National Repository of Grey Literature 4 records found  Search took 0.00 seconds. 
Study on potential applications of glutamic acid polymer
Čangelová, Katarína ; Skoumalová, Petra (referee) ; Obruča, Stanislav (advisor)
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.
Production, characterization and application of polymers of malic and glutamic acids
Čangelová, Katarína ; Kučera, Dan (referee) ; Obruča, Stanislav (advisor)
Subject of this bachelor thesis was study of biopolymers production using microorganisms. Polymer of malic acid was produced by Aureobasidium pullulans, a yeast-like fungus. Biosynthesis of polymer of glutamic acid was carried out by Bacillus licheniformis bacterium. Particular polymers, their microbial producers and possible application in different areas are characterised in the theoretical part of the thesis. Through experiments, the effect of various conditions on cell growth and production of these polymers was studied. Cultivation conditions were optimised in terms of polymers production. Subsequently, waste substrates - whey and poultry feathers were used. Microbially-produced polymer of malic acid was hydrolysed with 2 M sulfuric acid. Concentration of malic acid was analysed by IEC with a conductivity detector. Concentration of polymer of glutamic acid was determined by a spectrophotometric method using CTAB.
Study on potential applications of glutamic acid polymer
Čangelová, Katarína ; Skoumalová, Petra (referee) ; Obruča, Stanislav (advisor)
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.
Production, characterization and application of polymers of malic and glutamic acids
Čangelová, Katarína ; Kučera, Dan (referee) ; Obruča, Stanislav (advisor)
Subject of this bachelor thesis was study of biopolymers production using microorganisms. Polymer of malic acid was produced by Aureobasidium pullulans, a yeast-like fungus. Biosynthesis of polymer of glutamic acid was carried out by Bacillus licheniformis bacterium. Particular polymers, their microbial producers and possible application in different areas are characterised in the theoretical part of the thesis. Through experiments, the effect of various conditions on cell growth and production of these polymers was studied. Cultivation conditions were optimised in terms of polymers production. Subsequently, waste substrates - whey and poultry feathers were used. Microbially-produced polymer of malic acid was hydrolysed with 2 M sulfuric acid. Concentration of malic acid was analysed by IEC with a conductivity detector. Concentration of polymer of glutamic acid was determined by a spectrophotometric method using CTAB.

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