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Characterization of selected yeast strains from the environment
Bečková, Alena ; Omelková, Jiřina (referee) ; Vránová, Dana (advisor)
The aim of this bachelor thesis deals with identification type-yeasts, which were obtained from the Culture Collection SAV in Bratislava. The purpose is extension of yeast database in laboratory of Faculty of Chemistry, which is used by identification yeasts in samples taken from food or environment. Identification of yeasts was implemented by method PCR-RFLP. Obtained segment is located in area 5,8S-ITS and is defined by using primers ITS1 and ITS4. Restriction analysis was carried out by restriction endonucleasis HaeIII, HinfI, HhaI and TaqI. Chosen species were also tested for presence of extracellular lipasis. In this part of characterisation was used SpiritBlue Agar. The presence of blue colour is lost by activity of lipasis.
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Factors influencing the quality of red wine
Zechmeisterová, Lucie ; Vránová, Dana (referee) ; Omelková, Jiřina (advisor)
In my thesis, I focused on monitoring of microorganisms in the sample of red grape juice and on the interactions between yeasts, bacteria and filamentous fungi. Three different media were applied for the cultivation of microorganisms; firstly for monitoring of total volume of microorganisms, secondly for yeasts and third time for lactic acid bacteria. The indirect method was used for the determination of the amount of viable cells. This method consists in enumerating of visible macroscopic colonies grown up on agar plates. When the cells grew up, the forms of colonies were analyzed visually and the morphology of microorganisms was detected microscopically. The operating time of enzymes in grape juice in the production of red wine was monitored after application of commercial enzymatic preparation. The enzym action in grape juice was observed on the basis of the process of degradation of high – molecular substrate by enzymes through the use of Ubbelohd´s viscometer. The research findings provided a lot of knowledge about the occurance of microflora in the process of production of red wine. The commercial preparations added to grape juice played a significant role.
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Wine and changes its chemical parameters during production using the autochthonous yeasts
Fialová, Lenka ; Vespalcová, Milena (referee) ; Vránová, Dana (advisor)
This bachelor's thesis deals with chemical changes in must during fermentation using autochthonous yeast. The theoretical part describes history of viticulture, morphology and chemical composition of wine grapes. There is also discussed technology of wine production and some of the principles of analytical methods used for chemical analysis of wine. The experimental part deals with principles of methods used for all analyses in this work and the results of said analyses. Parameters assessed in this thesis were concentrations of reducing sugars, ethanol and titratable acids and pH value. The analyzed must was obtained from Grüner Veltliner grape wine varietal.
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The influence of microflora on the sensoric characteristic of the wine
Petrášová, Ludmila ; Vítová, Eva (referee) ; Vránová, Dana (advisor)
The bachelor thesis is focused on the influence of the microflora on the sensory characteristics of the wine. The theoretical part provides information of the botanical description of Grüner Veltliner grape wine varietal, as well as its chemical composition, the white wine processing technology, and the influence of yeast on the aroma profile of this varietal. The experimental part describes the method of determining the aroma-active compounds by gas chromatography in combination with solid phase micro-extraction (SPME-GC). The object of the study was to measure samples of four different cider varieties of Grüner Veltliner during the fermentation process, and to compare the aromatic compounds in the cider with the indigenous yeast and in the cider where spontaneous fermentation was used.
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Characterization of selected yeast strains from food
Ostrihoňová, Katarína ; Vítová, Eva (referee) ; Vránová, Dana (advisor)
This bachelor´s thesis is focused on identification of yeasts of the cheeses by PCR-RFLP method and verifying the lipolytic activity of the yeast. In the theoretical part are processed basic information about yeast, their possible positive and negative effects on the quality of cheeses, the technology of production of cheeses, lipolysis and proteolysis in the cheese and of course of PCR-RFLP (The polymerase chain reaction-restriction fragment length polymorphism). Experimental section shows the isolation of DNA, identification of DNA by PCR made by amplification 5,8S-ITS sections of DNA using primers ITS1 and ITS4. The amplified DNA was purified by ethanol and then was subjected to restriction analysis with the enzymes HaeIII, HinfI, HhaI, TaqI. Then there is listed detection of the PCR product and the restriction fragments by gel electrophoresis. Lengths of the fragments obtained after electrophoresis will be used to identify yeast species isolated from cheeses. In the second part of the thesis in the experimental part we have dealt with evidence of lipolytic activity of the yeast by test on Spirit blue agar.
