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Ion-selective membrane with antimicrobial effect
Gablech, Evelína ; Farka,, Zdeněk (referee) ; Soukupová,, Jan (referee) ; Drbohlavová, Jana (advisor)
Tato práce se zabývá zlepšením antimikrobiálních vlastností komerčních polymerních membrán používaných v mlékárenském průmyslu pro filtraci mléčných výrobků jako je syrovátka. Tyto membrány trpí kontaminací způsobenou mikroorganismy přítomnými v mléce během procesu filtrace. Toto biologické znečištění ovlivňuje životnost membrány i samotný filtrační proces. Pro ochranu membrány před vytvořením biofilmu z mikroorganismů byly tyto membrány modifikovány pomocí plazmových metod tak, aby došlo k funkcionalizaci aminovými skupinami pro následnou imobilizaci nanočástic stříbra a selenu. Antimikrobiální aktivita obou typů nanočástic a membrán s imobilizovanými nanočásticemi byla stanovena proti buněčným kmenům Staphylococcus aureus a Escherichia coli.
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Preparation of edible antimicrobial packaging
Kozubová, Petra ; Dzurická, Lucia (referee) ; Skoumalová, Petra (advisor)
This bachelor’s thesis is focused on preparation and characterization of eatable packaging. Eatable packaging consists of two components, antimicrobial component and base of packaging. The task of eatable packaging is to protect product against antimicrobial attack and to extend durability of the product. As antimicrobial components were used water and oil extracts of several herbs (mint, nettle, lavender, cinnamon, cloves, vanilla, ginger and rhinoceros). Oil extracts were also encapsulated into liposomes for better application. Firstly, concentrations of polyphenoles and antioxidants of extracts were determined. Oil extract of clove contained the highest concentration of both determined substances. Encapsulation efficiency, stability and size of liposomes were tested too. All prepared liposomes were stable and relatively of the same size. Also high encapsulation efficiency was observed. Next, antimicrobial activity of prepared extracts and liposome particles against yeast Candida glabrata and two bacteria strains Escherichia coli and Staphycococcus epidermidis was tested and the high antimicrobial activity reported mainly all tested liposomes. Then alginate, chitosan and carboxymethylcellulose and their combinations respectively were used as bases of packaging. Created film had to meet several parameters, especially suitable sensory properties such as pleasant taste and smell, as well as invisibility, gloss, affordability and suitable manipulability. Combination of 2% carboxymethylcellulose and 1% alginate in a ration of 2:1 with liposomes of mint as antimicrobial component achieved the best results.
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Characterization of plasma activated water for biomedical applications
Šindelková, Kateřina ; Dzik, Petr (referee) ; Kozáková, Zdenka (advisor)
The aim of this master thesis is to characterize plasma activated water (PAW) prepared in various plasma systems using direct and indirect interaction of plasma with liquid or its surface. Plasma was generated by electric discharges at atmospheric pressure. The prepared plasma-activated water was studied with respect to its use in biomedical applications. The theoretical part deals with plasma activated water. It contains a description of the PAW preparation, its characterization in terms of produced particles or its physico-chemical properties. Also, methods for antimicrobial activity estimation or colorimetric determination of produced particles are described in this section. In the experimental part of this work, the types of discharges that were used for the PAW preparation and their comparison are presented. Two types of liquids were selected for the activation, namely distilled and tap water. Subsequently, concentrations of selected reactive particles in PAW (hydrogen peroxide, nitrates and nitrites) produced in three different plasma systems were determined. Besides the comparison of reactive particles production in various systems, their time stability was studied as well. Over time after the PAW preparation, the values of active particles concentrations have changed due to mutual interactions between the particles. Mainly, nitrites were oxidized to nitrates or vice versa depending on the PAW type and other conditions. Part of the work was also monitoring selected physical properties of PAW, namely pH value and specific conductivity. It has been found that PAW does not retain its activated properties for too long, depending on the type of preparation and methods of storage. Therefore, one of the important goals of this work was to determine and compare suitable storage conditions for PAW with respect to its potential biomedical applications.
