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Vplyv asimilovatelného dusíka na produkciu prchavých kyselín v priebehu alkoholovej fermentácie
Maťas, Ján
This master work was focused on fermentation of a grape wine must and production of volatile acids by yeast. Work in theoretical part deals with assimilation substances available for yeast with focus on a nitrogen compounds. Its content's in grape must and impact on a fermentation process. Furthermore, the work described in the possibility of creation of acetic acid and the possibility of its elimination from the must and wine. At the end of the theoretical section lists the types of yeast nutrition with a detailed description and uses. The practical part is focused on experiments conducted on Faculty of Horticulture, Mendel University. The experiment was composed of 10 variants, and each variant was used by another dose of a different kind of nutrition. Progress has been observed to form acetic acid and decrease the assimilation of substances. Of all the variants was the most different option 0 for which he was also a different view changes assimilable nitrogen
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Role of the low-molecular metabolites in the development of yeast colonies
Bezdíčka, Martin ; Palková, Zdena (advisor) ; Dostál, Jiří (referee)
Previous research of colonies formed by yeast Saccharomyces cerevisiae growing on glycerol agar medium revealed two major cell types of U and L cells that are formed within these colonies. This colonial cell differentiation seem to be caused by communication among yeast cells as well as whole colonies and affected by changes in the environment (for example changes in nutrients). Studies of U and L cells showed that U cells are more resistant against biological, chemical and physical stresses than L cells. The aim of this thesis was to isolate U and L cell types and investigate their resistance against selected low molecular weight chemical substances produced in Ehrlich pathway. Ehrlich pathway was discovered in 1907 and was classified as amino acid catabolic pathway in yeast S. cerevisiae. The low molecular intermediates are formed in Ehrlich pathway which are called fusel (original name from German) alcohols and acids. These chemical substances are widely used in food industry and cosmetics especially because of their aroma. Several studies provided indications that these chemical substances may affect development of colonies and important yeast functions such as switching to the pseudohypfal growth of S. cerevisiae cells. Some chemical substances of the Ehrlich pathway were selected and their effects on...
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Vplyv asimilovatelného dusíka na produkciu prchavých kyselín v priebehu alkoholovej fermentácie
Maťas, Ján
This master work was focused on fermentation of a grape wine must and production of volatile acids by yeast. Work in theoretical part deals with assimilation substances available for yeast with focus on a nitrogen compounds. Its content's in grape must and impact on a fermentation process. Furthermore, the work described in the possibility of creation of acetic acid and the possibility of its elimination from the must and wine. At the end of the theoretical section lists the types of yeast nutrition with a detailed description and uses. The practical part is focused on experiments conducted on Faculty of Horticulture, Mendel University. The experiment was composed of 10 variants, and each variant was used by another dose of a different kind of nutrition. Progress has been observed to form acetic acid and decrease the assimilation of substances. Of all the variants was the most different option 0 for which he was also a different view changes assimilable nitrogen
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Eliminace kyseliny octové kvasinkami během "kvašení přes čtyři"
Sekanina, Jan
The theme of this work is a method of refermentation wine at 4% alcohol by volume, focusing on the elimination of acetic acid or during fermentation. This is the old method, which is used to correct the volatile wines. The introduction describes the alcoholic fermentation. Further disclosed are methods of inoculation, pathways of acetic acid, both in the vineyard and in the winery. Part of the work is devoted to the ability of yeast to eliminate acetic acid. She is also sensory evaluation of wines. The practical part is devoted to refermentation of volatile wine with musts in the varieties Pinot Blanc and Lemberger, the disappearance of acetic acid during fermentation.
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Současné možnosti výroby octa a jeho uplatnění v potravinářství
Rumíšková, Soňa
The aim of this thesis was to develop a literature review on the topic: Technology of vinegar. Vinegar can be made by several methods; these methods are explained in the thesis. The most widely used method nowadays is the submerged method which is also the most modern methods. Raw materials used for the vinegar production are discussed in next section; special attention is paid to ethanol as the main raw material. Then the thesis focuses on factors that may affect the formation of acetic acid, the defects that may occur in the vinegar and finally the microorganisms that cause acid fermentation. Following section covers story of a particular company that produces vinegar in Bzenec, named OKL Bzenec, which describes the company's history, manufactured products and applied work standards.
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Organical chemicals from biomass
DOLEŽAL, David
This bachelor thesis deals with the processes of biomass as a renewable resource for the production of chemicals that could compete chemicals obtainable from fossil sources. Processing of biomass can be divided into two main approaches namely a thermochemical and biotechnological processing of biomass processes. This processing involves many processes such as hydrolysis, crushing, fermentation, combustion or high temperatures and pressures, and many other thermochemical or biotechnological processes associated with the nature of the structure of the biomass. As the most important products of biomass processing can be considered biofuels represented in my work mainly by ethanol, but also methanol and other organic chemicals such as furfural, levulinic acid and hydroxymethylfurfural derived from the processing of C5 and C6 sugars located in the fundamental structure of biomass. These organic chemicals can also serve as a chemical platform and subsequent modifications of them can get products with the same or very similar properties of the products of the petrochemical industry.
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