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Production of biologically active substances by yeasts and algae cultivated on different nutrition sources
Kohútová, Darina ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
Carotenoids are lipophilic pigments and the most widespread antioxidants occurring in nature with great application potencial in the cosmetics, pharmaceuticals and food industry. Lipids are one of the essential organic substances of living organisms as a nutrition source and energy supply. This work deals with the optimalization of nutritional characteristics of cultivation medium for cultivation of carotenogenic yeasts and algae. Two waste substrates were used and different nitrogen sources, NaCl concentrations, and various C/N ratios were applied. The biomass obtained was analysed by chromatography, and the production of carotenoids, ergosterol, coenzyme Q and lipids was evaluated. Of the tested nitrogen sources urea was the most favourable for yeasts, and sodium nitrate for algae. Higher salt concentration had a negative effect on yeast growth but increased degree of fatty acid unsaturation. Tested C/N led different effects: while the C/N ratio 16 most suitable for growth, the increasing C/N ratio caused the increase of the polyunsaturated fatty acids content. Of the used yeast strains, Rhodotorula mucilaginosa and Sporidiobolus salmonicolor exhibited the best production characteristics, of the used algae strains, it was Chlorella.
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The antimicrobial effects of plant extracts against yeast skin mycoses
Posztósová, Gyöngyi ; Rapta, Marek (referee) ; Němcová, Andrea (advisor)
Superficial cutaneous mycoses are relatively widespread and affect more and more people. Currently are used drugs as ketoconazole, fluconazole and others to treat mycoses. Pathogens occasionally become resistant to these drugs. Medicinal plants have a long history in alternative medicine and they could be a good solution. This bachelor thesis deals with the study of antifungal activity of selected plants. Were prepared ethanol extracts of basil, betony, eucalyptus, turmeric, geranium, oregano and ginseng. The theoretical part of thesis contains a review of the most frequently occurring dermatomycoses. It describes plants as sources of natural substances with antimicrobial effect and the content of selected active substances. The experimental part is focused on the analysis of plant extracts. Was determined the content of total polyphenols, flavonoids and antioxidants. The antimicrobial activity was monitored against yeast Candida glabrata and against G- and G+ bacteria, specifically Escherichia coli and Micrococcus luteus. Finally, the cosmetic products with the addition of plant extract were prepared and tested against mycoses.
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Role of autophagy in yeast cell adaptation
Brádlerová, Michaela ; Kuthan, Martin (advisor) ; Zikánová, Blanka (referee)
Autophagy is an evolutionarily conserved degradative pathway. Autophagy occurs constitutively at a basal level and it is involved in the recycling and turnover of damaged or superfluous organelles and proteins. It has a critical role in cellular homeostasis. Autophagy can be induced in response to starvation or other types of stress. Induction of autophagy during these conditions has a major role in protection and adaptation of the cell. Autophagy needs to be properly regulated. A wide range of diseases is associated with dysregulation of autophagy. Better understanding of autophagy mechanisms can help to develop strategies designed to modulate autophagic responses occuring in a number of diseases. This work is focused on current knowledge of main types of autophagy and how autophagy helps yeast cells to adapt. Key words: autophagy, yeast, degradative pathway, adaptation, TORC1
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Regulation of yeast chronological ageing
Némethová, Ema ; Palková, Zdena (advisor) ; Motlová, Lucia (referee)
Yeast cells are able to differentiate during chronological aging and form different cell- types which acquire different viability. Chronological aging cells do not divide and thus mimic the aging of cells within multicellular organisms, such as mammals. Understanding of mechanisms of chronological aging of yeasts thus could help to understand similar processes of more complex organisms. Two types of cells, called "quiescent" and "non- quiescent" cells, are formed when yeast are grown in liquid medium. These cells have different morphology and gene expression and also differ in their metabolism. Yeast cells within agar-plate-grown colonies can sense different gradients of nutrients and signaling compounds and diversify to different cell types such as U and L cells, located in different colony regions. Both the "quiescent" and U cells are more vital and able to proliferate, whereas "non-quiescent" and L cells are less viable and exhibit stress features. Chronological aging involves many cellular processes including accumulation of storage compounds, mitochondrial activity, functions of specific genes and can be affected by calorie restriction and mild stress. Key words: chronological aging, yeast, differenciation of cell populations, metabolic change
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Inducible promoters and their use in yeast cell manipulation
Přibáňová, Gabriela ; Palková, Zdena (advisor) ; Vopálenský, Václav (referee)
Promoters which can be regulated by different chemical or physical factors are often used in cell manipulations. This thesis focuses predominantly on promoter systems which use light as an inductor. There are two main approaches to controlling a promoter by light. The first one uses so-called "caged molecules", chemical inducers whose inducing activity is "masked" by a photolabile protecting group. The second approach includes optogenetic systems, which can regulate transcription in cells. These systems are encoded in the DNA of the organism, and light is the only external regulatory stimulus. Photoreceptors that need a specific cofactor (chromophore) are the main components of optogenetic systems. There are several groups of photoreceptors classified by the type of chromophore and photoactivation mechanism. This thesis gives an overview of optogenetic systems used for transcription regulation and focuses on different photoreceptors and induction mechanism used. The systems using photocaged molecules are described as well. Furthermore, the thesis deals with light- systems in yeast as a model organism as well as organism used for biotechnological purposes. Finally, some limitations of light inducible promoters are discussed, including the chromophore type, the wavelength of the light, and the...
