|
|
Antimicrobial activity assessment of photoactive surfaces by dynamic method
Smelik, Adam ; Veselá, Mária (referee) ; Králová, Marcela (advisor)
This bachelor’s thesis deals with the assessment of the antimicrobial activity of photoactive surfaces by a dynamic method using a modified resazurin test. The resazurin test utilizes the irreversible conversion of resazurin to resorufin when metabolized by bacteria, which is characterized by a change in color and fluorescence intensity when observed. In this project, the resazurin test is used to evaluate the antibacterial effect of foils with a photoactive layer, on which a suspension containing Escherichia coli is applied. The antimicrobial activity of the foils was assessed by means of the calibration curve created for this species, and ways to optimize the method chosen by us were determined.
|
|
|
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.
|
|
|
Quality of drink water in Moravian-Silesian region
Diblíková, Michaela ; Navrátilová, Jana (referee) ; Omelková, Jiřina (advisor)
The objective of this work was determination of quality of waters made and spent in Moravskoslezský region by methods using Morava a. s laboratory. At interval from 2005 to 2006 was provided by the statistic analysis of accoplishments, that the maximum of pollution is microbial origin firstly by bacteries of Enterobacteriaceae tribe (coliform bacteries a E. coli). Chemical pollution was mainly provided by amonia ionts and by nitrates. It can may be contamination effect of inside or surface flows by fertilizers or septic tank wastes infiltrative.
|
|
|
Characterization of specific proteins form selected animal products.
Janhuba, Filip ; Obruča, Stanislav (referee) ; Márová, Ivana (advisor)
The master's thesis is focused on study of specific protective proteins from animal products. Two different types of antimicrobial egg white proteins were studied in detail - antimicrobial protein ovotransferrin (conalbumin) and enzyme lysozyme. Ovotransferrin belongs to transferrin group of proteins and exhibits activities similar to milk protective protein lactoferrin. The main effects of ovotransferrin are antiviral, anticancer and immunomodulatory. Antimicrobial activity of ovotransferrin based on the possibility to bind iron is still a subject of interest. For comparison the second egg protein lysozyme (N-acetyl muramidglycan hydrolase) was used. Lysozyme is a hydrolytic enzyme which primary attack cell wall of bacteria. In the theoretical part of the thesis an overview of the specific antimicrobial proteins in selected animal products was introduced mainly focused on ovotransferrin and lysozyme. The experimental part of this work was focused on optimization of methods for the determination of antimicrobial activity, protein concentration and purity. For quantitative analysis of total proteins, optimized Hartree – Lowry spectrophotometric method was used. For the determination of molecular weight and purity SDS-PAGE was used and stained by Coomassie Brilliant Blue G250 and silver. In experimental part the real sample of egg white was compared with samples of lyophilized antimicrobial proteins and therapeutical pills supplied by industrial partner. Protein composition and purity of these preparative has been determined. Antimicrobial activity of ovotransferrin was studied on cultures of G+ bacterium Bacillus subtilis and for comparison on G– E. coli. Ovotransferrin showed antimicrobial effect only at very high concentrations of about 75 mg/ml (Bacillus subtilis) and 50 mg/ml (E coli) even with addition of high amount (100 mM) of hydrogen carbonate ions. The inhibitory effect was most evident in liquid media. On the other hand, lysozyme exhibited significant inhibitory activity from 0.3 mg/ml on gram positive bacteria. Inhibitory effect on E. coli was not observed. Another part of study was focused on isolation of ovotransferrin from egg white using gel permeation chromatography on Sephadex G100. As mobile phases 0.1 M phosphate buffer and 0.05 M Tris-HCl buffer were tested. By SDS-PAGE the purity of ovotransferin comparing to standard was evaluated. Finally, the encapsulation of ovotransferrin and lysozyme was tested. Ovotransferrin and lysozyme was encapsulated into liposome and chitosan particles. Particles stability, distribution and average size distribution were studied by dynamic light scattering and zeta potential measurement. The stability of particles in the model physiological conditions was studied too.
|
|
|
Production of human milk oligosaccharides in the cell factory of E. coli
Havrdová, Jana ; Bojarová, Pavla (advisor) ; Smrček, Stanislav (referee)
Human milk oligosaccharides (HMOs) are among the most abundant components of human breast milk and are essential for the development of neonatal health. It is very challenging to isolate these oligosaccharides from animal milk, especially the less abundant ones. Therefore, different approaches are to be sought after. Chemical and enzymatic syntheses of these compounds are labor-intensive, and expensive affording low yields. A newly adopted approach to HMO synthesis is through bac- terial cell factories, in which genetically engineered bacterial strains can use cheap carbohydrate substrates and convert them into specific oligosaccharides. The aim of this thesis is to examine the feasibility of using selected bacterial strain (E. coli) for the production of HMOs. With lactose as a glycan substrate, the bacterial host has to be β-galactosidase deficient, otherwise, the substrate would be degraded. In order to generate higher lactose intake in the cell, a crp gene that encodes for the positive transcriptional regulator (Catabolite Activator Protein - CAP) can be incorporated into the host organism. The cloned plasmid - pRSFDuet- 1-crp was used for the transformation of into the selected bacterial strain. Lactose from the cells was purified by gel chromatography and the influence of CAP over expression...
