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Numerical solution of the cavitation bubble dynamics
Münster, Filip ; Himr, Daniel (referee) ; Rudolf, Pavel (advisor)
This thesis deals with the numerical solution of cavitation bubble dynamics and with cyanobacteria gas vesicle behaviour. A program for the numerical calculation of bubble dynamics is created using the Rayleigh-Plesset equation and its modifications. Subsequently, bubbles of different sizes are investigated during acoustic cavitation with various driving frequencies. Furthermore, a model for hydrodynamic cavitation is created. The model combines CFD computation of flow in the Venturi nozzle with the cavitation bubble dynamics calculation. The last part of the work is dedicated to cyanobacteria gas vesicle behaviour in a variable pressure field and during passage through the Venturi nozzle.
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Preparation of microbial, plant and algal extracts to use in cosmetics for infants
Janderová, Šárka ; Dzurická, Lucia (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with the preparation of a cosmetic product for infants with the addition of active substances from cyanobacteria, microalgae, or plants. In the theoretical part, a review was made, which not only summarizes the basic information about these organisms, but also the antioxidants contained in these microorganisms. In the practical part, several types of extracts from cyanobacteria, algae and plants were prepared and characterized. The content of phenolic substances, chlorophylls and content of carotenoids were measured spectrophotometrically. Content of soluble proteins was determined by Hartree-Lowry method and the fatty acid profile in biomass was obtained by GC. Furthermore, the SPF factor was measured using the spectrophotometric method the Mansur equation. Antioxidant activity was determined by using the TEAC method. Finally, two of the best extracts were selected for the preparation of cosmetic emulsions. The sensory analysis of prepared emulsions was performed for the period of two weeks.
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A comparison of metabolic activity and use of microalgae and pigment-formed yeasts
Szotkowski, Martin ; Kočí, Radka (referee) ; Márová, Ivana (advisor)
Carotenoids are natural pigments occurring in plants and many microorganisms, such as algae, yeast and bacteria. They represent the most common group of antioxidants with significant biological effect. Lipids are an essential component of all living organisms. They are the source and the reservoir of energy for organisms, which can also be used in the petrochemical industry for the production of biofuels. This thesis deals with the production properties of carotenoids and lipids by selected strains of yeasts, algae, and canobacteria, in order to apply the acquired knowledge and find cheap suitable alternatives for microbial biotechnological production of these metabolites using waste substrates. Carotenoids, coenzyme Q, and ergosterol in cells were determined by liquid chromatography. The lipid content and fatty acid profile was analyzed by gas chromatography. Cell morphology and localization of selected metabolites were analyzed by fluorescence lifetime imaging microscopy. In this work yeast genera Sporobolomyces, Cystofilobasidium and Rhodotorula were used. As the representatives of the algae and cyanobacteria strains of Desmodesmus, Cyanothece, Chlamydomonas, Synechoccocus and Chlorella strains were studied. In the overall comparison, the yeast strains were more productive than algae and cyanobacteria. The highest carotenoid production was found in S. pararoseus, C. capitatum and R. mucilaginosa cells, while the highest lipid yield was observed in strains of C. infirmominiatum and S. metaroseus.
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Characterization of biological effects of extracts obtained from yeasts and autotrophic microorganisms
Špačková, Dominika ; Bendová, Agáta (referee) ; Szotkowski, Martin (advisor)
Carotenogenic yeasts and microscopic autotrophic microorganisms are increasingly being studied in the biotechnology industry because of their ability to produce a variety of substances with a wide range of utilization. These substances mainly include lipids and carotenoids, which are used in the food and pharmaceutical industries. The aim of this bachelor thesis is to determine the way these microorganisms behave in the presence of stress factors, and which of them would have a positive effect on the production of metabolites that can be further used in various industries. The theoretical part is dedicated to a characterization of substances produced by carotenogenic yeasts, cyanobacteria and microalgae, which will be further analyzed in the experimental part. The metabolites mainly include carotenoids, which are a wide group of naturally occurring pigments that possess, among other things, antioxidant and provitamin activity. No less important substances produced by these organisms are lipids, which are part of cell membranes, they also serve as a reservoir of energy, and the substances contained in lipids are part of the precursors of many hormones. Yeast cell walls also contain -glucans, which have many beneficial effects on immunity and human health. Due to this fact, interest in their research have been rising recently. The analytical methods used to determine these substances are also mentioned, as well as stress factors and their effects on the cells of the mentioned organisms. The experimental part deals with the exposure of these microorganisms to oxidative stress and stress caused by heavy metals. The aim was to analyze which concentrations of these stress factors are lethal to microorganisms, and which of them are optimal for increase of the production of the above-mentioned substances. Of the yeast strains, the strains Sporidiobolus pararoseus and Rhodotorula mucilaginosa achieved increased production of metabolites due to selenate ions. In contrast, cobalt had a beneficial effect only on the accumulation of lipids and -glucans in cells. The positive effect of selenium was also observed in the strain Chlorella minutissima and Arthrospira maxima, however, the most remarkable changes in the production of metabolites were achieved by the addition of the optimal concentration of the solution inducing oxidative stress.
