National Repository of Grey Literature 72 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Controlled production of lipids and lipidic substances by selected yeasts and microalgae
Szotkowski, Martin ; Kráčmar, Stanislav (referee) ; Huelva, Ines Garbayo Nores, University (referee) ; Márová, Ivana (advisor)
Karotenoidy jsou přírodní pigmenty vyskytující se v mikroorganismech jako jsou řasy, kvasinky a sinice. Představují nejrozšířenější skupinu antioxidantů s významným biologickým účinkem. V současnosti vzrůstá zájem o karotenoidy vzhledem k jejich příznivým vlivům na lidské zdraví. Chlorofyly jsou zelená fotosyntetická barviva, která nacházejí uplatnění v potravinářství jako intenzivní zelená barviva. Koenzym Q je znám svým pozitivním vlivem pro správnou funkci řady orgánů v lidském těle. Ergosterol je nedílnou součástí membrán kvasinek a hub. Je to provitamin D2, který je důležitou součástí imunitního systému. Mikrobiální lipidy, nebo také ‚‚Single cell oils‘‘ jsou charakteristické vysokým obsahem zdraví prospěšných nenasycených mastných kyselin, které lze využít ve farmacii či kosmetice. Mikrobiální lipidy jsou dále studovány jako alternativa pro výrobu biopaliv. Dizertační práce byla zaměřena na studium a možnosti optimalizace produkce lipidů a lipidických látek vybranými kmeny karotenogenních kvasinek, mikrořas a sinic. V rámci práce byly testované kvasinky rodu Rhodotorula, Rhodosporidium, Cystofilobasidium a Sporidiobolus podrobené kultivacím na sérií médií s různými C/N poměry v rozsahu 13 až 100, obsahujících upravené odpadní substráty z potravinářského průmyslu. Vybrané kmeny byly poté kultivovány v bioreaktorech v médiu obsahujícím kombinaci odpadních substrátů. Kultivace mikrořas rodu Desmodesmus, Scenedesmus, Chlorella, Coccomyxa, Chlamydomonas, Botryococcus se zabývaly optimalizací jednotlivých komponent média a aplikací různých stresů s cílem navýšení produkce studovaných metabolitů. V rámci experimentů s extrémofilní mikrořasou Coccomyxa byly provedeny pilotní velkoobjemové kultivace v otevřených nádržích. V závěrečné části byl provedeny pilotní screeningové a velkoobjemové bioreaktorové experimenty zaměřené na možnosti kokultivace karotenogenních kvasinek a mikrořas. Testované kmeny kvasinek byly s rozdílnou úspěšností schopny utilizovat média obsahující hydrolyzované odpadní substráty. Nejlepším kmenem byl Sporidiobolus pararoseus, který na médiích dosahoval nejvyšších produkcí biomasy i sledovaných metabolitů. Z testovaných odpadních substrátů byla nejlepší kombinace odpadního fritovacího oleje a hydrolyzátu kávové sedliny. Úspěšná optimalizace složení hlavních komponent minerálního média vedla k zvýšené produkci studovaných metabolitů. Největší vliv měl optimální poměr P/N a aplikace oxidačního stresu. Nejlepších výsledků dosáhly mikrořasy rodu Desmodesmus a Scenedesmus. Velkoobjemové kultivace Coccomyxy onubensis potvrdily rezistenci kultury proti kontaminaci vnějšími vlivy a schopnost růstu za vysoké teploty a intenzity světelného záření. Kokultivační experimenty potvrdily schopnost symbiotického růstu kvasinek a mikrořas. Nejlepších výsledků dosahovaly všechny testované kvasinky s mikrořasami rodu Demsodesmus a Scenedesmus a v menší míře i rodu Coccomyxa.
Synthesis and studies of novel difuranone heterocycles for optoelectronic applications
Szotkowski, Martin ; Ing. Jan Vyňuchal, Ph.D (referee) ; Krajčovič, Jozef (advisor)
Organic electronics is a progressive field of science that combines knowledge of many disciplines concerned with the study and application possibilities of organic molecules from both, the low-molecular segment as well as the oligomers and polymers. Such molecules are well recognizable by their excellent properties and variability of their structure. This thesis deals with properties, applications and brief research review of benzodifuranones and diketopyrrolopyrroles as the representatives of smart molecules. Furthermore various synthetic approaches to the preparation of both symmetrical and unsymmetrical benzodifuranones are described. Experimental part is focused on the development of hydroxy(thiophene-2-yl) acetic acid initial intermediate for the development of benzodifuranone analogues containing aromatic thiophene core.
