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Characterization of antioxidative and antimicrobially active substances in some types of wood
Ďatko, Tomáš ; Hlaváček, Viliam (referee) ; Márová, Ivana (advisor)
The purpose of this bachelor thesis is to analyze antioxidant and antimicrobial active substances in woody plants. The theoretical part deals with characterization of these biologically active substances, the overview of selected types of woody plants and dividing of extraction techniques. Moreover, methods for determination antimicrobial activity were described. The experimental part is focused on preparation of bark extracts of birch, oak and willow using different solvents (water, methanol, ethanol, DMSO) at various parameters (time, temperature). The concentration of polyphenols, flavonoids, tannins and antioxidant activity was set by using spectrophotometrical method. Subsequently antimicrobial activity of extracts was tested against the three microorganisms: Micrococcus luteus, Serratia marcescens and Candida glabrata. The results show that the most antioxidant active substances are found in the willow bark and antimicrobial activity was showed very weakly in selected bark extracts.
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Study of bioactive compounds of fennel
Mierna, Jana ; Skoumalová, Petra (referee) ; Veselá, Mária (advisor)
The master´s thesis is focused on the study of biologically active compounds of fennel. The theoretical part describes basic characteristics of fennel and its chemical composition, further specifies plant´s biological active substances and antioxidants, also describes extraction techniques for obtaining these bioactive compounds, methods of their determination and verification of antimicrobial effect. In the experimental part were spectrophotometrically determined contents of polyphenols and flavonoids in the prepared extracts of fennel tea, whole and crush spice. On the basis of extraction curves, antioxidant activity and potential antimicrobial activity against the selected microorganisms Bacillus subtilis, Bacillus cereus, Serratia marcescens a Micrococcus luteus was determined in the samples with the highest values of the given bioactive substances. Among the all monitored extracts, the inhibitory effect was showed only by an aqueous extract of the fennel tea against the bacterial strain of Micrococcus luteus.
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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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Sea buckthorn – the source of natural compounds
Blašková, Daniela ; Vítová, Eva (referee) ; Veselá, Mária (advisor)
The main aim of the bachelor thesis was a research of common sea buckthorn, often denoted as "a plant of future". Botanic characteristics of the given bush, verification of biologically active substances and various concentration extract effects on selected kinds of microorganisms. In the theoretical part, the literature search is done, which discusses the characterization of the researched plant. The practical part deals with the application of selected methods of research, as follows: spectrophotometric determination of biologically active substances and microbiological verification of microbial activity on microorganisms, such as Bacillus subtilis, Serratia marcenscens and Micrococcus luteus. Considering the thesis results, it ensues that the given extracts do not show too great bacterial activity. Ex adverso, the extracts contain too big amount of determined active substances, in some cases.
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Study of properties and effect of some natural antimicrobial substances
Horňáková, Nikola ; Kostovová, Iveta (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on the testing of natural antimicrobial substances of plant origin, dealing with their characterisation, their effect against the microorganisms, optimization of antimicrobial testing and increasing of efficiency of their active compounds. Theoretical part of this thesis describes a characterisation of used natural species, their important properties, spectrophotometrical methods applied in determination of active compounds, opportunities of stabilization of natural substances and various techniques of antimicrobial testing. In experimental part 8 kinds of tea and non-tea plants (Pai Mu Tan, Formosa Gunpowder, Gunpowder Black, Honeybush, Lapacho, Aspalathus linearis and Paullinia cupana) were used and combined with 6 herbal species (Syzygium aromaticum, Urtica dioica, Hippophae rhamnoides, Matricaria recutita, Plantago lanceolata and cinnamon), extracted by different solvents (water, ethanol and dimethyl sulfoxide). In these extracts amount of antioxidants and effect to three bacterial cultures (Escherichia coli, Micrococcus luteus and Serratia marcescens) were determined. To improve antimicrobial, antioxidant activity and stability aqueous tea extracts were encapsulated into liposomal particles.
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Antimicrobial Activity Evaluation of Biocidal Surfaces with Resazurin Assay
Patakyová, Sylvia ; Viktorová,, Jitka (referee) ; Králová, Marcela (advisor)
This diploma thesis deals with the determination of antimicrobial activity of surfaces with biocidal effect using the resazurin test. The resazurin method of determination is a non-invasive colorimetric method with great potential for widespread use. However, its use so far has been limited as it is not included among standardized methods. The colorimetric method was used as a way to evaluate the effectiveness of immersion experiments using antimicrobial films and the bacterial strain Escherichia coli. The fluorescence intensity of the dye in the suspensions, which were affected by the individual foils, was captured by photographic recording and subsequently evaluated using image analysis. The measured and calculated values of the antimicrobial effect of three samples of active foils with different concentrations of the biocidal substance were compared with the results obtained in conditions with a smaller error rate (using plate-reader) and with the results obtained through a standardized method to demonstrate the relevance of the resazurin method and to assess the antimicrobial activity of studied surfaces.
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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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Study of bioactive compounds of fennel
Mierna, Jana ; Skoumalová, Petra (referee) ; Veselá, Mária (advisor)
The master´s thesis is focused on the study of biologically active compounds of fennel. The theoretical part describes basic characteristics of fennel and its chemical composition, further specifies plant´s biological active substances and antioxidants, also describes extraction techniques for obtaining these bioactive compounds, methods of their determination and verification of antimicrobial effect. In the experimental part were spectrophotometrically determined contents of polyphenols and flavonoids in the prepared extracts of fennel tea, whole and crush spice. On the basis of extraction curves, antioxidant activity and potential antimicrobial activity against the selected microorganisms Bacillus subtilis, Bacillus cereus, Serratia marcescens a Micrococcus luteus was determined in the samples with the highest values of the given bioactive substances. Among the all monitored extracts, the inhibitory effect was showed only by an aqueous extract of the fennel tea against the bacterial strain of Micrococcus luteus.
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Characterization of antioxidative and antimicrobially active substances in some types of wood
Ďatko, Tomáš ; Hlaváček, Viliam (referee) ; Márová, Ivana (advisor)
The purpose of this bachelor thesis is to analyze antioxidant and antimicrobial active substances in woody plants. The theoretical part deals with characterization of these biologically active substances, the overview of selected types of woody plants and dividing of extraction techniques. Moreover, methods for determination antimicrobial activity were described. The experimental part is focused on preparation of bark extracts of birch, oak and willow using different solvents (water, methanol, ethanol, DMSO) at various parameters (time, temperature). The concentration of polyphenols, flavonoids, tannins and antioxidant activity was set by using spectrophotometrical method. Subsequently antimicrobial activity of extracts was tested against the three microorganisms: Micrococcus luteus, Serratia marcescens and Candida glabrata. The results show that the most antioxidant active substances are found in the willow bark and antimicrobial activity was showed very weakly in selected bark extracts.
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Sea buckthorn – the source of natural compounds
Blašková, Daniela ; Vítová, Eva (referee) ; Veselá, Mária (advisor)
The main aim of the bachelor thesis was a research of common sea buckthorn, often denoted as "a plant of future". Botanic characteristics of the given bush, verification of biologically active substances and various concentration extract effects on selected kinds of microorganisms. In the theoretical part, the literature search is done, which discusses the characterization of the researched plant. The practical part deals with the application of selected methods of research, as follows: spectrophotometric determination of biologically active substances and microbiological verification of microbial activity on microorganisms, such as Bacillus subtilis, Serratia marcenscens and Micrococcus luteus. Considering the thesis results, it ensues that the given extracts do not show too great bacterial activity. Ex adverso, the extracts contain too big amount of determined active substances, in some cases.
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