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Utilization of Light Scattering for the Study on the Structural and Conformation Changes during the Interaction of Biopolymers
Dobiášová, Andrea ; Hurčíková, Andrea (referee) ; Kalina, Michal (advisor)
The aim of this bachelor thesis was to study structural and conformation changes during the interaction of biopolymers by ligth scattering methods. This study was focused on hyaluronic acid with two molecular weights 250 – 450 kDa and 1500 – 1750 kDa, on sodium alginate and dextran hydrochloride (DEAE). NaCl, CaCl2 and BSA were used as interacting agents. Simple physical-chemical methods, like UV-VIS spectrometry, dynamic and electrophoretic light scattering, were used in experimental part. The main used method for these purposes was size exclusion chromatography coupled with light scattering and viscosimetry detectors. The studied characteristics of experiment were molecular weight, gyration and hydrodynamic radius, zeta potential and coefficients of conformation and Mark-Howinks diagrams. Interactions have been proved between negatively charged polyelectrolytes and additives. NaCl practically did not interact with any polysaccharide, only increasing ionic strength. Positively charged dextran interacted only with the BSA, despite having the same charge.
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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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Utilization of Light Scattering for the Study on the Structural and Conformation Changes during the Interaction of Biopolymers
Dobiášová, Andrea ; Hurčíková, Andrea (referee) ; Kalina, Michal (advisor)
The aim of this bachelor thesis was to study structural and conformation changes during the interaction of biopolymers by ligth scattering methods. This study was focused on hyaluronic acid with two molecular weights 250 – 450 kDa and 1500 – 1750 kDa, on sodium alginate and dextran hydrochloride (DEAE). NaCl, CaCl2 and BSA were used as interacting agents. Simple physical-chemical methods, like UV-VIS spectrometry, dynamic and electrophoretic light scattering, were used in experimental part. The main used method for these purposes was size exclusion chromatography coupled with light scattering and viscosimetry detectors. The studied characteristics of experiment were molecular weight, gyration and hydrodynamic radius, zeta potential and coefficients of conformation and Mark-Howinks diagrams. Interactions have been proved between negatively charged polyelectrolytes and additives. NaCl practically did not interact with any polysaccharide, only increasing ionic strength. Positively charged dextran interacted only with the BSA, despite having the same charge.
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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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