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Use and application of natural antimicrobial substances
Dzurická, Lucia ; Byrtusová, Dana (referee) ; Skoumalová, Petra (advisor)
The presented bachelor thesis is focused on the study of antimicrobial activity of plant substances in combination with bacteriocins and the possibility of creating new encapsulated form of supplement which could be used in food and cosmetic products. 5 plant materials were selected: acerola, cinnamon, cloves, orange peel and yacon syrup. Nisin was chosen as the most suitable bacteriocin. In the theoretical part the components with antimicrobial and antioxidant activity are described, such as the materials of plants and animal origin used in this work. Also the possibility of increasing the antimicrobial effect and possible use of natural antimicrobial substances were described. In experimental part, the aqueous extracts of selected plant materials were firstly spectrophotometrically characterized for the content of total polyphenols, flavonoids and antioxidants. Selected substances were encapsulated into liposomes and subsequently preparation of liposomes coated with chitosan was optimized. The particles were tested for size, short and long term stability, encapsulation efficiency and antioxidant activity. Furthermore, the antimicrobial activities of selected components in nonencapsulated and encapsulated form were observed against four strains of microorganisms (Escherichia coli, Micrococcus luteus, Serratia marcescens and Candida glabrata). Also the expected synergisms of the antimicrobial effects of extracts in combination with nisin and prepared particles were observed.
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Combined preparatives with encapsulated antimicrobial component
Kneblová, Kateřina ; Bendová, Agáta (referee) ; Márová, Ivana (advisor)
The presented bachelor thesis deals with the preparation and characterization of liposome nanoparticles that have been functionalized by the active substance and subsequently tested for their synergistic effect against microorganisms. In the theoretical part, a research focused on an overview of antimicrobials agents and on encapsulation techniques. In the experimental part, the method of sonification was used to prepare liposomes. Natural and synthetic antimicrobial substances were encapsulated into the particles. The size, stability, encapsulation efficiency, antioxidant and antimicrobial activity were determined for the liposomes that were prepared. Antimicrobial activity was tested on the gram-negative strain Esterichia coli, the gram-positive bacteria Micrococcus luteus, and one fungual strains Candida glabrata. Subsequently, a synergistic effect of the active substances was observed, which was demonstrated both when combining a synthetic active substance with a natural one and when combining two natural active substances. The synergistic effect of the encapsulated substances was observed after a longer period of time than that of the synergy of the pure active substrances. Which could find its application in the pharmaceutical industry, in drug delivery, or in the food industry in preservation processes.
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Use and application of natural antimicrobial substances
Dzurická, Lucia ; Byrtusová, Dana (referee) ; Skoumalová, Petra (advisor)
The presented bachelor thesis is focused on the study of antimicrobial activity of plant substances in combination with bacteriocins and the possibility of creating new encapsulated form of supplement which could be used in food and cosmetic products. 5 plant materials were selected: acerola, cinnamon, cloves, orange peel and yacon syrup. Nisin was chosen as the most suitable bacteriocin. In the theoretical part the components with antimicrobial and antioxidant activity are described, such as the materials of plants and animal origin used in this work. Also the possibility of increasing the antimicrobial effect and possible use of natural antimicrobial substances were described. In experimental part, the aqueous extracts of selected plant materials were firstly spectrophotometrically characterized for the content of total polyphenols, flavonoids and antioxidants. Selected substances were encapsulated into liposomes and subsequently preparation of liposomes coated with chitosan was optimized. The particles were tested for size, short and long term stability, encapsulation efficiency and antioxidant activity. Furthermore, the antimicrobial activities of selected components in nonencapsulated and encapsulated form were observed against four strains of microorganisms (Escherichia coli, Micrococcus luteus, Serratia marcescens and Candida glabrata). Also the expected synergisms of the antimicrobial effects of extracts in combination with nisin and prepared particles were observed.
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Synergism of entomopathogenic nematodes and entomopathogenic fungi
ŠILLEROVÁ, Tereza
The potential synergism between chosen species of entomopathogenic nematodes (Steinernema arenarium, Steinernema feltiae) and entomopathogenic fungi (Beauveria bassiana, Isaria fumosorosea, Lecanicillium lecanii) is investigated in this study. It is theoretically possible to expect increasing of their efficiency at the collective introduction into environment. Creating of uniform laboratory method which will be possible to use at the research of this interaction system is a part of this study.
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