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Study of sterilization effect of diaphragm discharge in liquids
Holíková, Lenka ; Slámová, Jitka (referee) ; Kozáková, Zdenka (advisor)
The main objective of this thesis is to study the sterilizing effect of diaphragm discharge in liquids. Sterilization is a process, which can eliminate all forms of life. Generally, sterilization is divided into physical and chemical methods. Plasma sterilization is ranked among physical methods although the action of chemical processes participates in the decontamination as well. Effects of UV radiation, free radicals and temperature are utilized in these methods. Fungi spores of Aspergillus niger F8189 and bacteria spores of Bacillus subtilis are selected as model organisms. Aspergillus niger microorganism is suitable for its resistance to changes in pH and it is viable in a wide range of pH values. Bacillus subtilis is chosen because of a good heat resistance. Diaphragm discharge is one of the possible types of electrical discharges in generated liquids. It is a low-temperature plasma, which is generated using a high DC voltage. In the created plasma streamers various physical and chemical processes rise. The chemical processes are mainly the generation of active species and particles that initiate subsequent chemical reactions and attack mould spores and bacteria in liquids. The physical processes include shock waves, strong electric field and ultraviolet radiation. Experiments were conducted in a reactor with separate cathode and anode space. In the dielectric barrier PET diaphragm with a pin-hole (initial diameter of 0.4 mm) was attached. Enlargement of the hole was observed as a result of degradation of material at the edge of holes due to the discharge. Degradation of spores was observed, depending on the time and on the input power. Other parameters measured were pH, conductivity and temperature. Experiments did not show any difference of discharge activity in the cathode and anode area. The main factor in the removal of spores Aspergillus niger was probably the temperature because no demonstrable effect of sterilization by the diaphragm discharge operation had been observed when heat resistant Bacillus subtilis was used. Also, it was made an attempt, which has been studied only the temperature effect of the fungi spores of Aspergillus niger. The samples were placed in a thermoregulator, where it was simulated the same temperature increase as at the discharge. The experiment had a similar course as an attempt at the discharge.
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Processing and analysis of the human lung microbiome from nanopore sequencing data
Molíková, Anna ; Bartoň, Vojtěch (referee) ; Nykrýnová, Markéta (advisor)
This bachelor’s thesis deals with processing and analysis of the human lung microbiome from nanopore sequencing data. Firstly this thesis introduces the lung microbiome and its composition in health and illness. Then it focuses on generations of sequencing technologies, mainly describing nanopore sequencing. The last chapter discusses different methods used for lung microbiome analysis. The practical part of this thesis preprocesses sequencing data, followed by their taxonomic analysis and the search for antibiotic resistance genes. From the obtained results, the composition of the lung microbiome in each of the processed samples is then evaluated.
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Mikroorganismy kontaminující nápoje z čerstvého ovoce a zeleniny (smoothie)
Keresztesová, Nela
The diploma thesis is focused on microorganisms contaminating drinks from fresh fruits and vegetables intended for direct consumption. The theoretical part focuses on technologies for the production of fruit and vegetable juices and the most common methods of preservation. Another part of the work is focused on microbial contamination (bacteria, fungi, yeasts and mycotoxins). In the experimental part, this work deals with microbiological analysis, which determined the presence of contaminating microorganisms. The microbiological quality was compared for fresh unprocessed juices intended for direct consumption with juices treated with high pressure or gentle pasteurization. It was confirmed that higher numbers of microorganisms were found in fresh juices, but also that an increase in microorganisms was noticeable after the minimum shelf life had expired.
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Technologicky významné mikroorganismy v nápojovém průmyslu
Prokopová, Linda
This bachelor thesis was elaborated in 2019 and 2020 at the Department of Post-Harvest Technology of Horticultural Products of the Faculty of Horticulture, Mendel University in Brno. Bachelor thesis deals with the division of microorganisms, description of their nutrition and reproduction, important genera in terms of both positive and negative. The influence of microorganisms for food industry and important fermentation processes for beverage industry is described. All important microorganisms for the production of wine, beer, spirits and milk fermented beverages are included. The work also follows the microorganisms, which cause various defects in the bev-erage.
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Mikrobiologické parametry vody ze soukromých studní
Hanáková, Dorota
The bachelor thesis is focused on microbiological parameters of drinking water from private wells. The theoretical chapter is focused on the properties and legislative requirements of drinking water, especially from the microbiological point of view. Microbiological analysis of 7 water samples from private wells was performed in the experimental part of the thesis. The analyzes were carried out in October, November and January. The resulting values were compared with legislative requirements and other studies carried out so far. Six of seven samples, therefore 85.7%, did not comply with the parameters stipulated by legislation. Consuming this water might constitute a health risk. The results of the given samples were compared in individual months. Most of the samples showed a trend of decreasing number of microorganisms with decreasing outside temperature.
