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Influence of stress and nutritional conditions on carotenogenic yeast and microalgal metabolism
Sikorová, Pavlína ; Byrtusová, Dana (referee) ; Szotkowski, Martin (advisor)
This bachelor thesis describes the infuence of biological stress (co-cultivations) on the growth and metabolism of selected carotenogenic yeasts and microalgae. The metabolites of these microorganisms are chlorophyll and carotenoids, which are natural pigments and antioxidants. In theory, co-cultivation is a cultivation where microorganisms mutually support each other in the growth and production of metabolites. This would cause the increased production of previously mentioned chlorophyll and carotenoids. The theoretical part of the work is focused on the description of selected species of yeasts and microalgae and further discusses in more detail, the topics of stress factors depending on the growth and metabolism of microorganisms. The experimental part then deals with different types of cultivation and cocultivation and tries to optimize the production media and find the best symbiotic yeasts and microalgae. Furthemore the issue of different ratios of microorganisms in co-cultivations is also addressed here. The cultivated yeasts strains were Rhodotorula kratochvilovae, Rhodosporidium toruloides and Phaffia rhodozyma. And microalgae strains were Desmodesmus acutus, Desmodesmus quadricauda, Coccomyxa sp., Chlorella sorokiniana, Chlamydomonas reinhardtii and Scenedesmus obliquus. Cultivated cyanobacterium was Synechoccocus nidulans. The most successful co-cultivation experiment was the one with R. kratochvilovae and yeast Desm. quadricauda. This experiment was very succesful in all aspects.
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Biological role of PHA cycle in bacterium Rhodospirillum rubrum
Šarköziová, Patrícia ; Obruča, Stanislav (referee) ; Slaninová, Eva (advisor)
The diploma thesis deals with the study of polyhydroxyalkanoates (PHAs) production and their protective effects during exposure of the bacterial strain Rhodospirillum rubrum to various stress factors. The theoretical part of this work is focused on the characterization of PHAs and used bacterial strain. In the first part of the experimental work carbon substrates for biomass growth and PHA production in different time intervals (24, 48, 72 and 96 hours) were investigated. Acetate, fructose, hexanoate and malate served as a carbon source. The second part of this work was focused on the selection of a suitable fluorescent probe for the bacterium Rhodospirillum rubrum (propidium iodide, SYTOXTM, fluorescein diacetate), which was used to determine the viability of bacterial cells using flow cytometry. This method was used to determine the viability of bacterial cells after their exposure to various stress factors (thermal stress, freezing and thawing, ethanol stress, osmotic stress, peroxide stress, pH stress and UV stress). Finally, the growth curve of bacteria Rhodospirillum rubrum was determined by measurement of the optical density.
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Characterization of biological effects of extracts obtained from yeasts and autotrophic microorganisms
Špačková, Dominika ; Bendová, Agáta (referee) ; Szotkowski, Martin (advisor)
Carotenogenic yeasts and microscopic autotrophic microorganisms are increasingly being studied in the biotechnology industry because of their ability to produce a variety of substances with a wide range of utilization. These substances mainly include lipids and carotenoids, which are used in the food and pharmaceutical industries. The aim of this bachelor thesis is to determine the way these microorganisms behave in the presence of stress factors, and which of them would have a positive effect on the production of metabolites that can be further used in various industries. The theoretical part is dedicated to a characterization of substances produced by carotenogenic yeasts, cyanobacteria and microalgae, which will be further analyzed in the experimental part. The metabolites mainly include carotenoids, which are a wide group of naturally occurring pigments that possess, among other things, antioxidant and provitamin activity. No less important substances produced by these organisms are lipids, which are part of cell membranes, they also serve as a reservoir of energy, and the substances contained in lipids are part of the precursors of many hormones. Yeast cell walls also contain -glucans, which have many beneficial effects on immunity and human health. Due to this fact, interest in their research have been rising recently. The analytical methods used to determine these substances are also mentioned, as well as stress factors and their effects on the cells of the mentioned organisms. The experimental part deals with the exposure of these microorganisms to oxidative stress and stress caused by heavy metals. The aim was to analyze which concentrations of these stress factors are lethal to microorganisms, and which of them are optimal for increase of the production of the above-mentioned substances. Of the yeast strains, the strains Sporidiobolus pararoseus and Rhodotorula mucilaginosa achieved increased production of metabolites due to selenate ions. In contrast, cobalt had a beneficial effect only on the accumulation of lipids and -glucans in cells. The positive effect of selenium was also observed in the strain Chlorella minutissima and Arthrospira maxima, however, the most remarkable changes in the production of metabolites were achieved by the addition of the optimal concentration of the solution inducing oxidative stress.
