National Repository of Grey Literature 147 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Biological effects of complex extracts from yeast and algae biomass
Bočán, David ; Byrtusová, Dana (referee) ; Matoušková, Petra (advisor)
This bachelor thesis was focused on optimalization of extractions of active compounds from microalgae and carotenogenic yeasts. Other part of this work was focused on characterization of these extracts and their tests of cytotoxicity on human keratinocytes. In theoretical part a literary research which summarizes the basic properties and cultivation conditions of used microorganisms was conducted. Then there were listed an examples of antioxidant compounds found in these microorganisms as well as their properties. Finally the term cytotoxicity and methods of its measurement were clarified. The practical part of this thesis consists of series of extractions from mentioned microorganisms. These extracts were characterized by the content determination of phenolic and flavonoid compounds and also chlorophyll and carotenoid compounds. Determination of antioxidant capacity and SPF were done too. Lastly the cytotoxicity of chosen extracts was measured using the MTT test.
Study of production properties of Metschnikowia yeasts
Chadimová, Markéta ; Szotkowski, Martin (referee) ; Němcová, Andrea (advisor)
Metschnikowia yeasts are able to produce under different conditions different amounts of lipids, which have remarkable uses in biotechnology and industry. This bachelor thesis is focused on the study of cultivation conditions under which yeasts produce the most lipids and also deals with which fatty acids these triacylglycerols are composed of. The influence of cultivation conditions on the amount of biomass is also monitored. Five yeast strains were examined, namely M. pulcherrima 145, M. pulcherrima 147, M. pulcherrima 149, M. andauensis 129 and M. chrysoperlae 1158. Cultivation media with different C/N ratios, containing glucose or cheap waste substrates (glycerol, coffee and waste fat) were used for cultivation. The cultivations were performed at several temperatures and then the amount of grown biomass was determined, and the composition and ratio of fatty acids were determined by gas chromatography. As yeast that produced the most biomass per time was determined the yeast M. chrysoperlae 1158, which after 336 hours of growth at 15 °C was able to produce 10,66 g/l of biomass on a medium with a ratio of C/N = 100. The highest amount of lipids was obtained with yeast M. andauensis 129 at 8 °C on medium with a ratio of C/N = 100 (21,57 % lipids in dry matter). If biomass production is also taken into account, the best results are obtained by the yeast M. chrysoperlae 1158 at a temperature of 11 ° C on a medium with a ratio of C/N = 100 with a biomass production of 10,15 g/l and 19,58 % lipids in dry matter. This yeast was therefore further cultivated on waste substrates.
Byrtusová, Dana ; Kráčmar, Stanislav (referee) ; Kovalčík, Adriána (referee) ; Márová, Ivana (advisor)
Beta-glukany jsou polysacharidy složeny z monomerů D-glukózy. V dnešní době se -glukany těší zvýšené pozornosti zejména kvůli imunomodulační aktivitě a využitelnosti ve farmaceutickém a potravinařském průmyslu. Saccharomyces cerevisiae je dodnes jediným kvasinkovým zdrojem požívaným v biotechnologické produkci. Avšak některé kvasinky z oddělení Basidiomycetes, které jsou schopny produkce lipidů a karotenoidů, mohou být využity rovněž jako alternativní zdroj -glukanů. Dizertační práce se zabývá možností a optimalizací produkce -glukanů a dalších mikrobiálních sacharidů u karotenogenních kvasinek a mikrořas. Testovány byli zástupci rodů Rhodotorula, Sporobolomyces, Cystofilobasidium a Dioshegia. Z nekarotenogenních kvasinek byly do screeningu zařazeny kvasinky rodu Metschnikowia, askomycetní kvasinky a z mikrořas zástupci zelených a červených řas. Experimentální část cílí rovněž na možnosti koprodukce dalších metabolitů, jako jsou lipidy, pigmenty a extracelulární polymery. První část experimentu se zabývá vlivem čtyř C/N poměrů (10:1, 40:1, 70:1 a 100:1) na produkci biomasy, -glukanů, karotenoidů a lipidů. Ze všech testovaných kmenů, S. cerevisiae CCY 21-4-102, C. infirmominiatum CCY 17-18-4, P. rhodozyma CCY 77-1-1 a R. kratochvilovae CCY 20-2-26 vykazovaly nejvyšší produkci -glukanů a byly proto vybrány k podrobnější optimalizaci, zejména osmotického stresu, teploty a zdroje dusíku v kultivačním médiu. Dodatečně, kmen R. kratochvilovae CCY 20-2-26 je schopný produkce extracelulárních glykolipidů a S. pararoseus CCY 19-9-6 extracelulárních polysacharidů. Následně bylo stanoveno množství -glukanů u dalších dvanácti kmenů S. cerevisiae a rovněž možnost produkce polysacharidů u mikrořas.
