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Kvasinky jako součást mikrobioty osidlující potravinové suroviny a potraviny
Ferbyová, Kateřina
In the literary research this thesis summarizes general information about the yeast genera, including cytology, morphology, and physiology of the cell. Yeasts are being classified within taxonomy. Some of the most important genera found and used in the food industry are characterized. Theses then describes both the cultural and contaminating microbiota of main food groups. Lastly, the paper describes some commercially used preservation techniques. The experimental part of this thesis is focused on assessing total microbial count (TMC) and yeast and mold count in two samples of spontaneously fermented beer as well as two samples of wine with different treatment. This is to capture the natural microbiota of these alcoholic beverages. In the case of yeast and mold count, samples were inoculated in chloramphenicol yeast glucose agar, in the case of TMC the plate count agar (PCA) was used. Found yeast was reinoculated in order to obtain a pure culture strain. Yeasts were identified using a CANDIDA-screen set (Erba-Lachema). C. glabrata, C. krusei, C. lipolytica and S. cerevisiae were found. Molds have been found on PCA. They were isolated and identified under microscope based on their morphological features. 3 Penicillium molds and 1 Aspergillus mold were identified.
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Antagonistic regulation by global transcription factors Tup1p, and Cyc8p of Flo11 and Flo11 -dependent phenotypes in wild yeast
Nguyen Van, Phu ; Palková, Zdena (advisor) ; Heidingsfeld, Olga (referee) ; Malcová, Ivana (referee)
Biofilms are a common mode of yeast growth in which cells adhere to each other and adhere to abiotic surfaces to form complex multicellular structures. Living together in biofilms provides cells with several beneficial features compared to planktonic cells. Undoubtedly, protection and resistance are advantages of life inside colony biofilms. Biofilms are found in many environments and play many important roles in commercial industries. However, biofilms can also be extremely dangerous in clinical settings. There is thus great interest in studying biofilms and how to eliminate them. In this study, we used wild yeast Saccharomyces cerevisiae colony biofilm as an ideal system to investigate potential functions of the yeast Cyc8-Tup1 transcriptional corepressor complex in the regulation of yeast adhesion, and biofilm formation on agar and at solid-liquid interfaces. Unexpectedly, we have found that Cyc8p and Tup1p antagonistically control the formation of structured biofilm colonies on agar and FLO11 expression. Cyc8p itself acts as a key repressor of FLO11, whereas Tup1p promotes the formation of biofilm colonies and induces FLO11 expression by inhibiting the repressive function of Cyc8p and preventing Flo11p degradation possibly by inhibiting an extracellular protease. In addition, other features...
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Antagonistic regulation by global transcription factors Tup1p, and Cyc8p of Flo11 and Flo11 -dependent phenotypes in wild yeast
Nguyen Van, Phu ; Palková, Zdena (advisor) ; Heidingsfeld, Olga (referee) ; Malcová, Ivana (referee) ; Demnerová, Kateřina (referee)
Biofilms are a common mode of yeast growth in which cells adhere to each other and adhere to biotic and abiotic surfaces to form complex multicellular structures. Living together in biofilms provides cells with several benefits, compared to planktonic cells such as protection and resistance to antimicrobials, environmental stresses and host immune attacks. Biofilms may play many important roles in commercial industries. But they are considered to be extremely dangerous in clinical settings. There is thus great interest in studying biofilms and how to eliminate them. In this study, we used wild yeast Saccharomyces cerevisiae colony biofilm as an ideal system to investigate potential functions of the yeast Cyc8p-Tup1p transcriptional corepressor complex in the regulation of yeast adhesion and biofilm formation on agar and at solid-liquid interfaces. Unexpectedly, we found that Cyc8p and Tup1p antagonistically control FLO11 expression and the formation of structured biofilm colonies on agar. Cyc8p itself acts as a key repressor of FLO11 and biofilm colony formation, whereas Tup1p promotes the formation of biofilm colonies and induces FLO11 expression by inhibiting the repressive function of Cyc8p and preventing Flo11p degradation possibly by inhibiting an extracellular protease. Other typical features...
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Antagonistic regulation by global transcription factors Tup1p, and Cyc8p of Flo11 and Flo11 -dependent phenotypes in wild yeast
Nguyen Van, Phu ; Palková, Zdena (advisor) ; Heidingsfeld, Olga (referee) ; Malcová, Ivana (referee)
Biofilms are a common mode of yeast growth in which cells adhere to each other and adhere to abiotic surfaces to form complex multicellular structures. Living together in biofilms provides cells with several beneficial features compared to planktonic cells. Undoubtedly, protection and resistance are advantages of life inside colony biofilms. Biofilms are found in many environments and play many important roles in commercial industries. However, biofilms can also be extremely dangerous in clinical settings. There is thus great interest in studying biofilms and how to eliminate them. In this study, we used wild yeast Saccharomyces cerevisiae colony biofilm as an ideal system to investigate potential functions of the yeast Cyc8-Tup1 transcriptional corepressor complex in the regulation of yeast adhesion, and biofilm formation on agar and at solid-liquid interfaces. Unexpectedly, we have found that Cyc8p and Tup1p antagonistically control the formation of structured biofilm colonies on agar and FLO11 expression. Cyc8p itself acts as a key repressor of FLO11, whereas Tup1p promotes the formation of biofilm colonies and induces FLO11 expression by inhibiting the repressive function of Cyc8p and preventing Flo11p degradation possibly by inhibiting an extracellular protease. In addition, other features...
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