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Microbial analysis and identification of organisms in products from young cocco
Palyzová, Andrea ; Marešová, Helena
The collaboration focused on the isolation and identification of bacterial strains in young coconut products, the comparison of their microbial profiles and the monitoring of stability over time. Yoguard and Keefir products contain highly functional probiotic bacteria and probiotic yeasts. The main microorganisms contained in yoghurts and keefires include Lactobacillus, Streptococcus, Enterococcus, Lactococcus, Leuconococcus, Saccharomyces.\nThe main microorganisms contained in yoghurts and keefires include Lactobacillus, Streptococcus, Enterococcus, Lactococcus, Leuconococcus, Saccharomyces.\n\n\n\n\n\n\n\n\n\n\n
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Diversity and function of pattern structures in the microworld
Hirnerová, Anna ; Škaloud, Pavel (advisor) ; Němcová, Yvonne (referee)
This thesis summarizes current knowledge of patterns and structures at various scales, with an emphasis on the use of these patterns in the microworld and also on the materials that are most often used. Patterns are applied in all areas of natural processes and human activity. There are many analogous models at different scales, but we do not know if they have the same self-organizing mechanisms. Many patterns formed by microorganisms can be prepared without their presence, on the basis of physical and chemical methods, so they are probably created under certain parameters that can be influenced by a given protist. These patterns are evolutionarily advantageous for microorganisms, because they provide them with a number of functional adaptations, mainly in connection with defense against predators and movement in the water column, which is based on the organism's life strategy. The mathematical description of the pattern is extremely important for its further research and for determining the laws that have allowed the organism to benefit from its parameters. Keywords: pattern, structure, convection, reaction - diffusion model, geometry, protist, microorganism, skeletons, shells, scales
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Comparison of antimicrobial effect of emulsions for cleaning and dissinfection
Chrápavá, Edita ; Dzurická, Lucia (referee) ; Márová, Ivana (advisor)
Currently, hand disinfectants and other disinfectants are in high demand. Due to the pandemic and the spread of Covid-19, they are used by society daily. The reason for their use is not only to prevent the spread of bacteria and other microorganisms from the hands to another part of the body or objects, but also to prevent the spread of the disease. The subject of the bachelor thesis is the control of antimicrobial effects of several commonly available disinfectants using broth and agar dilution methods. From the measured data, the absorbance was processed and subsequently viability of the culture.
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Biochemical markers of soil microbial community and functioning and antropogenic stress
Kukla, Jaroslav ; Frouz, Jan (advisor) ; Hruška, Jakub (referee) ; Novotný, Čeněk (referee)
The soil microbial community has a major impact on ecosystem processes on a global scale. Anthropogenic stress has a significant effect on the composition, biomass and activity of the microbial community. In addition, this effect depends not only on the anthropogenic activity, but also on the environmental conditions. Modern analytical and molecular methods, including the use of biochemical markers, can be well used to monitor changes in the microbial community. These methods do not monitor the community directly, but detect the substances that are secreted and transformed by microbes and, last but not least, those that are part of them. The amount of these biochemical markers reflects the biomass, condition and taxonomic composition of a particular microbial community. In the presented work, these markers were used to monitor the response of microorganisms in various ecosystems which are affected directly or indirectly by human activity. The results of the dissertation are presented in four articles. Three of them have been published in international journals with IF and one is prepared in the form of a manuscript for publication. The first publication presents the results of research exploring the impact of traditional agriculture in Papua New Guinea on the soil microbial communities, soil...
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Characterization of microorganisms with biodegradation potential for sulfonamides
Sedláček, Jan ; Palyzová, Andrea (advisor) ; Mikušová, Gabriela (referee)
Sulfonamides are antibiotics that are frequently used both in human and veterinary medicine. The combinations of abundant use of these antibiotics and their natural resistance to decay leads often to long term persistence in the environment. This accumulation, especially in living organisms, may lead to subsequent toxicosis. Also, presence of these antibiotic in nature poses problems with regard to the spread of genes for antibiotic resistance between potential pathogens. These facts led to an increase interest in studying the sulfonamide biodegradation and subsequent sulfonamide removal from the environment. In this work it was possible to isolate and characterize the microorganism Acinetobacter sp. strain 49. This microorganism was able to biodegrade under right conditions sulfamethoxazole with 80 % efficiency. Sulfamethoxazole is one of the most commonly found sulfonamide in the nature.
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