|
|
Study of plasma interaction with yeast Candida glabrata
Trebulová, Kristína ; Lehocký, Marián (referee) ; Krčma, František (advisor)
The main subject of this diploma thesis is the study of low temperature discharges´ effects on the yeast Candida glabrata (C. glabrata). Cold atmospheric-pressure plasma (CAPP) technology has achieved a great deal of attention in recent years, due to its positive attributes, including high efficiency against a wide range of microorganisms, ease of operation, economic simplicity and also environmental friendliness. The research of CAPP focuses mainly on the applications involving the treatment of cancer and superficial infections as well as sterilization technologies in medicine, food and agriculture. Various effects and also some mechanisms of inactivation of bacteria and tumor cells have been explained over the last decade but the effects and mechanisms of fungi inactivation have not yet been sufficiently investigated. The aim of this work is to verify the effects of chosen low-temperature discharges on the model yeast example C. glabrata, in order to establish basic plasma set-up for further studies and experiments in vivo and to expand a global knowledge about the antifungal effects of CAPP. In this study, 5 different discharges, namely: microwave (unipolar and surface wave) in the form of plasma torch, transient spark, corona discharge in the form of corona pen and dielectric barriere discharge (DBD) in the form of DBD pen were tested. All discharges were tested by direct application onto a 24-hour inoculum of C. glabrata inoculated on agar plates. The results were evaluated based on the size and stability of the inhibition zones formed in the post treatment cultivation. From the individual measurements optimal conditions for testing the inhibitory effects of low temperature discharges on the selected yeast were determined. The microwave discharges (unipolar and surface wave) were chosen to be the most effective in the inhibition of C. glabrata. The measurements were therefore pursued with these discharges under selected conditions corresponding to chosen application of sterilization of surface infections in living organisms. The unipolar microwave discharge was chosen to be the most effective discharge for the potential treatment of superficial candidiasis. The indirect effect of plasma was also investigated using plasma activated liquid (PAL) on inoculated yeast culture. PAL was prepared using 3 different discharges: Dielectric Barrier Discharge (DBD), Unipolar Microwave Discharge and Electric Discharge in Liquid. The results of this work prove significant inhibitory effects of CAPP on the yeast C. glabrata, within the limits of in vitro cultivation and the so-called flat biology. The overall inhibitory effects are directly proportional to the irradiation time, the magnitude of applied power and also the area covered by the discharge. In terms of the initial cell concentration an indirect dependency can be observed, but it can also be stated that this factor is less significant compared to the other examined factors. Observations of the effects of plasma activated liquid (PAL) indicate that a single application of PAL under selected conditions is not alone enough for successful inhibition of C. glabrata.
|
|
|
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.
|
|
|
Study of plasma jet effects on yeast
Trebulová, Kristína ; Skoumalová, Petra (referee) ; Krčma, František (advisor)
The purpose of this work is to study the effects of a 2.45 GHz microwave plasma jet on the yeast Candida glabrata. The microwave plasma was generated by a surfatron resonator and as a working gas pure argon at constant flow rate 5 Slm was used. Thanks to a high number of active particles generated in a low temperature plasma, this type of plasma has become highly popular, especially thanks to its bactericidal effects. However, its antifungal effects and mechanisms of fungal inactivation have still not been fully understood. Therefore, the study focuses on the antimycotic effects of the low temperature plasma in a form of a microwave discharge on Candida glabrata as a model yeast example. The principal focus is on the measurement and evaluation of changes in inactivation effects caused by varying the initial concentration of Candida glabrata cells, applied power, and the exposure time. The theoretical part presents the basic information concerning Candida glabrata, its pathogenicity, virulence and infectivity. Furthermore, plasma in general, various types of discharges and their applications in the food and biomedical industries are discussed. The experimental part focalizes on the determination of the inactivating effects of the microwave plasma jet on the yeast Candida glabrata. The experiment consists of applying the discharge on a freshly inoculated colony of Candida glabrata on agar plates and observing inhibitory effects in the form of inhibitory zones formed after subsequent cultivation. The inhibition of yeasts by the microwave discharge is interesting scientifically due to its promising results, which have also been proven in this work, but also economically, especially due to the use of argon. Argon as a carrier gas is much cheaper than helium and colder than common atmospheric pressure discharges in air such as DBDs, corona or glow discharges.