Study of genome of Metschnikowia yeasts by molecular methods
Schneiderwindová, Nicole ; Matoušková, 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.
Antimikrobiální vlastnosti rostlinných látek
Žižlavská, Barbora
This diploma thesis deals with the antimicrobial properties of herbal substances. Characteristics of these substances, including mechanism of action on microorganisms and their industrial use, is presented in the theoretical part. The aim of microbiological analysis was to determine the extent of diluted (10%) and concentrated essential oils isolated from clove (Syzygium aromaticum), cinnamon (Cinnamomum), and thyme (Thymus vulgaris) against bacteria (Escherichia coli, Enterococcus faecalis, Enterococcus faecium) and yeast (Yarrowia lipolytica, Candida tropicalis and Saccharomyces cerevisiae). To determine them, the disc diffusion method was used. The results confirmed an antimicrobial effect of tested essential oils. Concentrated thyme essential oil had the hightest inhibitory activity on all used microbial strains.
Mikrobiální kontaminace medů
Sojková, Tereza
The diploma thesis Microbial contamination of honeys in the literature recherche presenting chemical composition of honey, its properties and effects to human health. The major part deal with microbial contamination of honey, characterization of important groups of microorganisms and describing defects of honey produced their activities. Further it shows with possible ways of precaution against these undesirable changes. The experimental part is focused on microbiological analysis and spectrophotometric measurement of floral and honeydew color, purchased directly from beekeepers from the region Vysočina. Investigating changes in numbers of microorganisms and changes color over time.
Technologické možnosti výroby ciderů a sladinových kvašených nápojů
Sojka, Jakub
This thesis is mainly devoted to the production of cider, which has been booming in the Czech Republic in recent years. Emphasis is put on the selection of suitable varieties of apples as well as on the whole technological process of production, from fermentation and ripening to product bottling. The production process is enriched with knowledge from wine-making practices, which could be a useful aid to achieve first-class quality and product diversity, especially regarding the knowledge of maceration and maturing using wood. Part of the thesis is also devoted to malt fermented beverages. It describes the process of making malt and fermentation using brewing yeast. Subsequent treatment options after fermentation and ripening are the same as for ciders and this after-fermentation treatments are associated and valid for both types of beverages. The practical part is devoted to the production of samples of cider and malt fermented beverages. The impact of both apple varieties and brewing/wine yeasts on the sensory quality of ciders is investigated. The last part is devoted to the possibilities of flavoring malt fermented beverages. Sensory analysis was performed on all samples and HPLC analysis was performed on selected samples.
Možnosti technologických postupů při výrobě vína a jejich optimalizace
Kostihová, Lucie
The bachelor thesis is focused on technological processes for wine production. It is dedicated to modern methods of wine making process from grapes and also to tradi-tional production mainly applied by small winemakers. The first chapter describes the history of the cultivation and production of wine in the world and in our country from ancient times to the present. The second chapter investigates the individual stages of wine production. It describes the composition of grape and grape harvesting, their proc-essing from stamping, through adjustment of must, spontaneous alcoholic fermentation or fermentation with the aid of pure cultures of wine yeasts. In the thesis is mentioned malolactic fermentation which is increasingly used in the wine production. It is realized with the help of lactic acid bacteria such as Oenococccus oeni. Also the thesis intro-duces with stabilisation of wine and its bottling. The third part deals with the yeasts used in the wine industry. It is focused on various strains of wild yeasts but also pure yeast cultures used in modern wine production.
Mikrobiální kontaminace baleného masa
Cholastová, Kateřina
A description of packaged meat microflora is provided in this bachelor thesis. It deals with the chemical composition of meat and the factors influencing the growth of microorganisms. Main topic is the characterization of microorganisms causing spoilage of packaged meat and microorganisms causing formation of foodborne illnesses. Methods of fighting against undesirable microorganisms are also included. The thesis contains packaging types characterization, options in the packing of meat, packaging requirements, and shortcomings during the packing. The experimental part is focused on determining the most important microorganisms' groups appearing in samples of differently packaged meat.
Precizace technologie Hřebečské medoviny
Bakrlíková, Veronika
The diploma thesis deals with the production of mead and problems of flavoring and adding alcohol to mead in contradiction with the required quality and demand for the purity of the product. History, individual steps of mead production such as fermentation, cleaning and finishing, including basic raw materials, are described here. The conclusion of the theoretical part briefly describes the defects of mead and methods of servis mead. The practical part deals with the main fermentation of the honey liquid with respect to the concentration of honey, the temperature during fermentation and the different types of yeast. By measuring with the OenoFoss device and the refractometer, I monitor the daily loss of sugar during the main fermentation and compare it with other samples. Further, using microbial isolation, I monitor yeast development after fermentation and final ethanol production. Part of the thesis is also identification of yeast by PCR and subsequent electrophoresis.

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