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Využití obrazové spektroskopie pro monitoring zátěže vegetace polutanty obsaženými v půdním substrátu Sokolovské hnědouhelné pánve / Application of imaging spectroscopy in monitoring of vegetation stress caused by soil pollutants in the Sokolov lignite basinMišurec, Jan January 2018 (has links)
Forests can be considered as one of the most important Earth's ecosystems not only because of oxygen production and carbon sequestration via photosynthesis, but also as a source of many natural resources (such as wood) and as a habitat of many specific plants and animals. Monitoring of forest health status is thus crucial activity for keeping all production and ecosystem functions of forests. The main aim of the thesis is development of an alternative approach for forest health status based on airborne hyperspectral data (HyMap) analysis supported by field sampling. The proposed approach tries to use similar vegetation parameters which are used in case of the current methods of forest health status assessment based on field inspections. It is believed that importance of such new methods will significantly increase in the time when the planned satellite hyperspectral missions (e.g. EnMap) will move into operational phase. The developed forest health monitoring approach is practically demonstrated on mature Norway spruce (Picea abies L. Karst) forests of the Sokolov lignite basin which were affected by long-term coal mining and heavy industry and therefore high variability of forest health status was assumed in this case. Two leaf level radiative transfer models were used for simulating spectral...
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