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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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Analysis of biologically active substances from medical mushrooms
Macháčková, Mirka ; Bendová, Agáta (referee) ; Hoová, Julie (advisor)
This bachelor thesis deals with the benefits of mushrooms for the human body and with the important substances that are contained in them and give them properties that cannot be found in any other natural food component in such a complex design. Specifically, the mushrooms discussed in the thesis belong to rare species of mushrooms, not only because of their rare occurrence in nature, but mainly because of their unmistakable positive properties. In the theoretical part of the thesis, the basic characteristics of fungi, structural features and basic division were described. Further, the theoretical part discusses the characteristics of individual rare mushrooms that were selected for further observation. It deals mainly with their occurrence, positive impact on the human body and their practical use. This section also deals with the chemical composition of mushrooms, specifically the contained and immunologically active substances. Last but not least, the theoretical part describes important microorganisms that were used in measuring antimicrobial activity in the practical part of this work. The practical part of the thesis was devoted to the preparation of mushroom extracts from reishi, shiitake, oyster mushroom and Judas ear mushrooms using three different solvents. It optimizes methods for the determination of nutritionally important substances by selecting appropriate solvents that were able to positively influence the yield when determining the mushroom content. It is also engaged in testing antioxidant activity, determination of content and antimicrobial activity. Based on these measurements, it was proved that all the above-mentioned active substances are present in different concentrations in the mushrooms studied. Mushroom powders or their extracts can subsequently be used alone as dietary supplements or as an additive to foods with low nutritional value.
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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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The circulation of cobalt in the environment
Charuza, Martin ; Mládková, Zuzana (referee) ; Sommer, Lumír (advisor)
This bachelor thesis deals with importance of cobalt in the environment, especially as a component of B12 vitamin. Vitamin B12 is a complex, that is necessary for proper formation of blood corpuscules and DNA, except that affects many others procesess in the body. Cobalt forms many complex compounds, which are discussed in this work. The most common oxidation number in compounds are +II and +III. The second part describes spectrophotometric determination of cobalt with suitable reagents. There are a lot of spectrophotmetric reagents for cobalt determination in a sample. The most widely used spectrophotometric reagents for determination of cobalt are 4-(2-pyridylazo)resorcinol (PAR), 1-(2-pyridylazo)-2-naphtol (PAN), 2-(5-Brom-2-pyridylazo)-5-diethylaminophenol (5-Brom-PADAP), 4-(2-thiazolylazo)resorcinol (TAR) a 2-(2-thiazolylazo)-4-methoxyphenol (TAMP). All of theese reagents are heterocyclic azodyes. Cobalt is bonded on this azodyes by coordination covalent bond and forms stable complex.
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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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