Studium možných aplikací polymeru kyseliny glutamové
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Vysoké učení technické v Brně. Fakulta chemická
Abstract
Predmetom diplomovej práce je štúdium možných aplikácií izoformy polyméru kyseliny glutámovej (-PGA). Teoretická časť je zameraná na vlastnosti tohto biopolyméru a potenciálne aplikácie v rôznych oblastiach. Sú spomenutí aj jeho producenti a mechanizmus biosyntézy. V experimentálnej časti bol najskôr polymér charakterizovaný prostredníctvom nasledujúcich metód: FT-IR spektroskopia, TGA, DSC a SEC-MALS. Bol tiež zistený jeho izoelektrický bod, antimikrobiálna aktivita a rozpustnosť v rôznych rozpúšťadlách. Biopolymér bol tiež zrážaný divalentnými katiónmi a študovaná bola jeho interakcia s opačne nabitým surfaktantom CTAB. Hlavnou experimentálnou štúdiou bolo sledovanie vplyvu -PGA na viabilitu Saccharomyces cerevisiae a Lactobacillus rhamnosus pri stresových podmienkach pomocou prietokovej cytometrie. Vykonané stresy zahŕňali pôsobenie etanolu, teplotný stres s vysokou teplotou a mrazením, pri ktorom boli jeho účinky porovnané s konvenčnými kryoprotektantami. Bunky zmienených mikroorganizmov boli stresované taktiež osmoticky a boli vystavené modelovým gastrointestinálnym šťavám – žalúdočnej, pankreatickej a žlčovej. Ochranné účinky -PGA na bunky boli zaznamenané pri etanolovom strese na Lactobacillus rhamnosus. Potvrdené boli jeho vynikajúce kryoprotekčné vlastnosti a ochranný efekt mal aj na bunky Saccharomyces cerevisiae pri pôsobení žalúdočnej šťavy. Na záver experimentálnej časti boli pripravované častice -PGA/alginát vhodné pre enkapsuláciu probiotických baktérií a nanočastice -PGA/chitosan pre enkapsuláciu biologicky aktívnych látok.
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.
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.
Description
Keywords
polymér kyseliny glutámovej, -PGA, charakterizácia, aplikácie, prietoková cytometria, stres, protekčné účinky, Lactobacillus rhamnosus, Saccharomyces cerevisiae, kryoprotektant, simulované gastrointestinálne šťavy, -PGA/alginát perly, -PGA/chitosan nanočastice, glutamic acid polymer, -PGA, characterisation, applications, flow cytometry, stress, protective effects, Lactobacillus rhamnosus, Saccharomyces cerevisiae, cryoprotectant, simulated gastrointestinal juices, -PGA/alginate beads, -PGA/chitosan nanoparticles
Citation
ČANGELOVÁ, K. Studium možných aplikací polymeru kyseliny glutamové [online]. Brno: Vysoké učení technické v Brně. Fakulta chemická. 2019.
Document type
Document version
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Language of document
sk
Study field
Chemie pro medicínské aplikace
Comittee
prof. Ing. Miloslav Pekař, CSc. (předseda)
prof. RNDr. Ivana Márová, CSc. (místopředseda)
doc. Ing. Pavel Diviš, Ph.D. (člen)
doc. Ing. Petr Dzik, Ph.D. (člen)
doc. Ing. Stanislav Obruča, Ph.D. (člen)
prof. RNDr. Zbyněk Zdráhal, Dr. (člen)
Date of acceptance
2019-05-29
Defence
Dzik: Prosím o upřesnění postupu při enkapsulaci?Diviš: Lze g-PGA vyrobit i synteticky? Používá se tento postup? Jak seliší vlastnosti syntetického polymeru od biogenního?Pekař: Jaký byl stupeň hydrolýzy vašeho polymeru? Jaké bylo Ph vodných roztoků? Jakou metodiku jste použila pro posouzení rozpustnosti? Student prokázal výbornou orientaci v dané problematice a schopnost samostatné prezentace získaných výsledků.
Result of defence
práce byla úspěšně obhájena
Document licence
Standardní licenční smlouva - přístup k plnému textu bez omezení