National Repository of Grey Literature 115 records found  1 - 10nextend  jump to record: Search took 0.02 seconds. 
Interaction of yeast and microalgae extracts with cell cultures
Serikbay, Adilkhan ; Holub, Jiří (referee) ; Márová, Ivana (advisor)
The objective of this bachelor thesis was to optimize the extracting of bioactive compounds from microorganisms for the purpose of characterizing and evaluating their cytotoxicity on human cell line HaCaT. During the characterization phase, extract samples were analyzed using spectrophotometric techniques. After exposing the cell line to selected extracts, a cytotoxicity test was performed to assess cell viability using MTT analysis. The theoretical part encompassed an extensive literature review focused on cultivation techniques, human cell lines, cytotoxicity analysis, and viability assessments. The practical section provided a detailed exploration of contemporary extraction techniques utilizing a wide range of both polar and non-polar solvents to enhance the efficiency of extracting active compounds from the yeast strain Rhodotorula toruloides and microalgae Chlorella vulgaris. Active compounds such as ubiquinone, ergosterol, lycopene, and torularhodin were identified in the yeast, while the microalgae were found to contain lutein, chlorophylls, as confirmed by HPLC analysis. The biocompatibility of the optimized extracts from selected strains was verified using the MTT assay on HaCaT cell lines. The aqueous extract from microalgae Chlorella vulgaris exhibited lower toxicity to HaCat cell line, with viability rates exceeding 85%. Yeast extracts from Rhodotorula toruloides initially showed higher viability rates, which, however, decreased with increasing extract concentrations.
Development of cereal products for specific nutrition with the addition of legumes, algae and yeasts
Pavlištíková, Nela ; Mikulíková, Renata (referee) ; Márová, Ivana (advisor)
This diploma thesis is focused on the development of cereal products for special nutrition with the addition of legumes, algae and yeast. In the theoretical part, expert knowledge about gluten-free cereals, their chemical composition, gluten and food fortification is developed. Then an overview of the legumes, algae and yeasts tested in this work was elaborated. As a part of the literature review, emphasis was placed on the chemical composition of the analysed products. In the experimental part, the characterization of selected gluten-free cereals and legumes was carried out. The tested cereals were buckwheat, quinoa and gluten-free oatmeal. Pea, red lentil and Beluga black lentil were selected from among legumes. Furthermore, various types of algae and yeast extracts were prepared, which were subsequently optimized. Algae of the genera Dulse, Chlorella and Spirulina were selected for enrichment of pseudocereals. Dried baker's yeast and Saccharomyces cerevisiae were chosen as yeast representatives. Phenolics, flavonoids, antioxidant activity, carbohydrates, proteins, fatty acids, lipids and lipophilic pigments were determined in gluten-free cereals and legumes. The content of -glucans and gluten were determined for in cereals as well. Some content of phenolic substances, flavonoids, antioxidants, total fatty acids, lipophilic substances, pigments and -glucans were found in extracts from algae and yeast. Selected samples were also subjected to antimicrobial and cytotoxicity tests. Finally, mixed cereal products were prepared from selected gluten-free cereals, legumes, selected algae and yeast extracts and algae biomass. Extracts were selected based on obtained results and subjected to MTT cytotoxicity tests. It was found that the addition of pea, extracts from algae and yeast or the algae biomass itself increased the protein content of the prepared mixtures. Furthermore, in hexane:ethanol extracts from Chlorella and Spirulina or their biomass, the amount of antioxidants has been increased. The obtained results show that the combination of cereals with addition of algae and yeast extracts is suitable for increasing the protein content in gluten-free products. It was also found that selected microalgae and yeast have the potential to enrich gluten-free products with bioactive substances, when using biomass or extracts produced from them.
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.
Study of genome of Metschnikowia yeasts by molecular methods
Schneiderwindová, Nicole ; Skoumalová, Petra (referee) ; Němcová, Andrea (advisor)
Yeasts of the genus Metschnikowia belonging to the family Metschnikowiacea are yeasts characterized by vegetative propagation through multilateral budding. These are yeasts widely distributed in nature. More than 35 species occurring have been defined in the wild. They most often occur on flowers, fruits, but also on insects or human skin. They have a wide range of uses due to their antifungal effects in agriculture and the cosmetics industry. This bachelor thesis deals with the study of usage of molecular methods to characterize selected species of yeasts of the genus Metschnikowia. It focuses on a detailed description of the yeast cell structure, karyotype and methods of reproduction in the theoretical part of the work. In the practical part on optimization and description of molecular methods including pulse gel electrophoresis methods used to separate the yeast genome and their subsequent observation of changes in individual parts of genome. First, the yeast was cultured under special conditions that are characteristic of Metschnikowia yeasts, then yeast DNA was isolated using methods suitable for DNA isolation, which was further examined by the PFGE molecular method. The DNA isolation procedure was first optimized for individual yeast strains, as it was necessary to verify the required ratio of low melting agarose to isolated DNA. That was because of it was important for the resulting gel blocks to be suitable for measurement by PFGE analysis. By optimizing the method was possible to create ideal blocks of isolated yeast DNA, which were subsequently subjected to PFGE analysis. Several measurements of PFGE analysis were performed at different time intervals in order to separate small and large yeast chromosomes. The CHEF standard of the yeast Hansenula wingei and the standard of the yeast Schizosaccharomyces pombe were used for the measurements. According to the measurement results, it can be determined that the yeast DNA isolation procedure and subsequent analysis by pulsed gel electrophoresis were successful, as the number of chromosomes of all used yeast species of the genus Metschnikowia was determined.
