National Repository of Grey Literature 92 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
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.
Diversity, ecology, and biotechnological potential of yeasts associated with bark beetles
Havlíček, Václav ; Kolařík, Miroslav (advisor) ; Novotný, David (referee)
Bark beetles (Coleoptera; Scolytinae) attack woody plants, which is why they are considered pests from a human perspective. They owe their evolutionary success, among other factors, to numerous symbioses with microorganisms, with fungi playing a significant role. The mycobiome of bark beetles is dominated by yeasts, which, nevertheless, are widely overlooked. Intestinal yeasts not only from Ips typographus but also from other species of bark beetles have potential for future biotechnological applications. The aim of this study was to examine their diversity and physiological activities, which will help clarify their ecological role and biotechnological potential. Collections were conducted in the Czech Republic from larvae of the spruce bark beetle Ips typographus and from various species of subcortical insects in Kenya. Yeasts were identified and taxonomically classified based on rDNA sequencing. A total of 133 yeast strains belonging to 37 species were identified, including 9 species that could not be identified and belong to previously undescribed species and in two cases also genera. A total of 133 yeast strains belonging to 37 species were identified, including 9 species that could not be identified and belong to previously undescribed species and in two cases also genera. The most frequently...
Searching for interaction partners associated with the transcriptional apparatus of yeast linear plasmids
Ľalíková, Kristýna ; Vopálenský, Václav (advisor) ; Čáp, Michal (referee)
The pGKL plasmids are a type of yeast linear double-stranded DNA plasmids found in the cytoplasm of yeast Kluyveromyces lactis. The plasmid gene transcription process involves the plasmid transcription apparatus, which shows similarity to the transcription apparatus of poxviruses. Poxviruses cause a range of serious diseases. Thus pGKL plasmids offer a safe way to study some of the mechanisms of these viruses without the risk of infection. The plasmid transcription apparatus comprises non-canonical RNA polymerase, helicase, and capping enzyme as its main components. Although RNA polymerase has been thoroughly characterized and described, little focus has been on the interactions between proteins within the transcription apparatus. Therefore, this study aims to shed light on this fundamental aspect of the gene expression of pGKL plasmids. The main goal of the thesis was to prepare a system that would facilitate the search for interaction partners of the pGKL transcription apparatus and verify the interactions between chosen proteins in yeast cells. The foundation of this system relies on the use of optimized genes and the yeast two-hybrid system method. The development of the experimental method has begun successfully, and it's expected to conclude soon, although further optimizations are still...
Co-cultivation of carotenogenic yeasts and cyanobacteria on selected food wastes
Kodajek, Matěj ; Márová, Ivana (referee) ; Szotkowski, Martin (advisor)
Cyanobacteria and yeast are microorganisms, that are cultivated in the biotechnological industry to produce biomass. Biomass contains several organic substances, that are used in the food, pharmaceutical or energy industries. This thesis deals with the joint cultivation (co-cultivation) of cyanobacteria and yeast on food waste. The cyanobacteria Synechococcus nidulans, Synechococcus bigranulatus, Anabaena torulosa and Spirulina were used for co-cultivation with yeast Rhodotorula kratochvilovae and Rhodotorula toruloides. Cultivation media included following food wastes: coffee oil, hemp oil, frying oil, molasses, molasses hydrolyzate, whey, whey hydrolyzate and waste glycerol. In the theoretical part is a comprehensive literature research focused on cyanobacteria, yeasts, and their specific genera, monitored metabolites, co-cultivation, food waste and analytical methods. The experimental part contains a list of used chemicals, devices, aids, strains, and descriptions of procedures for the cultivation of microorganisms, isolation, and analysis of biomass. The aim of the thesis was to do screening cultivations, to find suitable strains of microorganisms for symbiotic co-cultivation and to find a suitable food waste. Following co-cultivation in a semi-operational laboratory bioreactor. Analysis the obtained biomass using gas and liquid chromatography and evaluation the results.
Srovnání pivovarských a vinných kmenů kvasinek v různých fermentačních podmínkách
Ryšavý, Daniel
The thesis on the topic Comparison of brewer’ and wine’ yeast strains in various fermentation conditions has been prepared at the Department of Postharvest Technology of Horticultural Products at the Faculty of Horticulture, Mendel University in Brno in 2019/2020. The thesis deals with the taxonomy and the properties of yeasts and their useage and focuses mainly on brewer's and wine yeast strains. In the practical part, the analytical parameters of wort fermented by selected brewer's and wine yeast strains have been evaluated and compared. By these yeasts their influence on the sensory quality of the produced beer has also been evaluated.
Studium inhibice vinařských kvasinek
Koublová, Vendula
The theoretical part of the thesis summarizes the basic microbiological and oenological knowledge about significant wine yeasts. It deals with genera of yeasts that are part of the vine microbiome and can participate in fermentation. The benefits and disadvantages of autochthonous yeasts in fermentation are discussed, along with some commercial products with non-Saccharomyces yeasts available on the market. The experimental part of the thesis evaluates the in vitro effect of pyrosulfite use on two selected strains of Saccharomyces cerevisiae and three strains of Saccharomyces bayanus. Furthermore, the in vitro effect of pyrosulfite was tested on three strains of wine-related bacteria: Lactobacillus brevis, Pediococcus damnosus, and Acetobacter aceti. The disk diffusion method, the growth curves method in full medium, and the growth curve method in biochemical tests were used.