|
|
|
Study of low temperuture microwave plasma on yeats
Petrová, Veronika ; Kozáková, Zdenka (referee) ; Krčma, František (advisor)
This bachelor thesis subject is the study of low temperature microwave plasma torch on yeasts. For this purpose, the yeast Candida Glabrata was selected. Three parameters, which have different effects on the size of the inhibition zones and their time stability, are monitored. The effect of sample concentration, exposure time, and applied power (9 W and 12 W) are investigated. A microwave torch discharge at atmospheric pressure is used. The working gas is argon and a constant flow rate of 5.0 Slm was maintained throughout the experiment. The visible end of the discharge is in direct contact with the sample surface during the experiment. In the experimental part, although the microwave torch discharge used was found to be unstable, its sterilizing effect on yeast was demonstrated.
|
|
|
TiO2 nanoporous surfaces and their properties
Roček, Vojtěch ; Urbánková, Kateřina (referee) ; Drbohlavová, Jana (advisor)
This thesis is focused on creation nanostructured surfaces of titanium dioxide and the use of photocatalytic activity of these surfaces for antimicrobial applications. The work is divided into nine main chapters, in which the literature search for producing these surfaces, the principle of photocatalysis and their typical specifics was made. These theoretical findings are then used to form such layers, analyzing their chemical and physical properties and practical verification of their antimicrobial activity. This work experimentally verified processes to ensure the increase of antimicrobial activity. The results and findings are discussed in the conclusion.
|
|
|
Biological effects of various hemp fractions
Vacková, Hana ; Skoumalová, Petra (referee) ; Němcová, Andrea (advisor)
Cannabis is the only plant which contains cannabinoids and thanks to these compounds it has enormous potential. This thesis deals with the analysis of technical hemp. Effects of cannabinoids and methods used for cannabis analysis are discussed in the theoretical part. The experimental part includes spectrophotometric characterization of cannabis, it´s antimicrobial effects and thin layer chromatography analysis. Three sorts of Cannabis sativa L. were analyzed, namely Finola, Fedora and Kompolti. Firstly, the content of polyphenols, flavonoids and antioxidant activity in prepared tinctures were determined. Moreover, antimicrobial test were performed using disk test and turbidity determination. Gram-positive and Gram-negative bacteria and yeast organism were tested. It was found that cannabis tinctures possess good antimicrobial effects. Some of them are comparable with synthetic antibiotics. Finally, thin layer chromatography enabled visualization of cannabinoids in prepared tinctures.
|
|
|
Study of low temperature plasma direct application on yeasts Candida Glabrata and bacteries
Petrová, Veronika ; Kodedová,, Marie (referee) ; Krčma, František (advisor)
The subject of this thesis is to study the interactions of the low-temperature microwave plasma with selected microorganisms Candida glabrata, Staphylococcus epidermidis, and Escherichia coli and their combinations. The inhibitory effect of the plasma on these microorganisms is monitored on selected solid nutrient media and in suspension (nutrient medium and PBS). The inhibitory effect on the mixed cultures of these microorganisms is also studied on the solid nutrient media. The surface wave microwave discharge is used, with argon as a working gas. For the experiment on the solid nutrient media, a constant gas flow rate of 5,0 Slm and a power fluctuating between 8-10 W are maintained throughout the experiment. For the suspension experiment, a constant gas flow rate of 2,0 Slm and 13 W power are maintained throughout the experiment. The inhibitory effects of plasma on the solid nutrient media were observed on the individual microorganisms as well as on the mixed cultures. It was found that the microorganisms treated by plasma on the solid nutrient media were inhibited and uncultivable, while their cytoplasmic membrane remained intact. When the microorganisms were treated in suspension, individual cells were killed, but the efficiency was low. This was caused by the experimental setup, specifically due to the plasma only being formed in argon (no intermixing with air), as the capillary was submerged in the treated suspension.