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.
Proteome and Metabolome Changes in Selected Organisms under Stress
Halienová, Andrea ; Kráčmar, Stanislav (referee) ; Čertík, Milan (referee) ; Šucman, Emanuel (referee) ; Márová, Ivana (advisor)
Living conditions of every organism are influenced by various factors at this time. Some of them have positive effect on organism, some negative. Basic condition for surviving is the ability to resist and adapt to changing metabolic and living conditions. Every single stress effect can lead to changes in metabolism but organisms have ability to develope sufficient mechanisms for stress response. Some of them are similar for all living organisms (enzyme production, endogenous primary stress metabolites) some of them are specific for certain organism or stress type. Cell stress response can be observed on different levels (proteomic, genomic, metabolomic). In proper conditions it can be used indrustrially. In this work, influences of various stress factors were studied. These factors were applied on selected organisms – carotenogenic yeast and plant materials. Yeast stress response was induced by osmotic and oxidation stress factors. Changes on proteomic level and in production of selected secondary metabolites were observed. Proteome was analyzed by 1D and 2D electrophoresis with subsequent analysis of proteins by mass spectrometry. Yeast strain Rhodotorula glutinis CCY 20-2-26 showed the best adaptation to stress factors, which was moreover accompanied by overproduction of carotenoids. This finding can be premise for next industrial production of carotenoids. In plant samples predominantly enzymes and metabolites involved in antioxidant response were studied.
Brewing industry
Artýszková, Jana ; Illková, Kateřina (referee) ; Omelková, Jiřina (advisor)
The aim of the theoretical part of the thesis is the study and the treatment of the problem of the manufacturing of beer, focused on the czech conditions and classical Czech technology. Within the theoretical part the history of this branch of industry together with the modern methods, enabling greater productivity of beer production, are summarized. Experimental part of the thesis was carried out in a small brewery in Czech republic, producing aproximately 10 000 hl per year. In this brewery the selected parameters were studied not only in the course of cooking and fermentation of beer, but during the output control in racking to the drums and plastic bottles, as well. The studied parameters were as follows: the sugar content of front and wort, the control of microbiological contamination in fermenting cellar and in beer-storage cellar, the content of CO2 by last stage of fermentation and pH- value and color by the end-product.
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.
Surface Treatment of Materials for BioTechnologies
Šupák, Marek ; Slámová, Jitka (referee) ; Krčma, František (advisor)
The theoretical part focuses on the importance of yeast, its role in brewing, the need for a reliable and economically beneficial pasteurization step that would meet modern requirements. Also in this part is defined plasma, its occurrence and the use of the glass structure used in the practical part. In the first part of the experimental work, the bachelor thesis deals with the action of plasma as a means of pasteurization. Saccharomyces cerevisiae yeast was introduced into the plasma. Gradually, the period of exposure of the yeast to the plasma discharge was determined and the number of survived and dead cells monitored. The methylene blue dye was used to identify yeast viability. After staining, the yeast was monitored under a microscope and calculated. Bürker's cell was used to determine the number of yeast cells. The experiment demonstrated plasma activity as a sterilization step, due to the decreasing number of living cells and the increase in the number of dead cells in the yeast-containing sample. In the 2nd part the surface was activated in the plasma discharge. The glass thus prepared was immersed in the culture medium for 24 hours to form a layer of culture medium on the surface of the glass. The remainders of the culture medium were then discharged and a small amount of yeast in the distilled water was pipetted. After 24 hours the yeast was counted on the Bürker's cell, the yeast growth was evaluated and the plasma activation efficiency was evaluated for activation and layer formation. The method of contact angles was used to confirm the effect of plasma on the surface of the glass. In this section, we demonstrated the effect of plasma on the surface of the glass and the formation of a thin layer of nutrient medium that supplied the yeast with the necessary substances for reproduction.
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.

National Repository of Grey Literature : 115 records found   1 - 10nextend  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.