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Determination of antimicrobial activity of herbal extracts
Žitková, Barbora ; Veselá, Mária (referee) ; Vítová, Eva (advisor)
The aim of this bachelor thesis was to observe the antimicrobial activity of selected herbal extracts and essential oils against three selected microorganisms, bacteria – Bacillus cereus, Escherichia coli and the yeast Candida glabrata. Two diffusion methods were used to verify and compare the antimicrobial activity, namely the diffusion well and disk method. The theoretical part describes the characteristic of plants from which extracts and oils were made. It also focuses on active substances, vitamins and minerals contained in herbs. Other methods that can be used to determine antimicrobial activity are also mentioned in the work. At the end of the theoretical part the characteristic of the microorganisms used for observation is mentioned. The result of the diffusion well method shows that only eucalypt oil showed antimicrobial activity against all selected microorganisms. It was most effective against Bacillus cereus with an inhibition zone size of 1.73 ± 0.11 cm. The result of the diffusion disk method shows that there are two oils which showed antimicrobial activity against selected microorganisms, namely marrow and eucalypt oil. Nevertheless, the most effective oil was made of mint against Bacillus cereus with an inhibition zone size of 1.57 ± 0.31 cm.
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Preparation and testing of application forms for natural antimicrobial substances
Vajglová, Klára ; Bokrová, Jitka (referee) ; Márová, Ivana (advisor)
The goal of this bachelor thesis was the study of antimicrobial and antioxidant effects of some herbal extracts: cloves, nettle, sage, chamomile, rosemary, elderberry, lavender and also lysozyme. Further, herbal extracts effect on Gram positive and Gram negative bacteria were compared. In the theoretical part were briefly characterized lysozyme, polyphenols, flavonoids and selected strains of microorganisms. In the experimental section characterization of herbs with antimicrobial and antioxidant effect was proved. Particles containing herbal extracts were prepared and encapsulation efficiency was determined. In some of tested herbs encapsulation efficiency of up to 80% was reached. Stability of the prepared liposomes was tested in the model digestive conditions and after 1 week and 1 month incubation period in model foods. Antimicrobial activity was tested on selected representatives of Gram negative and Gram positive bacteria. Gram positive bacteria were more sensitive to herbal extracts and liposomes containing encapsulated herbs, while lysozyme exhibited higher effect to Gram negative bacteria. Prepared particles with encapsulated antimicrobial extracts are especially suitable for use in the food industry.
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Silver based raw materials for cosmetic purposes
Čaková, Adriana ; Ďubašáková, Mária (referee) ; Zemanová, Jana (advisor)
The purpose of this bachelor’s thesis was a research about silver based cosmetic products and determination of antimicrobial activity on certain species of microorganisms by chosen silver based cosmetic products. Theoretical part is focused on the problematics of silver based cosmetic products, on their main purpose, physically chemical characteristics and toxicological profile. In the theoretical part is also mentioned problematics of legislative, mainly the safety and real effectivity of tested cosmetic products. Experimental part was focused on determination of antimicrobial activity of chosen silver based cosmetic products. Two silver based cosmetic product were used to determined antimicrobial activity on selected microorganisms Bacillus subtilis, Bacillus cereus, Micrococcus luteus, Kocuria rosea, Serratia marcescens a Candida vini. From result it is apparent, that both of used Cosmetic product showed antimicrobial activity, but not on every used microorganism.
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Preparation and application of combined functionalized nanomaterials with antimicrobial effect in food and cosmetics
Vojteková, Vanesa ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
The presented diploma thesis is focused on the preparation of combined nanomaterials that were functionalized with an antimicrobial ingredient. Liposomes were prepared without the addition of polyhydroxybutyrate but also with its addition. The nanofibers were obtained from gelatin solution by electrospinning. Thymol, eugenol, curcumin and vitamin E were used for functionalization. In the theoretical part, individual bioactive components, materials for the preparation of nanoparticles and nanofibers as well as methods of synthesis of these materials were characterized. The applications of the prepared nanoparticles as preservatives in the food industry and applications of nanofibers in wound healing and in the cosmetics industry have also been described. In the experimental part, the antioxidant activity of the active substances was determined. Two types of liposomes were prepared and evaluated for size, stability and encapsulation efficiency. Subsequently, the release rate of active substances from the prepared liposomes was monitored. Nanofibers with combinations of substances that were encapsulated in liposomes were prepared by electrospinning. The antimicrobial activity of the active ingredients, nanofibers and nanomaterials was monitored on three strains of microorganisms, namely Micrococcus luteus, Staphylococcus epidermidis and Escherichia coli. The individual substances in pure as well as encapsulated form were combined with each other to observe the possible synergistic effect. The prepared nanoparticles and nanofibers with antimicrobial components were tested for cytotoxicity on human keratinocytes. The nanofibers were also subjected to a scratch test, which simulates the wound healing process.