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Monitoring of changes of chemical parameters in wine production
Dlapalová, Kristýna ; Vespalcová, Milena (referee) ; Vránová, Dana (advisor)
This bachelor work deals with chemical ganges of the wine must during the fermentation process. We compered the sample must with addend commercial yeasts and indigenous yeasts. The theoretical part describes the vine and its variety. The variety Saugvinon is central of this work and it is more described.. The theoretical part describes the structure of grape and its chemical technology of wine production and wine disease. The production technology is divided into different steps of the production (eg. picking the grapes, pressing, fermentation and wine training). The experimental part describes the methods used in the determination of chemical parameters including the chemicals and equipment. The results are summarized the results of the determination of reducing sugars, titratable acidity, alcohol and pH must. The results are evaluated and commented upon in the discussion.
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Industrial production of ethanol
Flajs, Roman ; Zichová, Miroslava (referee) ; Omelková, Jiřina (advisor)
This bachelor thesis deals with ethanol production for food and car industry. The aim of this work is to give a summary of different kinds of raw material especially lignocelluloses and microorganisms used for its processing and fermentation. The thesis focuses especially on technological process of ethanol production and the utilization of different materials for fuel production.
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Use of diffrent nutrition source by selected carotenogenic yeasts
Čačková, Katarína ; Starečková, Terezie (referee) ; Márová, Ivana (advisor)
Carotenoids are the most common naturally occurring terpenoid pigments. Because of their positive biological functions, carotenoids represent a group of important molecules for the pharmaceutical, chemical, food and feed industries. This work was realized as a comparative study focused on use of some waste substrates as nutritional sources for production of carotenoid pigments by red yeast Rhodotorula aurantiaca. Yeast were cultivated in different media with selected waste substrates – apple fiber, whey, wheat etc. To some media hydrolytic enzymes prepared from some fungal strains were added. Most of waste substrates seems to be useful for R. aurantiaca cultivation. As the best nutritional sources for enriched biomass and carotenoid production apple fiber or wheat processed by mixed preparative of extracellular hydrolases from Fusarium solani were found.
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Production of carotenoids by red yeasts grown on some waste substrates
Kubáčková, Martina ; Čarnecká, Martina (referee) ; Márová, Ivana (advisor)
Carotenoids belong to the most widespread and abundant classes of natural pigments with utilised in food industry, pharmacy and cosmetics. Presented work was realized as a comparative study of some substrates for cultivation of red yeast Rhodotorula glutinis, which produces carotenoid pigments. Yeasts were cultivated in different media with several waste substrates (for example potato fiber, apple waste, cereals, grains, etc.) as nutrition sources. To some substrates hydrolytic enzymes isolated from the fungi genus Fusarium were added. Majority of waste substrates were acceptable for cultivation. However, the best conditions for production of carotenoid enriched biomass (6,4 g/l of biomass enriched 3,2 mg /g of beta-carotene) exhibited media with hydrolytic fungal enzymes.
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Comparison of PCR methods suitable for identifikation of yeasts in foodstuffs.
Zovčáková, Monika ; Márová, Ivana (referee) ; Vránová, Dana (advisor)
This bachelor´s thesis deals with identification of yeasts by PCR method in foods. It includes basic information about yeast´s cell. There are elaborated molecular methods of yeast identification. Yeasts are crucial agents in many important natural and industrial bioprocesses as well as in spoilage of foods. Classical methods include morphological and biochemical tests, which are time consuming. The rapid detection and identification of yeasts is necessary for assessment of their beneficial and harmful roles in the production and spoilage of foods.
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