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Cultivation of carotenogenic yeasts in the presence of biological stress induced by selected strains of autotrophic microalgae
Sikorová, Pavlína ; Byrtusová, Dana (referee) ; Szotkowski, Martin (advisor)
Presented Master’s thesis was focused on biological and nutrient stress in cultivations of green microalgae and carotenogenic yeasts. The focus of interest was production of biomass in different types of cultivation media, production of metabolites (mainly carotenoids and chlorophylls) and also production of lipids and lipophilic substances. All types of aplied stress was used to lead to an increased production of biomass and metabolites. The theoretical part deals with introduction of individual genera of carotenogenic yeast and green microalgae. The types of cultivation stress were also described. In addition, the analytic methods for qualitative and quantitative analysis are also introduced. The experimental part was focused on the study of biomass, carotenoids, chlorophylls, coenzym Q, sterols and lipids production. Biological stress was induced by cocultivation of microalgae and yeasts together.Nutrient stress meant adding macroelements or waste oils to the medium. Yeasts of interest were Rhodosporidium toruloides, Rhodotorula kratochvilovae and Sporobolomyces pararoseus. Microalgae was represented by Desmodesmus acutus, Desmodesmus armatus, Scenedesmus obliquus, Desmodesmus velitaris, Desmodesmus communis, Coccomyxa sp. Chlamydomonas reinhardtii and Chlorella minutissima. Generally the most successful multicultivator experiment was cocultivation with yeast R. kratochvilovae. In the case of cultivation on waste oils, the best producers of biomass and metabolites were co-cultivation experiments with the yeast R. toruloides. In microalgal experiments, it was found that nutritional stress in the form of glycerol added to the medium had an inhibitory effect on the growth and metabolism of microalgae.
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Nursing students'stress factors in clinical practice
Kurišová, Miroslava ; Mádlová, Ivana (advisor) ; Javůrková, Alena (referee)
The thesis focused on the psychological burden of students on professional practice and the related self-confidence of students. I set myself the following goals: 1. To analyze the current state of the issue of mental stress of students in professional practice using scientific sources and articles in Czech and foreign literature 2. Prepare a non-standardized structured questionnaire and assign the target respondents - students of Charles University 2nd and 3rd Faculty of Medicine / Faculty of Medicine / in Prague and students of the Faculty of Health Care of the Catholic University in Slovakia 3. Identify potential differences in the identification of stressors in the course of professional practice and assessment of load by students 4. Propose recommendations for improving education and training during studies The methodology: the work consists of data analysis obtained using a structured questionnaire, which was distributed electronically among students of General Nursing in 2nd and 3rd year in Czech Republic and in the 2nd and 3rd year in Slovakia. The final number of respondents for both universities was 66, a rate of return of 72%. MS excel 2016 spreadsheet processor and IBM SPSS Statistics software version 22 (USA) and Statistica version 12 were used for data analysis. The hypotheses were...
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Vliv stresu na pracovní výkon zaměstnanců
Pernicová, Natálie
Pernicová, N. The influence of stress on the work performance of employees: Men-del University in Brno, 2023. The bachelor thesis deals with the influence of stress on the work performan-ce of employees in two selected companies in different departments. The primary focus is on sales representatives (sales), followed by logistics and project ma-nagers. The results of the ji-ne departments and the logistics and project ma-nagement department are primarily used for comparison with the sales depart-ment to see the individual differences. Secondary data are presented to get a gene-ral idea of stress in the workplace. A questionnaire survey was used to investigate stress on the job performance of employees in the selected companies. In the practical part, the research in the form of questionnaire survey is applied in two companies namely GPD a.s. and Bosch Rexroth company s.r.o. The departments are investigated, which are divided into logistics, sales and other departments in GPD a.s. and other departments in Bosch Rexroth company s.r.o., which are divided into other departments, logistics, sales and project management departments. The questionnaire survey analyses the relationship between stress load and work per-formance in the individual companies in each department and then compares the companies with each other. According to the results of the questionnaire survey, recommendations are proposed for sales representatives and certain departments of the selected firms to minimize the stress factors in the selected firms. The re-commendations can subsequently lead to higher performance of the selected firms and higher sales. The recommendations are based on the results of the survey for example, introducing courses and training to help separate work life from co-private life can help to arrange "time management" so that employees can schedu-le their work duties well. Other recommendations are better communication between departments in the form of providing clearer and more precise informa-tion to each other, inter-departmental meetings where possible ambiguities can be clarified or merging events for better workplace relations between depart-ments, such as 'team building' and others.
