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Study of electrophotocatalytic water disinfenction
Cisáriková, Barbora ; Zita, Jiří (referee) ; Veselá, Mária (advisor)
This bachelor thesis was focused on the photocatalytic disinfection of water with titanium dioxide applied to the working electrode. The experiment was conducted under normal conditions, with the application of UV-radiation with intensity of 40 W/m2 and with UV radiation and of 1 V electrical voltage at the same time. Each part of the experiment was run for 60 and 120 minutes. The microbicidal effect was monitored on Escherichia coli bacteria.
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Kinetics of electrophotocatalytic water disinfection
Štefancová, Eva ; Zita, Jiří (referee) ; Veselá, Mária (advisor)
In this work, electrophotocatalytic disinfection on selected microorganisms was verified. The electrophotocatalytic system allows the application of electrical bias to the photoanode coated with a titanium dioxide layer. The disinfecting effect was observed on E.coli and C.glabrata in aqueous solution. The effect of radiation intensity on electrophotocatalysis and selected optimal conditions for further experiments was observed in the E. coli organism. Photocatalytic disinfection was carried out under suitable conditions on C.glabrata yeast and the effect of sodium sulfate electrolyte on electrophotocatalytic disinfection was observed in this case.
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Antimicrobial Activity Evaluation of Biocidal Surfaces with Resazurin Assay
Patakyová, Sylvia ; Viktorová,, Jitka (referee) ; Králová, Marcela (advisor)
This diploma thesis deals with the determination of antimicrobial activity of surfaces with biocidal effect using the resazurin test. The resazurin method of determination is a non-invasive colorimetric method with great potential for widespread use. However, its use so far has been limited as it is not included among standardized methods. The colorimetric method was used as a way to evaluate the effectiveness of immersion experiments using antimicrobial films and the bacterial strain Escherichia coli. The fluorescence intensity of the dye in the suspensions, which were affected by the individual foils, was captured by photographic recording and subsequently evaluated using image analysis. The measured and calculated values of the antimicrobial effect of three samples of active foils with different concentrations of the biocidal substance were compared with the results obtained in conditions with a smaller error rate (using plate-reader) and with the results obtained through a standardized method to demonstrate the relevance of the resazurin method and to assess the antimicrobial activity of studied surfaces.
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The Effect of temperature treatment TiO2 nanoparticles on antibacterial properties
Bytesnikova, Z. ; Valeckova, V. ; Švec, P. ; Richtera, L. ; Šmerková, K. ; Vítek, Petr ; Adam, V.
The synthesis of TiO2 nanoparticles (NPs) under various temperature treatments was described and TiO2 NPs was subsequently tested as an antibacterial agent. Scanning electron microscopy (SEM), Raman spectroscopy, Dynamic light scattering (DLS) were used to confirm structure of TiO2 NPs and detect differences between individual batches treated with different temperature. Antibacterial properties were tested on Escherichia coli (E. coli). TiO2 NPs as photocatalyst was incubated with bacterial cells under ambient light. Changes in temperature treatment can affect diameter size and crystal structure of TiO2 NPs as well as its antibacterial properties.
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Role of bacteria and mucosal immune system and their interaction in the pathogenesis of inflammatory bowel disease
Du, Zhengyu ; Hudcovic, Tomáš (advisor) ; Prokešová, Ludmila (referee) ; Kamanová, Jana (referee)
Although the etiology and pathogenesis of inflammatory bowel disease (IBD) is not fully understood, it is generally accepted that the inflammation results from aberrant immune responses to antigens of gut microbiota in genetically susceptible individuals (Sartor et al., 2006). Alteration in intestinal microbiota has been found in IBD patients with increased abundance of certain bacteria and decreased abundance of others. Due to the complexity of the disease, multifaceted interactions between genetic factors, host immune response, gut microbiota and environment factors need to be taken into account. In this thesis, the pathogenesis of IBD was first reviewed in respect with the four factors mentioned above. Then we concentrated on the interaction between IBD-associated bacteria and mucosal immune system. We investigated the ability of mucosal-associated bacteria (MAB) from IBD patients to induce spontaneous colitis in germ-free (GF) mice and the impact of those bacteria on the development of dextran sulfate sodium (DSS)-colitis. Together with the analysis of the composition of gut microbiota of MAB colonized mice, we demonstrated the potential deleterious microbes were able to increase the susceptibility to DSS-colitis once they found a suitable niche. We revealed the mechanism of an E.coli strain...