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The analysis of membrane potential recovery in yeast under CCCP-induced stress
Babuka, David ; Plášek, Jaromír (advisor)
The master's thesis is focused on the study of response of the intracellular pH of the yeast cells on various external environments, primarily in a relation to the protonophore carbonyl cyanide m-chlorophenylhydrazone, CCCP. To measure the intracellular pH of the yeast cells we used a genetically coded fluorescent probe the ratiometric pHluorin. Using the method of synchronously scanned fluorescent spectra we were able to measure the intracellular pH of the cells with high precision. As a part of these experiments we also studied the influence of ionic strength of the cell suspensions buffers on the surface potential as well as the influence of the mineral salt KCl on the depolarization of the yeast membranes and cytosolic acidification induced by the protonophore CCCP. We examined the changes of cytosolic pH as such but we also used the measured pH as an indicator of the processes and the state of environment outside the cell. One of the most notable outcomes of this thesis is a new method of monitoring the value of the surface potential of the yeast cells by measuring the titration curves of cytosolic acidification induced by the protonophore CCCP.
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Production of carotenoids grown on waste fat
Holub, Jiří ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
Carotenoids are lipid-soluble pigments which are contained in plants and microorganisms. Carotenoids are known for their antioxidant effects. Lipids are predominantly non-polar substances, which are essential and present in all types of organisms. The research was made by theoretical and practical form. It was dealing with production of carotenoids pigments and different lipophilic substances by yeasts of Rhodotorula glutinis, Rhodosporidium toruloides and Sporidiobolus metaroseus, cultivated in media containing waste fat or glycerol. Further, methods for obtaining lipid substances from microorganisms and with further analysis of samples by gas or liquid chromatography were optimized. The main task of the research was to find out which types of media and yeasts are the most suitable for production of lipid substances. For production of lipid substances in glycerol media, as the best producing strain Rhodosporidium toruloides was found, which simultaneously reported the highest concentrations of carotenoids on fatty and fatty hydrolyzed media.
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Production of beta-glucans by some yeasts and algae
Veselá, Markéta ; Kočí, Radka (referee) ; Márová, Ivana (advisor)
Several yeast strains and microalgae were selected for this diploma thesis. -glucans, lipids, carotenoids, ergosterol and coenzyme Q were determined in selected producers, and the cultivation conditions for yeast strains were optimized to gain enhanced production of -glucans. Microalgae cultivations were carried out according to the instructions of the Collection of Autotrophic organisms (CCALA). Selected microalge strains include Desmodesmus acutus, Dunaliella salina, Arthrospira maxima and Cyanothece sp. Selected yeast species include Rhodotorula glutinis, Cystofilobasidium macerans and Sporidiobolus metaroseus. Edible yeast Saccharomyces cerevisiae was cultivated to compare with other yeast strains because of it's verified production of -glucans. -glucans were then determined by the enzymatic kit K-YBGL Megazyme, carotenoids, ergosterol and coenzyme Q were analyzed by HPLC/PDA and fatty acids were analyzed by GC/FID. The best producer of yeast -glucans was R. glutinis and S. metaroseus, and the best conditions for the production of -glucans and other metabolites was the C/N ratio of 70. Within the microalgae species, only -glucan production was observed, the best producer was D. acutus.
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Study of the chemical processes during kombucha technology
Chludilová, Markéta ; Obruča, Stanislav (referee) ; Pořízka, Jaromír (advisor)
The kombucha drink is referred to as leavened tea with added sponge called a scobie. In this way, a low-alcohol beverage is obtained, which gains considerable popularity, especially due to the alleged beneficial properties for human health. The microbial composition of this beverage is very rich, consisting of bacteria and yeasts living in a beneficial symbiosis [11]. The microbial composition of the drink and its beneficial effects on human health are very closely related. This work deals with the analysis of the chemical composition of the commodity beverage, especially with regard to the content of major components such as organic acids, carbohydrates and ethanol. These analytes are among the most common and most profoundly found substances in the carbohydrate beverage and are very closely related to the microbial composition of the scoby itself [3]. Combo beverage samples were supplied by RebornFood, one of which is the commercial production of this drink on the Czech market. At the same time, this company bases itself on purely natural fermentation of beverages, and therefore it is not particularly involved in the production process. The results of this diploma work point to the effect of the scoby used and the associated occurrence of analytes in the beverage, as well as the production process associated with the formation of analytes, which is described in several articles. It is expected that this work will provide information both on the production conditions and on the chemical properties of the beverage related to the condition of the scoby, which will be used further, both for RebornFood and the material used to solve the technical problems of this beverage production.
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Influence of raw materials on qualitative indicators of various types of craft beer
HEJTMÁNKOVÁ, Zdeňka
Abstract The Bachelor's Thesis considers basic ingredients necessary for producing beer. In the first part, raw materials like hop, brewer's yeast, water, malt and its substitutes are dealt with. Regarding hop, the seed cone along with its chemical composition is discussed. Significant varieties grown in the Czech Republic are mentioned as well as selected foreign varieties of hop. Not least, packaging and storage of hop is described. Similarly with malt, where types of malt are listed and evaluation of quality given. The thesis contains also types of water suitable for producing beer. An indispensable ingredient for production of beer is brewer's yeast differentiated as top-fermenting and bottom-fermenting yeast. As an aside, the chemical composition and propagation of yeast is mentioned. In the last part, sorts of craft beer are discussed focusing on qualitative indicators of certain sorts of beer.
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