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Study on potential applications of glutamic acid polymer
Čangelová, Katarína ; Skoumalová, Petra (oponent) ; Obruča, Stanislav (vedoucí práce)
The subject of the thesis is study of possible applications of isoform of glutamic acid polymer (-PGA). The theoretical part is focused on the properties of this biopolymer and potential applications in various areas. Producers and mechanisms of biosynthesis are also mentioned. In the experimental part, the polymer was firstly characterised by following methods: FT-IR spectroscopy, TGA, DSC and SEC-MALS. Its isoelectric point, antimicrobial activity and solubility in various solvents were also determined. The biopolymer was also precipitated by divalent cations and its interaction with oppositely charged CTAB surfactant was studied. The main experimental study was researching the effect of -PGA on viability of Saccharomyces cerevisiae and Lactobacillus rhamnosus under stress conditions by flow cytometry. The performed stresses included ethanol exposure, high temperature and freezing stress, in which its effects were compared to conventional cryoprotectants. The cells of the mentioned microorganisms were also stressed osmotically and exposed to model gastrointestinal juices - gastric, pancreatic and bile. The protective effects of -PGA on the cells were recorded in ethanol stress on Lactobacillus rhamnosus. Its excellent cryoprotection properties were confirmed and its protective effect of gastric juice exposure on Saccharomyces cerevisiae cells was also observed. At the end of the experimental part, -PGA/alginate beads suitable for encapsulation of probiotic bacteria and -PGA/chitosan nanoparticles for encapsulation of biologically active substances.
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Adsorption of microbial cells on model biological surfaces
Mikušová, Janka ; Krouská, Jitka (oponent) ; Sedláček, Petr (vedoucí práce)
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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Aktivní přípravky na bázi koji fermentace a extraktů z vzácných hub
Živná, Kristýna ; Dzurická, Lucia (oponent) ; Hoová, Julie (vedoucí práce)
Tato bakalářská práce se zabývá optimalizací kultivace růstu vzácné houby korálovce ježatého na obilných substrátech za účelem následné fermentace s přídavkem vybraného zástupce mléčné bakterie. Teoretická část je zaměřena na popis vzácné houby a používaných obilných substrátů a charakterizaci jejich aktivních látek. Dále se zabývá mléčnou fermentací a její využití. V experimentální části byla optimalizována příprava obilného substrátu pro kultivaci korálovce ježatého. Jako nejvhodnější byla zvolena metoda očkování obilného substrátu tekutým myceliem v kombinaci s plotnovým. V této kombinaci nedochází k zasychání substrátu a mycelium roste rovnoměrně z obou stran substrátu. Následně bylo pomocí spektrofotometrických metod charakterizováno složení obilného substrátu s narostlým myceliem (antioxidační aktivita, sacharidy, bílkoviny). Nakonec byla provedena koji fermentace substrátu s narostlým myceliem bez a s přídavkem mléčné bakterie. Mléčná bakterie přidala výživovou hodnotu do produktu. Byly charakterizovány produkty fermentace (antioxidační aktivita, sacharidy, bílkoviny), a byla stanovena viabilita bakterií.
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Study on potential applications of glutamic acid polymer
Čangelová, Katarína ; Skoumalová, Petra (oponent) ; Obruča, Stanislav (vedoucí práce)
The subject of the thesis is study of possible applications of isoform of glutamic acid polymer (-PGA). The theoretical part is focused on the properties of this biopolymer and potential applications in various areas. Producers and mechanisms of biosynthesis are also mentioned. In the experimental part, the polymer was firstly characterised by following methods: FT-IR spectroscopy, TGA, DSC and SEC-MALS. Its isoelectric point, antimicrobial activity and solubility in various solvents were also determined. The biopolymer was also precipitated by divalent cations and its interaction with oppositely charged CTAB surfactant was studied. The main experimental study was researching the effect of -PGA on viability of Saccharomyces cerevisiae and Lactobacillus rhamnosus under stress conditions by flow cytometry. The performed stresses included ethanol exposure, high temperature and freezing stress, in which its effects were compared to conventional cryoprotectants. The cells of the mentioned microorganisms were also stressed osmotically and exposed to model gastrointestinal juices - gastric, pancreatic and bile. The protective effects of -PGA on the cells were recorded in ethanol stress on Lactobacillus rhamnosus. Its excellent cryoprotection properties were confirmed and its protective effect of gastric juice exposure on Saccharomyces cerevisiae cells was also observed. At the end of the experimental part, -PGA/alginate beads suitable for encapsulation of probiotic bacteria and -PGA/chitosan nanoparticles for encapsulation of biologically active substances.
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Adsorption of microbial cells on model biological surfaces
Mikušová, Janka ; Krouská, Jitka (oponent) ; Sedláček, Petr (vedoucí práce)
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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Vliv různých forem glutathionu na kulturu Lactobacillus
Lacková, Zuzana
Glutathion jako jedna z významných thiolových sloučenin se vyskytuje téměř ve všech organismech. Podílí se na ochraně buněk proti oxidačnímu stresu a podporuje tak redoxní rovnováhu buněk. Podobné vlastnosti na organismus vykazuje i Lactobacillus rhamnosus, který je znám svými antioxidačními vlastnostmi a také působí příznivě proti oxidačnímu stresu. V práci byl hodnocen vliv GSH a GSSG o koncentracích 0, 3, 300 a 3000 uM na kulturu L. rhamnosus CCM 4185. Během hodnocení efektu využitím mikrobiologických a biochemických metod bylo zjištěno, že se zvyšující se koncentrací přídavku obou glutathionů dochází k poklesu obsahu glukózy a bílkovin v buňkách, což poukazuje jejich zvýšenou metabolickou aktivitu v přítomnosti glutathionu v extracelulárním prostoru. Vliv glutathionů na kulturu L. rhamnosus není negativní, v některých případech je vliv i lehce pozitivní.
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