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Kinetics of electrophotocatalytic water disinfection
Štefancová, Eva ; Zita, Jiří (referee) ; Veselá, Mária (advisor)
In this work, electrophotocatalytic disinfection on selected microorganisms was verified. The electrophotocatalytic system allows the application of electrical bias to the photoanode coated with a titanium dioxide layer. The disinfecting effect was observed on E.coli and C.glabrata in aqueous solution. The effect of radiation intensity on electrophotocatalysis and selected optimal conditions for further experiments was observed in the E. coli organism. Photocatalytic disinfection was carried out under suitable conditions on C.glabrata yeast and the effect of sodium sulfate electrolyte on electrophotocatalytic disinfection was observed in this case.
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Study of electrophotocatalytic water disinfenction
Cisáriková, Barbora ; Zita, Jiří (referee) ; Veselá, Mária (advisor)
This bachelor thesis was focused on the photocatalytic disinfection of water with titanium dioxide applied to the working electrode. The experiment was conducted under normal conditions, with the application of UV-radiation with intensity of 40 W/m2 and with UV radiation and of 1 V electrical voltage at the same time. Each part of the experiment was run for 60 and 120 minutes. The microbicidal effect was monitored on Escherichia coli bacteria.
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Analysis og gene expression in prokaryotic and eukaryotic model organisms by proteomic gel-based separation tools
Petráčková, Denisa ; Weiser, Jaroslav (advisor) ; Nešvera, Jan (referee) ; Stulík, Jiří (referee)
This PhD thesis showed the applicability of a gel-based proteomic separation tool, 2-D electrophoresis in three independent projects. Supplemented with results obtained using different techniques the proteomic studies enabled a global imaging of proteoms in the studied biological systems. Comparing total proteoms of E. coli 61 protein changes were identified and connected with the development of the bacterial population in the presence of an antibiotic compound, erythromycin. This classic proteomic approach included sample extraction, optimization of its 2D separation followed by 2D gel analysis and protein identification by MS methods. A disadvantage of this work was an enourmously large amount of data to be analyzed by computer analysis. For the study of membrane proteom of B. subtilis during a pH induced stress, on the other hand, a modification of isolation techniques for membrane and membrane associated proteins was required first to improve the subsequent protein separation by 2-D electrophoresis. The optimalization of protein extraction included changes in detergents used for protein solubilization and a prolongation of time periods in the protein solubilization protocol. 5 relevant protein changes were then described that play a role in the bacterial response to pH stress. The proteins were...
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Role of bacteria and mucosal immune system and their interaction in the pathogenesis of inflammatory bowel disease
Du, Zhengyu ; Hudcovic, Tomáš (advisor) ; Prokešová, Ludmila (referee) ; Kamanová, Jana (referee)
Although the etiology and pathogenesis of inflammatory bowel disease (IBD) is not fully understood, it is generally accepted that the inflammation results from aberrant immune responses to antigens of gut microbiota in genetically susceptible individuals (Sartor et al., 2006). Alteration in intestinal microbiota has been found in IBD patients with increased abundance of certain bacteria and decreased abundance of others. Due to the complexity of the disease, multifaceted interactions between genetic factors, host immune response, gut microbiota and environment factors need to be taken into account. In this thesis, the pathogenesis of IBD was first reviewed in respect with the four factors mentioned above. Then we concentrated on the interaction between IBD-associated bacteria and mucosal immune system. We investigated the ability of mucosal-associated bacteria (MAB) from IBD patients to induce spontaneous colitis in germ-free (GF) mice and the impact of those bacteria on the development of dextran sulfate sodium (DSS)-colitis. Together with the analysis of the composition of gut microbiota of MAB colonized mice, we demonstrated the potential deleterious microbes were able to increase the susceptibility to DSS-colitis once they found a suitable niche. We revealed the mechanism of an E.coli strain...
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Role of UV radiation, solution conductivity and pulse repetition frequency in the bactericidal effects during pulse corona discharge in water
Špetlíková, E. ; Janda, V. ; Lukeš, Petr ; Člupek, Martin
Inactivation of bacteria Escherichia coli and Enterococcus faecalis by the pulsed corona discharge in liquid phase has been investigated. The reactor with point to plate geometry of electrodes was used for generation of the discharge in liquid phase. The effects of the solution conductivity and the pulse repetition frequency on the bacterial inactivation have been determined. Better efficiency of inactivation was observed for both types of bacteria with the increasing solution conductivity and the pulse repetition frequency since E. faecalis was more sensitive to these changes then E. coli. The role of UV radiation emitted by the electrical discharge in the overall bacterial efficiency was evaluated in dependence on the solution conductivity using UV light transparent spectrometric cell. It was determined that UV radiation contributes about 40% to the overall inactivation of bacteria by the discharge.
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