Metabolic adaptation of selected microalgal strains on various nitrogen sources
Kodajek, Matěj ; Šimanský, Samuel (referee) ; Szotkowski, Martin (advisor)
Microalgae and cyanobacteria are photosynthetic organisms that, together with other microorganisms (yeast, bacteria), are used in industry, because they produce a wide range of interesting organic substances. This thesis deals with the metabolic adaptation of microalgae Scenedesmus obliquus, Scenedesmus acutus, Scenedesmus dimorphus, Chlamydomonas reinhardtii, Coccomyxa sp. and cyanobacteria Synechococcus nidulans, Arthrospira maxima, Limnospira maxima, Anabaena torulosa, which were cultivated on various nitrogen sources. These strains are descibed in the theoretical part including the metabolites and their applications in industry. The experimental part describes all chemicals, aids, devices and methods used for cutivation and analysis of microorganisms. The aim of the study was to compare and find out which nitrogen source in the BBM and SPIRULINA medium is the most suitable for a particular strain in terms of production of total biomass and composition of individual metabolites. Sodium nitrate, ammonium sulfate, glycine, urea and whey protein were used as nitrogen sources. The content and composition of lipids in the biomass was determined by gas chromatography. The content of ubiquinone, carotenoids and chlorophylls was determined by liquid chromatography.
Metabolic adaptation of carotenogenic yeasts to nutritional stress induced by selected wastes of the food industry
Plhalová, Žaneta ; Šimanský, Samuel (referee) ; Szotkowski, Martin (advisor)
This bachelor thesis deals with the production of carotenoids and lipids by selected strains of carotenogenic yeasts cultivated on waste substrates of the food industry. The production properties of the yeast strains Sporidiobolus pararoseus, Sporidiobolus metaroseus, Cystofilobasidium macerans, Rhodotorula mucilaginosa, Rhodotorula kratochvilovae and Rhodosporidium toruloides were studied. The cultures were cultivated by using waste products of food industry: waste frying oil, coffee oil which was obtained by extraction from coffee grounds and waste animal fat from rendering plants. The work consists of two main parts. The theoretical part describes the individual genera of yeasts, monitored metabolites, waste products and methods of analysis of monitored metabolites. The experimental part is focused on the processing of used waste substrates, cultivation of yeasts, acquisition and processing of biomass and analysis of metabolites. Rhodosporidium toruloides and Sporidiobolus pararoseus strains were the most suitable for the production of carotenoids on waste substrates. The highest production of lipid substances was measured in the strain Sporidiobolus pararoseus.
Application of physical and chemical stress factors in different stages of growth to autotrophic microorganisms
Sniegoňová, Pavlína ; Byrtusová, Dana (referee) ; Szotkowski, Martin (advisor)
Nowadays, the demand for metabolites produced by microalgae and cyanobacteria is still growing, due to their positive effects on the human body and health. These metabolites include mainly carotenoid pigments, that have antioxidant properties, which very attractive to consumers. These substances are mainly used in food supplements; however they are also used in the pharmaceutical industry. These substances include, for example, -carotene, but also chlorophylls, which are significantly involved in the photosynthesis process. Other important metabolites are lipids, which are part of cellular structures and serve a number of other functions. The theoretical part focuses on the description of algae and cyanobacteria and their cultivation. Furthermore, the influence of stress factors on the production of biomass and metabolites. Metabolites are then characterized in terms of properties and biochemical pathways leading to their production. Subsequently, there are mentioned evaluation techniques used to characterize the cultivated biomass. In the result part, the production properties are compared depending on the selected stress factors.
Microbial production of lipid substances using waste substrates
Árendásová, Veronika ; Szotkowski, Martin (referee) ; Němcová, Andrea (advisor)
This bachelor’s thesis examines the issue of lipid production, done through selected Metschnikowia strains gained from waste starch substrates. Produced lipids are extensively used in biotechnological processes. Cultivation utilised waste starch substrates, left over from food production, as they constituted an available and economical material. The study also monitored the growth of individual Metschnikowia strains in laboratory and reduced temperatures, using an optimal medium. The yeast’s production properties were analysed by means of gas chromatography. All selected Metschnikowia strains were able to produce lipid from waste substrates. Lipid production increased when a mixture of glucose and waste substrates was used. The amount of lipids and the share of fatty acids strongly depended on the strain and cultivation conditions. In all examined strains, monounsaturated fatty acids were represented most strongly. The Metschnikowia pulcherima 149 adapted best to waste substrates.
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.