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Determination of antimicrobial and antioxidant activity of selected herbal extracts
Čaková, Adriana ; Němcová, Andrea (referee) ; Vítová, Eva (advisor)
Tetradenia spp. is herb naturally growing in Africa and is part of family called Lamiaceae. The herb is used in traditional medicine to cure malaria, angina or as treatment for tropical skin diseases. Maceration was chosen from number of extraction methods, to obtain bioactive compounds from this plant. Optimization was performed with aim to retrieve as much of bioactive compounds as possible. Optimal conditions chosen were: temperature 60 °C, extraction time 40 minutes, solvent 40% ethanol and solid-solvent ratio 1:5. In total 63 aromatic active compounds were found in optimal extract. Terpenes were the most abundant (88,60 %), from them oxygenated monoterpenes (55,65 %) and monoterpenes (29,52 %). Compounds with highest percentage quantity were camphor (51,76 %), cis--ocimene (8,17 %), 3-octyl acetate (7,71 %), trans--ocimene (6,76 %), -terpinene (4,93 %), o-cymene (3,81 %), terpinolene (1,33 %), limonene (1,33 %), camphene (1,19 %) and borneol (1,20 %). Further, total phenolic content was 0,31 ± 0,02 mgGAEml-1, which equals 1,52 ± 0,11 mgGAEg-1 of plant. Antioxidant activity was 417,56 ± 32,84 gTEACml-1 and percentage of radical scavenging activity ABTS•+ was 88,99 ± 7,00 %. Finally antimicrobial activity was determined against bacteria Bacillus cereus, Escherichia coli and yeast Candida glabrata. Against E. coli and C. glabrata there was no inhibition exhibited. Against B. cereus there was seen mild inhibition activity. The results confirm that Tetradenia spp. contain a number of interesting aroma active compounds, which shows antioxidant and antimicrobial activity. The herb has a good potential as natural source of nutritious and sensory active compounds to be used into various foods.
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Rosehip – the source of natural compounds
Motúzová, Eliška ; Vítová, Eva (referee) ; Veselá, Mária (advisor)
The goal of this bachelor thesis was to study the antimicrobial activity of various extracts of rosehip tea. As well as to determinate concentration of biologically active compounds, polyfenols and flavonoids, and antioxidant activity in these teas. Teoretical part describes basic information about Rosa canina, general classification of tea, summary of biologically active compounds and basic methods of extraction. Practical part is focused on determination of anioxidant acivity, comcentration of polyfenols and flavonoids in tea extracts and detection of animicrobial activity of these extracts against bacterial strains Serratia marcescens and Micrococcus luteus. The results of this theasis show that aqueous extracts of rosehips tea are animicrobialy active. It was also found, that these extracts have hight contents of polyphenols and flavonoids.
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Antimicrobial activity of rosehip teas
Ďubašáková, Mária ; Vespalcová, Milena (referee) ; Veselá, Mária (advisor)
The aim of this bachelor theses was to determine the concentration of biologically active substances such as polyphenols and flavonoids and also total antioxidant activity of tea extract of rosehip and also research antimicrobial activity and the effective concentration of the extracts against selected bacteria. Theoretical part is focuses on the description of natural antioxidants and active effect against free radicals, description and distribution of tea, botanical and chemical description od rosehip and basic information about bacteria. There is section describe selected methods for the determination of polyphenols, flavonoids, total antioxidant activity of these extracts, and verification of antimicrobial activity against grampositive and gramnegative bacteria in experimental section. From the results is flow, that the analyzed extracts have no inhibition activity against bacteria. Also was found that aqueous extracts has high proportion flavonoids and polyphenols.
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