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Psychological and social aspects of healthcare personnel's work with a dying patient
Sláviková, Karolína ; Šivicová, Gabriela (advisor) ; Šturma, Jaroslav (referee)
The goal of this thesis, "Psychological and social aspects of healthcare personnel's work with a dying patient", is to examine the socially unattractive issue of dying. Despite the fact that dying is a natural process, we often treat it with contempt and concern. We inspect this topic through a prism of healthcare personnel view, who is in contact with dying and death on a daily basis. In the theoretical part, we have first described the concept of death from historical point of view and afterwards we have narrowed it down to psychological-medical view of dying. Next, we have introduced the area of lenitive care for a dying patient, which is closely related to the topic of euthanasia. Of course, in relation to euthanasia, we then talked about medical ethics. This way we have circled around the relationship between a medic and his patient, the specifics of their communication, and finally we have described the psychological stress of healthcare personnel, possible coping strategies and eventual defensive mechanisms. Bibliography also features current research, both domestic and foreign. In the empirical part, we have attempted to map and describe psychosocial aspects relevant to working with a dying patient, with emphasis on identifying stress factors and strategies for healthcare personnel to cope...
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Nursing students'stress factors in clinical practice
Kurišová, Miroslava ; Mádlová, Ivana (advisor) ; Javůrková, Alena (referee)
The thesis focused on the psychological burden of students on professional practice and the related self-confidence of students. I set myself the following goals: 1. To analyze the current state of the issue of mental stress of students in professional practice using scientific sources and articles in Czech and foreign literature 2. Prepare a non-standardized structured questionnaire and assign the target respondents - students of Charles University 2nd and 3rd Faculty of Medicine / Faculty of Medicine / in Prague and students of the Faculty of Health Care of the Catholic University in Slovakia 3. Identify potential differences in the identification of stressors in the course of professional practice and assessment of load by students 4. Propose recommendations for improving education and training during studies The methodology of the work will consist in the analysis of data obtained using a structured questionnaire, which will be distributed electronically among students of General Nursing in 2nd and 3rd year in Czech Republic and in the 2nd and 3rd year in Slovakia. The final number of respondents for both universities was 66, a rate of return of 72%. MS excel 2016 spreadsheet processor and IBM SPSS Statistics software version 22 (USA) and Statistica version 12 were used for data analysis. The...
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Study on metabolism of polyhydroxyalkanoates in bacterium Rhodospirillum rubrum
Pacasová, Viktorie-Alexandra ; Byrtusová, Dana (referee) ; Slaninová, Eva (advisor)
The present thesis focuses on polyhydroxyalkanoate (PHA) production in Rhodospirillum rubrum, comparing wild-type PHA-producing (R. rubrum) and mutant PHA-non-producing strains in terms of cell morphology. These bacterial strains were also subjected to selected stresses and the effect of PHA on the stress response was determined using advanced analytical techniques. The two strains used were first cultured under different conditions differing in light access, oxygen, culture time and substrate. The effect of culture conditions and PHA content on resistance to selected stressors - elevated temperature, osmotic stress and repeated freezing cycles - was then investigated. First, strains were cultured under aerobic conditions in the dark for 48 and 72 h. Viability of these samples was examined using a fluorescent probe (propidium iodide) by flow cytometry, while cell disruption was examined by electron microscopy. Furthermore, a similar experiment was performed in which the wild-type and mutant strains were cultured under microaerobic conditions in the light for 120 h to produce pigments (bacteriochlorophyll a and carotenoids). UV-VIS spectroscopy was used to determine the extracted pigments. The effect of culture time and conditions on the stress response was also determined for both bacterial strains by flow cytometry and electron microscopy. In the experimental part of the work, the ability to produce the copolymer P(3HB-co-3HV) was confirmed in a wild-type strain of R. rubrum. The hypothesis of the protective property of PHA granules when exposed to freezing cycles was also confirmed. In contrast, the protective function of PHA was not proven when exposed to osmotic stress.
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Optimization of cultivation conditions and production of metabolites by microalgae of the genus Desmodesmus and Scenedesmus in photobioreactors.
Kubalová, Michaela ; Mikulíková, Renata (referee) ; Szotkowski, Martin (advisor)
Nowadays, a lot of attention is being paid to the biotechnology industry. Within this industry, are with the help of microorganisms produced various useful substances, such as chlorophyll and carotenoids, which are important antioxidant substances, but also fatty acids, sterols and ubiquinone. This thesis is focused on the cultivation of selected strains of microalgae of the genus Scenedesmus and Desmodesmus. In the first part of the thesis, the algae strains and studied metabolites are described. In the second, experimental part, different types of alcohol were applied to the selected strains as stress conditions, with the aim of increasing the production of intracellular metabolites. Further, fermentor cultivation was carried out, in which a combination of two different alcohols was applied. Subsequently, cultivation using a flat-panel photobioreactor was also carried out, in which light with different wavelengths was used. Several chromatographic techniques were used for the analysis and the results of the analyzes are presented in the experimental part.
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