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Process of destratification at Brno dam reservoir
Marek, Tomáš ; Maršálková, Eliška (referee) ; Palčík,, Jiří (advisor)
This thesis deals with the process of destratification at the Brno dam reservoir within the activities of a larger project "Clean Svratka", aimed to improvement of water quality in the catchment area upstream the Brno dam. At the Brno dam the project "Implementation of measures at the Brno Reservoir" has been in progress for the third year. Its aim is the proposal and implementation of measures to suppress the cyanobacteria mass development in the dam lake. One of the key measures is aeration and mixing of dam water through a 20 aeration tower. The theoretical part of this thesis focuses on seasonal conditions in the dam lake, the technology suitable for destratification and aeration and possibilities of their use. In the practical part of the thesis the seasonal destratification and the impact of meteorological conditions are monitored.
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Mutual interaction of magnetic field and cavitating flow
Harazin, Přemysl ; Štigler, Jaroslav (referee) ; Rudolf, Pavel (advisor)
Presented work consists of research and experimental part. Main focus of the research part is on mutual interaction between magnetic field and water and between magnetic field and cavitating flow. Prediction of the result is almost impossible, because the opinions on the effects differ, sometimes even go against each other. Experimental part consisted of three trials with permanent magnets. Electromagnetic probe was employed for measuring of the voltage. It appears, that magnetic field affects the cavitation, because in all of the trials the measured voltage changed after the switch from non-cavitating to cavitating flow. The change of the voltage was not great enough, thus application of this phenomenon in practice cannot be recommended.
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Photosynthetically produced hydrogen
Osipenko, Elena ; Němcová, Yvonne (advisor) ; Ráček, Jan (referee)
Bio-hydrogen from microalgae and cyanobacteria has attracted commercial awareness due to its potential as an alternative, reliable and renewable energy source. Photosynthetic hydrogen production from algae and cyanobacteria can be interesting and promising options for clean energy, because hydrogen is produced at ambient temperature and pressure and releases only water as a by-product. The energy of sunlight is used to split the water molecule into protons (H+), electrons (e-) and O2. The protons and electrons are then recombined with the help of the enzymes hydrogenase or nitrogenase (in the case of cyanobacteria) to form H2. Both of these enzymes are sensitive to O2 and therefore require the processes of H2 formation and CO2 fixation to be separated. This bachelor's thesis aims to describe the principle of H2 formation in different cyanobacterial and algal systems and mention the problems and limitations. The thesis also presents recent approaches, including genetic and metabolic engineering of cyanobacteria and algae or co-culturing of algae and bacteria, where an anaerobic environment is created by enhanced bacterial respiration.
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Vliv železa a jeho bioakumulace v sinici Spirulina a mikrořase Chlorella
Koláčková, Kristýna
Iron is a trace element playing a key role in a number of metabolic pathways important for all living organisms. Iron deficiency is one of the most widespread problems in human nutrition. In order to possibly use Spirulina and Chlorella as dietary supplements for people suffering from iron deficiency sideropenic anemia, the effect of different concentrations of iron in the medium (0 mg/L, 5 mg/L and 10 mg/L) on its amount in the biomass was investigated. The optimal amount of Fe2+ in the medium was determined using spectrophotometric determination of optical density (OD) and iron content in Arthrospira maxima and Chlorella vulgaris biomass, which was determined by atomic absorption spectrometry (AAS). Expression analysis, performed in a model organism with a sequenced whole genome, Chlamydomonas reinhardtii, revealed the effect of selected concentrations of Fe2+ on the genes of the oxidative stress regulatory pathway. The results of the above analyzes show what are the optimal levels of iron cations for the growth of the studied organisms and its accumulation in them. The effect of iron in the chosen form, its assimilation and bioaccumulation in the cyanobacteria Spirulina and Chlorella microalgae was thus clarified.
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Zhodnocení účinnosti srážení fosforu na přítoku do nádrže Plumlov
Košťálová, Alena
This bachelor's thesis on the topic "Evaluation of the efficiency of phosphorus reduction at the inflow to the Plumlov reservoir" is processed as a literature and research with subsequent processing of the results obtained from field measurements. In the first part, it focuses on introducing the reader to the issue of eutrophication, water pollution or how works and what affects the chemistry of water. In the practical part, it deals with the issue of phosphorus precipitation in water flow. This system is implemented by Povodí Moravy, s.p. and the task of the work was to regularly monitor for one calendar year the development of the phosphorus content, during its constant precipitation. The results of the measurements were shown graphically, and illustrative maps are also attached, giving the reader a closer look at the location of the water course within the Czech Republic.
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