Simultaneous co-cultivation of selected strains of carotenogenic yeasts and autotrophic bacteria
Blažková, Jana ; Němcová, Andrea (referee) ; Szotkowski, Martin (advisor)
The submitted diploma thesis was focused on the study of co-cultivation of selected microorganisms, which were carotenogenic yeasts and cyanobacteria. The production of selected metabolites was compared in these co-cultivations. The main metabolites monitored were carotenoids, sterols, coenzyme Q10, chlorophylls and lipids. Furthermore, this work focused on the study and possibilities of optimizing the production of lipids and lipid substances in selected strains of carotenogenic yeasts and cyanobacterial species. The theoretical part is focused on the description of yeasts, especially carotenogenic yeasts, cyanobacteria and the chemical composition of the produced metabolites. Microorganisms such as yeast and cyanobacteria contain carotenoids, which are natural pigments and are classified as antioxidants. As antioxidants, they have significant biological effects, such as effects on human health. Coenzyme Q has a positive effect on the functioning of organs in the human body. Chlorophyll is widely used in the food industry as a green dye. Lipids produced by microorganisms contain a large amount of unsaturated fatty acids, which is currently used in cosmetics or pharmacy. The theoretical part also described the individual analytical methods by which the production of the monitored metabolites could be determined. The experimental part is focused on the production of carotenoids, sterols, coenzyme Q10 and chlorophyll, which were determined by HPLC, lipids and fatty acid profile were determined by GC. The determined metabolites are monitored in different types of co-culture partners (carotenogenic yeast and cyanobacteria) in media with different additions of macroelements (P, N and Mg). This was followed by a co-cultivation experiment using waste oils (frying and coffee oil) and a study of the effect of waste oils added to co-cultivations. Co-cultivation experiments confirmed the ability of carotenogenic yeasts and cyanobacteria to grow together. The best results were obtained with Rhodosporidium toruloides and Anabena torulosa, Rhodosporidium toruloides and Arthrospira maxima.
Addition of probiotics and algae extracts to baby foods
Liová, Alexandra ; Szotkowski, Martin (referee) ; Němcová, Andrea (advisor)
This bachelor thesis deals with the selection of a suitable combination of probiotic culture with algae extracts as an addition to the baby formula and the application of the optimal composition of baby formula. Arame, wakame, hijiki and kombu seaweeds were selected for these purposes. The theoretical part is focused on the proper nutrition of children, their deficiencies and possible diseases. Subsequently, it deals with the characterization of probiotic cultures and their importance in the child's nutrition. Last but not least, the theoretical part characterizes the individual seaweeds, their nutritional composition and also their importance in the child's nutrition. In the experimental part, samples of selected algae were first analyzed in terms of saccharides, insoluble fiber content, fructooligosaccharides and -glucans or pigment content. A sample of inulin, a commonly used prebiotic in probiotic products, was used as a reference component. An important analysis of this experimental part was to determine the effect of algal extracts on the viability and growth of probiotic bacteria. Subsequently, a model digestion of a mixture of probiotics and algal extracts was performed, and the condition of the probiotic cells was evaluated during digestion and after digestion by measuring turbidity and flow cytometry. Finally, not only the optimal combination of algae extract and probiotic culture was proposed, but also the possibility of improving the long-term viability of probiotic cells in combination with algal extracts.
Use of some microbial oils in foods and cosmetics
Požgayová, Viktória ; Szotkowski, Martin (referee) ; Márová, Ivana (advisor)
This bachelor thesis focuses on preparation of microbial oils from oleaginous yeasts and the subsequent characterization of their properties and biological effects on organisms. The thesis is divided into two main parts, theoretical and experimental part. The theoretical part provides an overview of information about microbial oils and the possibilities of their current or future applications in food and cosmetic industry. It also describes other lipophilic metabolites synthesized by carotenogenic yeasts and briefly characterizes the carotenogenic yeast strains as well as analytical methods used in the experimental part. Experimental part was focused on the process of optimization of the extraction of lipophilic active compounds from yeast biomass. The best option proved to be the combination of three solvents such as dimethyl sulfoxide, hexane, and ethanol. Using this approach, the extracts were prepared from Rhodotorula kratochvilovae, Rhodotorula mucilaginosa, Rhodosporidium toruloides, Cystofilobasidium macerans and Sporobolomyces pararoseus biomass. All of the prepared extracts were characterised based on the content of lipophilic metabolites by UV-VIS spectrophotometry and by analysis on HPLC/PDA and GC/FID. Furthermore, the antioxidant activity, SPF, antimicrobial effect, and short-term stability of these extracts were determined. The best temperature to preserve these extracts proved to be 7 °C. Three extracts with the highest SPF values were chosen and added to the prepared cosmetic emulsion which was characterized and the sensory analysis was carried out. The MTT cytotoxicity assay on human HaCaT keratinocytes was realized for the three extracts that were added to the prepared cosmetic product as well as for their combination.

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1 Szotkowski, Marek
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