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Preparation and properties of cyanide-transforming enzymes and their analytical uses
Šťastná, Katarína ; Martínková, Ludmila (advisor) ; Čermáková, Michaela (referee)
Cyanides are compounds that are both naturally occurring and used in various industries. Their negative effects on human health, but also on the environment, have been demonstrated and their occurrence should therefore be monitored. The aim of this master thesis is the enzymatic determination of free cyanide, focusing on the characterization and application of specific enzymes within enzymatic cascades. The main objectives include the production and purification of key enzymes involved in cyanide conversion, namely cyanide hydratase (CynH), formamidase (AmiF), and cyanide dihydratase (CynD). The enzymes' catalytic properties and effectiveness in detecting cyanide were assessed. Spectrophotometric techniques were used to measure intermediates and products enzymatic reactions. The development, testing and optimization of enzyme cascades was carried out to demonstrate their feasibility and efficiency in cyanide determination. As a result, two selective, sensitive and rapid enzymatic assays for the detection of free cyanide have been developed. The proposed assays require small amounts of samples, enzymes and other components and enable rapid cyanide determination in less than two hours. Overall, this research contributes to the advancement of methods for cyanide analysis, with potential applications...
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Study of Electrochemical Processes on Neuromodulation Electrodes
Vašíček, Čeněk ; Kratochvíl, Matouš (referee) ; Ehlich, Jiří (advisor)
This bachelor’s thesis deals with experiments on a neuromodulation electrode made of a platinum-iridium alloy. The thesis is focused primarily on local changes in concentration of oxygen and hydrogen peroxide based on a potential, that is applied. Experiments take place in two electrolytes – PBS and a mixture of Dulbecco’s modified eagle medium with fetal bovine serum (90:10). The goal is to compare the electrode’s behaviour in these electrolytes, mainly on how the surface of the electrode would be affected, if the electrochemical reactions would happen when a different potential is applied, or if they would be less effective in general etc. Changes in oxygen and hydrogen peroxide concentrations are measured using amperometric sensors, with the added measurement of hydrogen peroxide with a spectrophotometric assay consisting of horseradish peroxidase (HRP) and 3,3‘,5,5‘-tetramethylbenzidine (TMB). The next thing that the thesis deals with is stability of hydrogen peroxide in both electrolytes used. In the last part, suggestions on next steps in this topic are mentioned.
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Issues of boron in water
Šípková, Helena ; Nevrlá, Jana (referee) ; Komendová, Renata (advisor)
This bachelor thesis is focused on boron and its compounds. It is dedicated to properties, sources and the use of these substances and their effects on living organisms. The emphasis is put on the issue of boron in water. In this work are possible forms of this element in water, legislative rules and regulations and methods of its determination described. The experimental part is focused on azomethine-H spectrophotometric analysis to identify the stability of boron samples and their possible preservation.
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The measurement of total alkaloids in tobacco
Pipková, Renata ; Vránová, Dana (referee) ; Omelková, Jiřina (advisor)
The aim of this diploma thesis is the assay of total alkaloids in different tobacco types. To measure the content of total alkaloids are utilized types of tobacco used for preparation of tobacco blends and consecutive production of cigarettes. The samples of analyzed tobacco include various countries of cultivation and different crop years. There is described tobacco as a plant, in it contained alkaloids and the utilization of tobacco in the theoretical part. In more detail it deals with the production and construction of cigarettes which is closely related to the content monitoring of total alkaloids in tobacco. The contents of total alkaloids are determined by the continuous flow analyzer- SKALAR. On this spectrophotometer are set the contens of reducing sugars as well. The comparison of total alkaloids contents and reducing sugars from the perspective of single tobacco types, countries of cultivation and crop years is clearly summarized in the experimental part of the thesis that was performed in the company Philip Morris ČR, a.s.
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Vegetable adaptogens - Schizandra chinensis
Pospíchalová, Lucie ; Půčková, Helena (referee) ; Kotlík, Josef (advisor)
This thesis deals with plant adaptogens (bioactive substances) in the plant Schisandra chinensis. The theoretical part is focused on characterization of the Schisandra genus, characterization of the Schisandra chinensis as a plant, its properties, occurrence and growing possibilities in the regional climate zone of the South Moravian Region as well as the use of this plant. Furthermore, adaptogens are described from a chemical point of view and their possible methods of isolation from individual parts of plants. The experimental part deals with extraction of fruits and leaves from plant Schisandra chinensis. Further, in the leaves extract was determined chlorophyll a, chlorophyll b and carotenoids by spectrophotometry, where the quantity of individual substances was confirmed for months April – May.
