National Repository of Grey Literature 95 records found  beginprevious63 - 72nextend  jump to record: Search took 0.00 seconds. 
Raman spectrometry of pigments of cyanobacteria, algae and lichens in the astrobiology context
Kovács, Michal ; Jehlička, Jan (advisor) ; Osterrothová, Kateřina (referee)
This work deals with the possibility of Raman spectroscopical identification of selected biomarkers of extremophile species. It focuses mainly on selected cyanobacteria, algae and lichens with an emphasis on the ability to detect carotenoids. These pigments exhibit three characteristic bands of Raman spectra which represent stretching vibrations C=C; C-C and bending vibration C-CH3 in molecules of carotenoids. Raman spectra were measured not only by laboratory microspectrometers (λ - 514 nm and 532 nm), but also by portable and handheld spectrometers (λ - 532 nm, 785 nm and 700 - 1100 nm). In the case of cyanobacteria, the spectroscopical analysis was performed also on the fractions obtained by high performance liquid chromatography (HPLC). This work critically evaluates the possibilities of Raman spectroscopy to identify the carotenoids of cyanobacteria, algae and lichens. Besides the signal of carotenoids, interpretation of other bands in the Raman spectra corresponding to the presence of other biomarkers is given here for selected samples. The obtained Raman spectra of carotenoids should be interpreted with great caution, because of the ifluence of several factors, which potentially cause unsystematic shifts in the positions of Raman bands (carotenoids bond in biological tissue, interactions with...
The issue of water quality of bathing areas in Vltava basin and their impact on recreation
BRŮŽKOVÁ, Radka
The diploma thesis deals with the issue of water quality in bathing areas on the Vltava River. I concretely concentrated on the quality of water on dams Lipno, Orlík and Slapy. There were two aims. The first of them was observing of selected physical-chemical and microbiological indicators and algae in bathing waters of dams Lipno, Orlík, Slapy situated on the Vltava River between years 2006 and 2016. The second aim was observing of changes in water quality in the Vltava River and dams Lipno, Orlík, Slapy in the direction as river flows in the period of ten years. The thesis is divided into the theoretical and the practical part. The issue of water quality for bathing, indicators for its evaluation and the description of chosen dams on the Vltava River are written in the theoretical part. The practical part was realized by the method of the secondary analysis of data. The analysed data were gained from The National Health Institute with the permission of The Ministry of Health. The next data were given by The State Enterprise, Povodí Vltavy. The time period for the analysis was from years 2006 to 2016. Data gained were described in charts and graphs by the usage of computer programme Microsoft Excel. The part of this thesis was also the outdoor research. The gained results could be used as the source of information not only for general public but also for towns, villages or keepers of recreation facilities situated in this area. On the bases of discovered facts, data, documents, materials, outdoor research and their evaluation there will be given the complete view on the water quality in the dams intended for recreation with prediction about the future progress.
Use of autotrophic algae to production of biomass and some metabolites
Chrástová, Nikola ; Kostovová, Iveta (referee) ; Márová, Ivana (advisor)
Chlorophyll and carotenoids are natural pigments and antioxidants. These pigments are suitable for use in the pharmaceutical, cosmetics or food industries. Lipids are another major metabolite of algae and are a potential feedstock for biofuel production. This bachelor thesis deals with the cultivation of selected genera of autotrophic algae, subsequent isolation of these selected metabolites and their application. The theoretical part focuses on the description of the algae, the metabolites produced, the cultivation and the chosen methods. The experimental part deals with the optimization of the cultivation of algae of the genera Chlorella, Chlamydomonas and Desmodesmus, depending on the chosen medium and intensity of illumination, determination and quantification of algal biomass. Further, extraction of lipidic and carotenoid substances and determination by HPLC and GC was performed. In the overall comparison, the best producer of biomass is the algal genus Desmodesmus and the highest production of pigments and lipid substances was reached in algae of the genus Chlamydomonas.
Climate change and related species shift in algal and cyanobacterial communities.
Kosová, Alena ; Němcová, Yvonne (advisor) ; Pichrtová, Martina (referee)
Therefore, species are expected to move towards the poles in response to shifting climate ones. This warming trend also includes the establishment of tropical algae in temperate systems of the Northern Hemisphere. Numerous tropical and subtropical species of microalgae have been reported in the last decades in the continental waters of Europe. The aims of the Bachelor thesis are to summarize articles concerning changes in diversity and dynamics focused on algae and blue-green algae in temperate water bodies. Several hypotheses about the origin, modes of distribution and the ability of microorganisms to overcome stressful condition during the transportation are also discussed in this work.
