National Repository of Grey Literature 234 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Synthesis and evaluation of potential antifungal agents
Straková, Jana ; Krátký, Martin (advisor) ; Novotná, Eva (referee)
Mycotic systemic infection is often very severe, whether due to patient immunodeficiency, the side effects of available antifungal agents, or clinical or drug resistance. Emphasis should therefore be placed on the timely determination of the correct diagnosis, appropriate indications of current drugs, and especially the development of new antifungal agents (ATM). The core of all synthesized compounds is the molecule of itaconic acid (IA) or its anhydride. The starting molecule was chosen based on its broad spectrum of biological activities, including antibacterial and antifungal activities. The aim was to create ten monoamides using a one-step synthesis of IA anhydride with the appropriate chlorinated aniline. These monoamides were then cyclized to form ten imides. The yields of the reactions to form the monoamides were high, with two exceptions (24% and 31%), and were generally above 80%. The yields of the reactions to form the imides were lower, ranging from 29% to 86%. The antimicrobial activity was tested using the broth microdilution method for all imides and most monoamides. All compounds were ineffective against gram-negative bacteria, and very low activity against gram-positive bacteria was shown by the compounds 1-(2,4,6-trichlorophenyl)-3-methylene-2,5-pyrrolidinedione,...
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.
Evaluation of selected bakery products based on different processing technology and recipe
HRDLIČKOVÁ, Vanda
Together with the emerging trends of healthy lifestyle, organic products and organic farming, the domestic production of various food products and the fermentation process are becoming increasingly more important for the population. Fermentation technologies cover a wide range of products in the food industry or in other fields. The first references mentioning fermentation of flour and water (i.e. sourdough) date back to 1500 BC in ancient Egypt, and despite new doughraising technologies such as baker's yeasts, baking powder and baking soda, it is sourdough starter that is becoming popular not only for bakers but also for the whole population. The aim of this thesis was to evaluate the effect of the sourdough starter used on the quality of bakery products. The first part is devoted to a theoretical overview concerning fermentations, cereals, bakery products and their production technologies. The second part of the thesis was practical, where samples of the produced bakery products were evaluated by two methods based on the baking experiment, i.e. sensory analysis and physicochemical analysis. The thesis was also complemented by a questionnaire survey. Significant differences were found in the physicochemical parameters of yeast-leavened and sourdough leavened loaves of bread (acidity, bulk density, ageing symptoms). A positive effect of leavening was also demonstrated in the sensory analysis, in which the sourdough loaves of bread were rated better by the evaluators than the leavened bread samples.
Preparation of Cosmetic Product Based on Microbial Extracts
Reichertová, Klára ; Trachtová, Štěpánka (referee) ; Hudečková, Helena (advisor)
This thesis is focused on the preparation of a cosmetic product based on microbial extracts. The thesis is divided into two main parts, theoretical and practical. The theoretical part describes the types of cultured microorganisms, microbial metabolites, legislation and safety of cosmetic products, composition of human skin and last but not least the applied analyses. The experimental part deals with the use of waste products of the food industry, specifically coffee grounds as a substrate for culture media. Furthermore, the cultivation is studied with a focus on the gain of metabolites useful in the cosmetic industry, the analysis of these metabolites by GC/FID and HPLC/PDA. The work addresses the preparation of microbial extracts, their testing including determination of polyphenol and flavonoid content and characterization of antioxidant activity and antimicrobial activity tested on bacterial cultures of Esterichia coli and Staphylococus epidermidis. The application of the analysed extracts and their application to the final product is also addressed. The last chapter discussed in this thesis to test the final product using Visioscope PC–35, instrument and performing sensory analysis. The cultured strains were Phaffia rhodozyma CCY 77-1-1, Cystophilobasidium macerans CCY 10-1-2, Rhodosporidium toruloides CCY 062-002-004 Chlorella vulgaris CCALA 924. The biomass obtained by cocultivation of Phaffia rhodozyma CCY 77-1-1 and Chlorella vulgaris CCALA 924 as well as the biomass of these two microorganisms cultured separately were used for the preparation of microbial extracts.
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.
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.
Yeasts and wine
Palíková, Petra ; Vadkertiová, Renata (referee) ; Vránová, Dana (advisor)
This thesis deals with isolation and identification wine yeasts from grapes and must. For analysis was used white wine Sauvignon that was grown and producing after needs ecological agriculture. Remove samples were processed in laboratory and by the help of dilution method were obtained pure culture isolated yeasts. In the following step, by the application of commercial kit UltraCleanTM Microbial DNA Isolation Kit we were able to isolated individual DNA that it was used to the next analysis. Isolated DNA was amplification by PCR method with ITS1 and ITS4 primers. PCR products were detected on agarose gel. Amplification samples were chopped five restriction endonucleases: HaeIII, HinfI, TaqaI, AluI and MseI. Chopped DNA was detected by the same way as PCR products and it was compared with restriction patterns of collection yeasts. In the next step it was compared genetic similarity of isolated yeasts by using BioNumerics software. As a criterion it was used Pearson coefficients and UPGMA clastering analysis. The result is dedrogram of genetics similarity isolated yeasts.
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.

National Repository of Grey Literature : 234 records found   1 - 10nextend  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.