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Control and monitoring of parameters in microfluidic systems
Meloun, Jan ; Sekora, Jiří (referee) ; Čmiel, Vratislav (advisor)
This thesis discusses the construction of Microfluidic systems for a microscope. The theoretical part of this thesis deals with light, light’s behaviour and optical spectral analysis in some methods are discussed. Also, the use of the development platform Arduino with wireless data transfer for data visualization is mentioned. Methods for measuring pH are mentioned as well. The practical part is dedicated to the construction of the Microfluidic system with the use of Arduino, smart mobile devices and a developed mobile application including controlling liquid flow with the measured data visualization.
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Adaptogens in the Shizandra chinensis plant
Pospíchalová, Lucie ; Půčková, Helena (referee) ; Kotlík, Josef (advisor)
This diploma thesis deals with plant adaptogens (bioactive substances) in the plant Schisandra chinensis. The theoretical part is focused on characterization of the Schisandra genus, characterization of the Schisandra chinensis as a plant, its properties, occurrence and growing possibilities in the climate zone. Furthermore, The effects of these adaptogens on the organism and the prediction of possible use in food supplements are described. The experimental part deals with the extraction of fruits and leaves from plant Schisandra chinensis. Further, chlorophyll a, chlorophyll b in the leaves extract was determined by UV – VIS spectrophotometry, whereby the optimal amount 3:1 of chlorophyll was confirmed for the plants growing in optimal conditions. Finally, the concentration of the adaptogen schisandrin A in the dried fruits was from different kind of extraction measured by HPLC. In all fruits, schisandrin A was confirmed, but the amount is different in each sample.
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Spectrophotometric determination of chlorophyll
Rábová, Petra ; Vavrčíková, Veronika (referee) ; Řezáčová, Veronika (advisor)
This bachelor thesis is focused on determination of chlorophyll in leaves by the method of extraction spectrophotometry. The theoretical part provides information about photosynthesis, stress factors or plant adaptation, photosynthetic pigments (especially chlorophyll-a) and application of spectrophotometry and other methods of chlorophyll determination. The experimental part is focused on the application of the ecotoxicological test and, above all, it is evaluation by two independent methods. Specifically, it was determination of biomass growth inhibition and newly spectrophotometrical determination of chlorophyll mass. The results correlate with each other, therefore, the determination of chlorophyll seems to be an appropriate extension of usual evaluation methods of ecological tests.
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Study on pretreatment and hydrolysis of selected lignocellulose materials
Kovářová, Markéta ; Dvořák, Miloš (referee) ; Obruča, Stanislav (advisor)
This diploma thesis is focused on study of chemical and enzymatical hydrolysis of raw wood material. The aim of this work was to find the suitable method for pretreatment of selected lignocellulose materials. The theoretical part deals with characterization of lignocellulosic material and its components. There are also subscribed various pretreatment methods and their effect on hydrolysis of sawdust. In experimental part of the work the most appropriate approach of pretreatment and hydrolysis of sawdust was studied. Criteria for the selection of suitable method was concentration of saccharides as desired product of hydrolysis and also concentration of the most important microbial inhibitors - polyphenols. Application of 96% ethanol or 5% H2O2 were identified as the most promising pretreatment methods which enhanced yields of fermentable sugars about 30 %. Further, we also performed cultivation of bacteria Burkholderia cepacia and bacteria Burkholderia sacchari using solution obtained by hydrolysis of lignocellulose material.
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Monitoring of the contents of phosphorus and nitrogen in wastewater
Herka, Milan ; Repková, Martina (referee) ; Vávrová, Milada (advisor)
This master´s thesis is focused on the occurrence of phosphorus and nitrogen in effluents and methods of their determination. In the theoretical part of the thesis describes methods for the determination of nitrogen and phosphorus in waste waters, their selection and optimization methods including mobile analytics. Experimental section is devoted to the abstraction of wastewater from selected wastewater treatment plants and their analysis methods including mobile analytics and comparing them with the presentation of their results. The conclusion is drawn evaluate the content of nitrogen and phosphorus in wastewater influent and effluent from wastewater treatment plants and compared the variation of these values during the one-month study and compared with published data.
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