Biogeography and specificity of Asterochloris photobionts
Řídká, Tereza ; Škaloud, Pavel (advisor) ; Vondrák, Jan (referee)
This diploma thesis has focused on the diversity and biogeography of Asterochloris photobionts. Since no study so far has been published on the biogeography of symbiotic microorganisms, the presented thesis is the first attemp to trace the biogeographic distribution and endemism of symbionts. By gathering 121 Asterochloris sequences obtained from lichen thalli sampled outside Europe and America, the diversity within the genus increased dramatically. The phylogenetic analysis based on the concatenated alignment of ITS rDNA and actin sequences obtained from Cladonia and Stereocaulon photobionts revealed 28 differently supported clades. Of them, eight lineages were newly discovered. Three environmental factors explaining the best the distribution pattern of Asterochloris photobionts were selected according to the statistical tests of the phylogenetic signal: two different types of biogeographical ecoregions and the substrate type. In general, the genus Asterochloris is distributed cosmopolitally, with a very low rate of endemism. Newly obtained data indicate that the restricted distribution of any photobiont clade is not caused by either historic or biological factors, but more likely by specific climatic or habitat preferences.
Morphological strategies of photoautotrophic protists under various environmental conditions.
Ševčíková, Tereza ; Kulichová, Jana (advisor) ; Pichrtová, Martina (referee)
The aim of this thesis is to provide a comprehensive overview of morphological adaptation of photoautotrophic protists to various environmental conditions and to describe the influence of their shape and size for different life strategies. Thesis summarizes overview of the main factors affecting the natural mikroalgal community and shows their relevance for life of photoautotrophic protists. These factors include availability of nutrients, pH, temperature, penetration of light and predation. Next part focuses on different methodological approaches and attitudes, how to investigate, measure and explain morphological features.
Vertical migration of benthic cyanobacteria and algae
Mensa, Jakub ; Neustupa, Jiří (advisor) ; Němcová, Yvonne (referee)
Vertical migration has been observed in different taxonomic groups of benthic microalgae and cyanobacteria in both marine and freshwater habitats. It seems to be an advantageous survival strategy of motile photoautotrophic organisms. In general, algae inhabiting tidal environments migrate up to the sediment surface during daytime emersion and then migrate below the surface prior to high tide or dusk. Freshwater microalgae stay on the surface during daytime and migrate below the surface before dusk. The migratory rhythm can be controlled or influenced by light, waves, subsurface nutrient supplies and reducing conditions in the sediment. Sometimes, the rhythm persists even in constant conditions and it seems to be controlled by biological clock system.
Sexual reproduction of ochrophyte algae
Procházková, Kateřina ; Eliáš, Marek (advisor) ; Kulichová, Jana (referee)
Sexual reproduction is one of the specific features of eukaryotes. Almost all the knowledge that we have about the sexual process is based on studies conducted on animals and plants. In fact, we know only a tiny fraction of what protist organisms could reveal about distribution and other aspects of the sexual process. For the vast majority of them we miss any evidence that the sexual process actually occurs. However, it is conceivable that the putative protist asexuality is only a human artifact. Likewise, for most ochrophyte algae, which are the main subject of this thesis, the sexual process is unknown. It has been observed only in individuals belonging to six of the sixteen hitherto described classes of Ochrophyta. In some cases, an enviromnental factor that stimulates the formation of gametes was also found. The gradual clarification of the phylogeny that we can expect in the years coming, along with knowledge of biology of ochrophyte algae, can provide more information about sexuality in this group.
Ecotoxicity of nanomaterials
Viltová, Naďa ; Kočí, Vladimír (advisor) ; Motejlová, Hana (referee)
Recently, nanotechnology has gained a lot of interest and the likelihood of emission of nanomaterials into the enviromment increases as well as the risk of its adverse effects. There is very little information about the behaviour and effects of nanomaterials in the environment, but so far the studies indicate an increasing rate of adverse effects of nanomaterials with decreasing particle size. The aim of this work was to determine the toxicity of nanoparticles of CeO2 of the size of 47,7 nm and 2,1 nm on a green, freshwater algae Desmodesmus subspicatus. Furthermore, the influence of surfactant addition on the toxicity of both substances was evaluated. The results showed that the particle of 2,1 nm showed a higher toxicity than the bigger particles, which is consistent with that was found in the literature. After addition of surfactant, an increase of toxicity was observed increase for both forms
Příspěvek k poznání vegetace sinic a řas vodních biotopů na Nepomucku
HAZUKOVÁ, Václava
The algological research was conducted in the surroundings of Nepomuk. In total, 9 fishponds and 2 streams were investigated over two years. Samples of net phytoplankton, periphyton and phytobenthos were collected in spring, summer and autumn. Moreover, various environmental variables were measured at each sampling site. Specimens were identified to the lowest taxonomic level possible and the relative abundance was assessed. Seasonal fluctuations and changes in the species composition among sampling sites were compared and discussed. The influence of environmental variables on changes in planktic and benthic assemblies was analysed. The list of species and the photodocumentation are presented.

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