|
|
|
Study of plasma interaction with yeast Candida glabrata
Trebulová, Kristína ; Lehocký, Marián (referee) ; Krčma, František (advisor)
The main subject of this diploma thesis is the study of low temperature discharges´ effects on the yeast Candida glabrata (C. glabrata). Cold atmospheric-pressure plasma (CAPP) technology has achieved a great deal of attention in recent years, due to its positive attributes, including high efficiency against a wide range of microorganisms, ease of operation, economic simplicity and also environmental friendliness. The research of CAPP focuses mainly on the applications involving the treatment of cancer and superficial infections as well as sterilization technologies in medicine, food and agriculture. Various effects and also some mechanisms of inactivation of bacteria and tumor cells have been explained over the last decade but the effects and mechanisms of fungi inactivation have not yet been sufficiently investigated. The aim of this work is to verify the effects of chosen low-temperature discharges on the model yeast example C. glabrata, in order to establish basic plasma set-up for further studies and experiments in vivo and to expand a global knowledge about the antifungal effects of CAPP. In this study, 5 different discharges, namely: microwave (unipolar and surface wave) in the form of plasma torch, transient spark, corona discharge in the form of corona pen and dielectric barriere discharge (DBD) in the form of DBD pen were tested. All discharges were tested by direct application onto a 24-hour inoculum of C. glabrata inoculated on agar plates. The results were evaluated based on the size and stability of the inhibition zones formed in the post treatment cultivation. From the individual measurements optimal conditions for testing the inhibitory effects of low temperature discharges on the selected yeast were determined. The microwave discharges (unipolar and surface wave) were chosen to be the most effective in the inhibition of C. glabrata. The measurements were therefore pursued with these discharges under selected conditions corresponding to chosen application of sterilization of surface infections in living organisms. The unipolar microwave discharge was chosen to be the most effective discharge for the potential treatment of superficial candidiasis. The indirect effect of plasma was also investigated using plasma activated liquid (PAL) on inoculated yeast culture. PAL was prepared using 3 different discharges: Dielectric Barrier Discharge (DBD), Unipolar Microwave Discharge and Electric Discharge in Liquid. The results of this work prove significant inhibitory effects of CAPP on the yeast C. glabrata, within the limits of in vitro cultivation and the so-called flat biology. The overall inhibitory effects are directly proportional to the irradiation time, the magnitude of applied power and also the area covered by the discharge. In terms of the initial cell concentration an indirect dependency can be observed, but it can also be stated that this factor is less significant compared to the other examined factors. Observations of the effects of plasma activated liquid (PAL) indicate that a single application of PAL under selected conditions is not alone enough for successful inhibition of C. glabrata.
|
|
|
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.
|
|
|
Study of low temperuture microwave plasma on yeats
Petrová, Veronika ; Kozáková, Zdenka (referee) ; Krčma, František (advisor)
This bachelor thesis subject is the study of low temperature microwave plasma torch on yeasts. For this purpose, the yeast Candida Glabrata was selected. Three parameters, which have different effects on the size of the inhibition zones and their time stability, are monitored. The effect of sample concentration, exposure time, and applied power (9 W and 12 W) are investigated. A microwave torch discharge at atmospheric pressure is used. The working gas is argon and a constant flow rate of 5.0 Slm was maintained throughout the experiment. The visible end of the discharge is in direct contact with the sample surface during the experiment. In the experimental part, although the microwave torch discharge used was found to be unstable, its sterilizing effect on yeast was demonstrated.
|
guest ::