Raw materials for beer production - history and present and their benefits for human health
NOHEJL, Vlastimil
This bachelor's thesis outlines the evolution of brewing from its outset to the present time. The aspects of production, processing, division, and composition of raw brewing materials are described in detail as well as the possibility of using alternative plant components to create non-traditional beers. The next chapter outlines the process of beer production with the emphasis on the individual technological operations and the importance of mashing temperatures. Since beer is a natural, nutritionally rich, fermented beverage, the final part of the thesis examines its health benefits.
Dynamics of yeast plasma membrane domains
Oláhová, Dominika ; Zahumenský, Jakub (advisor) ; Vopálenská, Irena (referee)
Plasmatic cellular mebrane consists of specialized domains which differ in shape, function and size. This compartmentalization allows cells to coordinate and separate a large number of diverse processes. Disorders of cell organization at the level of membrane domains are increasingly associated with the expansion of pathological disorders. Microdomains also play a role in the virulence of pathogenic organisms, e.g. some types of yeast. One of the best described microdomains of the yeast plasma membrane is the MCC (membrane compartment of arginine permease Can1), which is stabilized by a protein complex called the eisosome. The composition of the MCC/eisosome is described in detail, the dynamics of the individual components in the basal state (i.e. without stress) has not yet been described. The aim of this thesis is to summarize current knowledge about the dynamics of the proteins of this microdomain and its relationship with other domains of cell membranes through a detailed review of the available literature. And at the same time by using the advanced fluorescence method FRAP (fluorescence recovery after photobleaching) to show in my own experiment that in the basal state there is an exchange of individual Nce102 molecules in the MCC/eisosome microdomain. Key words: yeast, plasma membrane,...
Use of stress factors for the production of lipid substances by yeasts of the genus Metschnikowia
Tručková, Marie ; Márová, Ivana (referee) ; Němcová, Andrea (advisor)
This Master´s thesis consists of two parts. The theoretical part is focused on the influence of various stress factors in the cultivation process, such as osmotic stress, oxidative stress, dehydration, cultivation time, pH or temperature on yeasts of the Metschnikowia genus. The practical part deals with osmotic and oxidative stress. Oxidative stress was performed under two different conditions (various cultivation time and temperature). The properties of yeast production were monitored mainly by gas chromatography and marginally also by flow cytometry. The analysis was performed for Metschnikowia pulcherrima, Metschnikowia andauensis, Metschnikowia chrysoperlae, Metschnikowia sinensis, Metschnikowia zizyphicola and Metschnikowia shanxiensis strains. The results showed that both oxidative stress and osmotic stress induce better lipids production. The amount of lipids, especially the fatty acid composition, also varied depending on the strains studied and the culture conditions used. The production of unsaturated fatty acids was further demonstrated in this work. The most suitable medium for the production of lipids and unsaturated fatty acids was the salt medium. It is clear that yeasts of the genus Metschnikowia are highly adaptable yeasts. Therefore, they might be potentially auspicious biotechnology producers.
Use of molecular techniques to characterize yeasts of the genus Metschnikowia
Schneiderwindová, Nicole ; Brázda, Václav (referee) ; Němcová, Andrea (advisor)
This diploma thesis deals with the possibilities of implementation and use of molecular methods for the characterization of yeasts of the genus Metschnikowia and the application of methods in biotechnology or the food industry. The theoretical part focuses on a brief description of yeast, specially selected species that were used during the practical part of the work, the possibilities of their use, and especially on a detailed description of all molecular techniques used. The practical part focuses on the optimization of the molecular methods, namely the method of pulsed gel electrophoresis and the method of denaturing gradient gel electrophoresis. Initially, yeast was cultured under optimal conditions that are specific to this genus. Furthermore, their DNA was isolated using isolation techniques, which were subsequently processed using PFGE and PCR–DGGE methods. The DNA isolation procedure needed to be optimized the most. Several optimizations of the concentration of lysis enzymes, especially the lyticase enzyme, were performed. It was also necessary to determine the correct ratio of low-melting agarose and isolated DNA, which was essential for the correct consistency of the isolated DNA blocks and their further application in PFGE analysis. Finally, the PFGE method was optimized, which brought the correct distribution of chromosomes, and it was possible to describe the individual chromosomes according to their size according to the standard used CHEF of the yeast Hansenula wingei. To properly optimize the DGGE analysis process itself, it was first necessary to isolate the yeast DNA using a kit, then it was used as a template for the PCR reaction. The annealing temperature was also optimized for the individual groups of primers. The amplicons obtained by this reaction were separated by the DGGE method. This technique mainly required the optimization of basic parameters such as the range of the denaturation gradient or the total separation time. According to the measurement results, it can be determined that the process of yeast DNA isolation and their subsequent analysis using molecular methods of pulsed gel electrophoresis and denaturing gradient gel electrophoresis was successful. We were able to describe the genome and determine the number of chromosomes in all used yeast species of the genus Metschnikowia at least partially.

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