|
|
|
Production and characterization of novel aryl sulfotransferases and their use in bioanalytics
Petránková, Barbora ; Bojarová, Pavla (advisor) ; Křížek, Tomáš (referee)
Polyphenols are the most common natural substances found in food. The largest group is represented by flavonoids, phenolic acids and catechols. Polyphenols are metabolized in the body during the biotransformation phase II, they can be sulfated, glucuronylated or methylated. To study biotransformation, it is necessary to have defined standards. Sulfated polyphenols can be prepared by enzymatic sulfation, which needs much milder reaction conditions compared to chemical sulfation. Prokaryotic sulfotransferases use 3'-phosphoadenosine-5'-phosphosulfate (PAPS) as a sulfate donor for sulfation, which is very expensive and difficult to regenerate. An alternative is the group of bacterial aryl sulfotransferases (EC 2.8.2.22), which catalyze the transfer of a sulfate group from a phenolic donor to a phenolic acceptor. Two bacterial aryl sulfotransferases from Desulfitobacterium hafniense and Escherichia coli have been described in the literature so far. The present thesis deals with the production, purification and biochemical characterization of two new bacterial aryl-sulfotransferases from Desulfosporosinus sp. HMP52 and Salmonella bongori. The enzymes were heterologously expressed in E. coli and purified by affinity chromatography. Their pH and temperature optimum, stability in organic solvents and...
|
|
| |
|
|
Production and characterization of galectin-3 mutant
Dubanych, Yurii ; Vaněk, Ondřej (advisor) ; Ječmen, Tomáš (referee)
Natural killer cells are large granular lymphocytes of innate immunity that are characterized by the ability to kill cancer and virus-damaged cells without prior activation. Cytotoxic functions of NK cells are regulated on the one hand through surface receptors recognizing MHC-I molecules, on the other hand by the presence of a set of activating and inhibitory receptors that are under normal conditions in balance with each other. Therefore, the fate of the target cell depends not only on the expression of MHC-I, but also on the expression of ligands that activate NK cell receptors. One of the activating receptors of NK cells is NKp30. Three specific cellular ligands have been discovered for NKp30: human BCL-2-associated athanogen 6 (BAG-6, also known as BAT3), tumour antigen B7-H6, and the newly discovered ligand galectin-3. All these ligands are often expressed by cancer cells, where BAG-6 and Gal-3 inhibit NK cell functions, which may be a mechanism for tumour escape from the immune system. Therefore, Gal-3 is a new potential drug target that, by inhibiting Gal-3, can help the immune system defend itself against malignantly transformed cells. This bachelor's thesis includes the verification of the effect of the Cys173 - Ser173 mutation in the carbohydrate recognition domain of galectin-3 on the...
|
|
|
Možnosti přežívání a množení patogenních a nepatogenních mikroorganismů v cukrářských výrobcích
Šrubařová, Monika
This master thesis is focusing on analysis of two kinds of confectionary products: nutty and lemon balls. The samples were analysed and they determinate the numbers of total count of bacteria, number of S. aureus, yeast and microscopic fungi, coliforms bacteria and E. coli, detection of Salmonella spp. and Listeria monocytogenes. Furthermore, S. aureus (strain CCM 5974) was inoculated in the samples. These samples determinate the number of S. aureus and possibility of the production an enterotoxins of S. aureus. Staphylococcal enterotoxin was detected with the reverse passive latex agglutination (RPLA). The result of determination is that the numbers of total count of bacteria influence of storage period the number was reduced (p<0,05). Statistical differences were not found between the nutty and the lemon balls (p>0,05). During the first and the second analysis was found growth of yeast and microscopic fungi in the nutty balls. In the lemon balls was found a growth of yeast and microscopically fungi during the first analyses and in one sample only. Also the number of bacteria was reduced with S. aureus (p<0,05). There were not found any statistical differences between the nutty and the lemon balls (p>0,05). The number of E. coli was not found in any our samples. The coliform bacterium was found only with the first and the second analysis in the nutty samples. In the lemon samples the coliform bacterium was found only in the first analysis. During the first detection of Salmonella spp. were found four colonies of this bacterium in the nutty samples. Colonies of Listeria monocytogenes were not detected in any of these samples. Microbiological analysis of inoculated sample confirms that our confectionary products are not suitable for growth of pathogenic microorganism S. aureus. It also proves that between the nutty and the lemon samples were no statistical difference (p>0,05). During the inoculation was proven that S. aureus (CCM 5974) with concentration 1,2.105 CFU.g-1 is capable to form in products enterotoxins, which stays in products in contrast with S. aureus, after a certain period of time.
|
|
|
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.
|
guest ::
