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Adsorption of microbial cells on model biological surfaces
Mikušová, Janka ; Krouská, Jitka (referee) ; Sedláček, Petr (advisor)
The aim of this bachelor thesis is creating sorption surface suitable for studying adsorption bacterial strain Lactobacillus rhamnosus, as representative probiotic bacterial strain. Included in the experimental part of this thesis was the process of creating sorption surface, according to the designed and especially optimized method. Optimization method comprised of preparing sorbent with sorption surface including mucin, on which was the bacterial strain Lactobacillus rhamnosus bound to, using specific interaction. UV-VIS spectrophotometry was utilized in the optimization of the sorption surface preparation for monitoring losses of mucin in solution that happens during the bondation on used substrate. Designed sorption surfaces were subjected to various physical-chemical analyses, which roles were displaying and characterisation of surface and confirming the presence of mucin. One of the major components, in the process of observing and characterization of changes in surface structure of the sorption surface, was infrared spectroscopy with Fourier transformation. Scanning electron microscopy was used for more detailed observation of the surface structure, created by adhesive interactions, which participate in probiotic bacteria adhesion. Finally, the created surfaces were used in pilot experiment, during which, the kinetics in growing bacterial culture with and without the presence of sorbent using microcalorimetry were observed. Designed sorbent appears to be a suitable mediator for detailed characterisation of bacterial adhesion, which is the first step in creating bacterial biofilm.
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Study of ozone decomposition on solid surfaces
Krejsková, Eliška ; Stančík, Jiří (referee) ; Kozáková, Zdenka (advisor)
This bachelor’s thesis is focused on the study of ozone decomposition which occurs during its contact with solid surfaces. The aim is to find out which material causes the lowest ozone decomposition and that is why it is the most suitable material for pipelines used for ozone transportation from a place of production to a place of application. In the theoretical part important properties of ozone, possibilities of its production, methods of ozone determination and relation of ozone to different solid surfaces were described. In the experimental part there was investigated how much ozone is decomposed by five commonly available metal materials (stainless steel, yellow brass, copper, aluminium and iron). Measurements were realized in the glass tube (Liebig condenser). Hollow pipes made of particular material were inserted into this tube. Ozone passed through this glass tube and ozone concentration was determined on its output by two methods: the iodometric titration and spectrophotometry. Several series were measured and compared by different set-up conditions like reaction time, experimental parameters (flow rate of air, input power of the ozone generator) and two types of gas – technical and synthetic air (because moisture contained in technical air can cause ozone decomposition) were used. The most suitable materials – stainless steel and aluminium were determined according to gained results.
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Application of spectrophotometers
Klimešová, Marie ; Čmiel, Vratislav (referee) ; Kolář, Radim (advisor)
The work deals with the important analytical method - spectrometry. It is based on measurement of absorption of radiation in a wavelength range. On this principle can determine the absorbance and transmittance of the measured samples. The thesis also describes events related to the excitation of molecules. These include absorption, vibrational relaxation, internal conversion, inter-system crossing, fluorescence, phosphorescence and delayed fluorescence. The practical part includes three experimental measurements. The first measurement is the concentrations of potassium permanganate solution. In a second experiment, verifying the validity of Lambert-Beer law. In the third experiment, the fluorescence measurement of fluorescein and detection of fluorophore concentration dependence on fluorescence intensity. Measurement is performed in an environment SpectraSuite with the use of school spectrometers USB2000 + and USB650 Red Tide.
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Characterization of adsorption properties of probiotic bacteria
Černá, Klára ; Sedláček, Petr (referee) ; Obruča, Stanislav (advisor)
The aim of the diploma thesis is to characterize the adsorption properties of probiotic bacteria. Characterization was performed using of designed and optimized spectrophotometric method of determination of adhesion of probiotic bacteria to mucin as the main viscoelastic component of mucus. In order to provide a more detailed description of the adhesion interactions involved in the adhesion of probiotic bacteria to mucin, the viability of selected probiotic bacterial strains Lactobacillus rhamnosus CCM 1825, Lactobacillus plantarum CCM 7039, Lactobacillus delbrueckii subsp. bulgaricus CCM 7190, Lactobacillus acidophilus CCM 4833, Lactobacillus casei CCM 4798, Bifidobacterium breve CCM 7825, Bacillus coagulans CCM 2658 and a potential probiotic strain of Lactobacillus zeae CCM 7069. Moreover, bacterial adhesion to carbohydrates was also determined for all the bacteria tested. The last proposed and optimized technique was dynamic and electrophoretic light scattering characterizing surface properties such as -potential, average size distribution and isoelectric point. From this method, information was obtained on aggregation of bacterial cells and on electrostatic interactions. The combination of these methods was used as a complex tool to characterize adhesion of the tested bacterial cultures as a very specific, sensitive and key parameter of a successful probiotic microorganism that is influence by the multiple effects.
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Determination of selected chemical parameters of fruit of new currant varieties
Pelikánová, Blanka ; Diviš, Pavel (referee) ; Vespalcová, Milena (advisor)
Presented diploma thesis is dedicated to the determination of selected chemical parameters of fruits of new currant varieties. The theoretical part is focused on the characteristics of currant, the biologically active substances of its fruits and also the utilization of current in the food industry. Further part of the theory deals with the main chemical parameters which were examined: polyphenols, anthocyanins, ascorbic acid and antioxidant activity. In the practical part there were determined selected chemical parameters in six white, twelve red and thirteen black varieties of currant. Anthocyanins and polyphenols have been determined spectrophotometrically. The content of ascorbic acid in selected varieties of currant was determined by HPLC. As a technique for the determinationof the antioxidant activity was selected the method of free radical DPPH.
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Transport properties of hyaluronan-based hydrogel systems
Káčeríková, Martina ; Smilek, Jiří (referee) ; Klučáková, Martina (advisor)
This bachelor thesis deals with the study of trasport properties of hydrogels, that were prepared by interaction of hyaluronan with karbethopendecinium bromide (Septonex), as a surfactant. Nile red is a fluorescent probe to determine the ability of the system to absorb or to release the substance. All the hydrogels were prepared by the „wet“ way, where the solutions of hyaluronan and surfactant were prepared first. Nile red was prepared in the solution of tenzide, which after the mixing with hyaluronan produced colorful gels. By the spectrophotometric measurement, the absorbance of supernatants were observed. The absorbance was measured in original but also in changed supernatatns after 24, 72 and 168 hours.
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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 cell and its survival in the environment. Furthermore, light, light’s behavior and optical spectral analysis in some methods is 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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Generation of ozone by photochemical processes in O2 and admixtures
Tomečková, Klára ; Blahová, Lucie (referee) ; Mazánková, Věra (advisor)
Ozone is a toxic gas with the fatal impact to living organisms at high concentrations. Therefore, this gas is useful in sterilization in many cases. The subject of this work is the generation of ozone using various methods and determination of its concentration. Then the generated ozone can be used in ozone therapy. The theoretical part deals with properties and use of ozone. In addition, information gathering connected to ozone was performed. It was about methods of ozone generation and subsequently about the diagnostics determine of ozone concentration. In the experimental part the ozone generation and determination of its concentration was performed using spectrophotometric method and iodometric titration. The ozone concentration in the air was also measured over the long term using the Schönbein method.
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