National Repository of Grey Literature 95 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Glycerolipids and carotenoids in microalgae: the implications in ecophysiology and applied phycology
Střížek, Antonín ; Nedbalová, Linda (advisor) ; Brányiková, Irena (referee) ; Barreira, Luísa (referee)
Lipids are basic biomolecules found in all organisms. They have a key function as structural molecules forming cell membranes, and, in the form of fats and oils, energy is also stored. There are a huge number of lipid types that have other functions, for example, in cell signaling, enzyme support, protection against stress, and others. Microscopic algae are the main primary producers in both freshwater and marine ecosystems. Therefore, algal biosynthesis has a fundamental effect on the trophic networks of aquatic ecosystems and ultimately on humans. The environment affects the ecophysiology of algae, which is reflected in their biochemical composition, i.e. in the composition of their lipids. This work is focused on two groups of lipids, namely glycerolipids, which consist of fatty acids, and carotenoids, which are photosynthetic pigments with antioxidant and photoprotective properties. In these groups of lipids, the target substances were further selected, namely polyunsaturated fatty acids and the carotenoid fucoxanthin belonging to xanthophylls. These substances are important not only in the ecophysiology of algae, but they are valuable substances that have positive effects on the human organism and, with the help of optimized cultivation, could be obtained from algae for industrial production...
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.
Recovery of waste from processing of phosphorus to produce materials with increased added value
Hejsek, Michal ; Zavřel, Tomáš (referee) ; Ing.Jan Červený, Ph.D. (advisor)
This master thesis focuses on reuse of waste water from industrial plant processing yellow phosphorus. Theoretical part summarizes physical and chemical properties of phosphorus, its transport in biosphere and its role in living organisms. Also the production process of the industrial plant is described. Waste water that contains waste byproducts is considered to be useful source of essential nutrients for economical large scale microalgae cultivation and development of biotechnological processes. In practical part, optimization of growth conditions for microalgae Chlorella pyrenoidosa Chick (IPPAS C-2) cultivation in medium based on wastewater from yellow phosphorus warehouse is presented.
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.
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.
Production of selected metabolites by yeasts and algae cultivated under stress conditions
Mariničová, Veronika ; Kočí, Radka (referee) ; Márová, Ivana (advisor)
The presented work was focused on the comparison between the production of selected metabolites by carotenogenic yeasts and microalgae cultivated under conditions of external stress. The main metabolites of interest were carotenoids, further lipophilic substances and lipids. Biotechnological overproduction of these metabolites could serve as a source of potentially beneficial substances not only for the pharmaceutical, cosmetic and food industries, but also for the production of third generation biofuels. Recently, there has been a growing interest in biofuels primarily from microalgae, which have a high potential in biofuel production and seem to be a promising source. The theoretical part deals with the description of individual genera of carotenogenic yeasts, microalgae, cyanobacteria, chemical composition of produced metabolites and brief biosynthesis. In addition, individual methods for analyzing the production of the metabolites of interest were described. The experimental part is focused on the comparison of production of carotenoids, coenzyme Q, ergosterols (phytosterols) and lipids by yeasts, microalgae and cyanobacteria. As a source of external stress, temperature, salt and light stress were chosen. The strains of Rhodotorula glutinis, Rhodotorula mucilaginosa, Sporidiobolus pararoseus and Cystofilobasidium macerans were studied from the yeast strains. Microalgae and cyanobacteria were Scenedesmus obliqus, Scenedesmus dimorphus, Chlorella sorokiniana, Chlorella saccharophila, Botryococcus brauni, Synechococcus nidulans and Arthrospira maxima. The yeast and algal strains were optimized for growth, carotenoid and lipid production. Applied salt stress showed a significant liquidation effect on algal and cyanobacterial strains. The thesis also monitored the biological stress, so-called co-cultivation of microalgae and yeasts. Further experiments will be the subject of future work.
Characterization of yeast and algae metabolites by instrumental techniques
Kurowska, Klára ; Márová, Ivana (referee) ; Němcová, Andrea (advisor)
The presented diploma thesis deals with the analysis and production of selected microbial metabolites of the yeast Rhodotorula kratochvilovae in comparison to various species of microalgae. The theoretical part summarizes the knowledge about the conditions for optimal growth and production of secondary metabolites. Analytical methods, by which metabolites were quantified and evaluated, were also described. In the experimental part of this thesis, the amount of accumulated biomass, exoglycolipids, intracellular lipids, phycobiliproteins and carotenoids according to various nutrient sources in the culture medium was studied. Specifically, the yields of these metabolites were investigated in the utilization of various sources of nitrogen (yeast extract, urea, ammonium sulfate, ammonium chloride and potassium nitrate), carbon (glucose, mannose, xylose, glycerol and lactose) and at variable C / N ratios (20; 40; 70; 100 and 120: 1) ideally selected sources of observed nutrients in partial experiments. The last part of the experiment was focused on comparison of the analysis of metabolites of autotrophic algae (chlorophylls, phycobiliproteins and lipids).
Cultivation of microalgae and carotenogenic yeasts under stress conditions
Sniegoňová, Pavlína ; Skoumalová, Petra (referee) ; Szotkowski, Martin (advisor)
In biotechnological industry we can register greater use of microorganisms like microalgae and carotenogenic yeast for production of selected substances or for valorisation of waste materials. Among metabolites produced by these microorganisms are carotenoids, which are natural pigments with antioxidant and other biological effects. Other significant produced substances are lipids, which represent large range of substances in living organisms. They form cellular membranes and serve as a reservoir of energy. These substances can be used in food, cosmetic and pharmaceutical industry and also in production of biofuels. Theoretical part is focused on description of selected genera of microorganisms, their cultivation and produced metabolites. Stress factors to which they were exposed are also mentioned, as are the analytical methods used for detection of produced metabolites. Next part is dedicated to the comparison of production properties of selected microorganisms depending on used stress factor. Increased production of lipids in yeast is observed in C. macerans and S. metroseus with higher concentrations of FeCl3. While using whey as a source of ccarbon, yeasts show decreased production of carotenoids. Highest production of lipids in algae and cyanobacteria was observed in S. acutus and D. quadricaudea. Production of carotenoids depended on applien stress factor and highest productions was observed in C. sorokiniana, C. reinhardtii, D quadricaudea and Coccomyxa sp.
Optical Micromanipulation Techniques Combined with Microspectroscopic Methods
Pilát, Zdeněk ; Prášil,, Ondřej (referee) ; Mojzeš, Peter (referee) ; Zemánek, Pavel (advisor)
Předložená dizertační práce se zabývá kombinací optických mikromanipulací s mikrospektroskopickými metodami. Využili jsme laserovou pinzetu pro transport a třídění živých mikroorganismů, například jednobuněčných řas, či kvasinek. Ramanovskou spektroskopií jsme analyzovali chemické složení jednotlivých buněk a tyto informace jsme využili k automatické selekci buněk s vybranými vlastnostmi. Zkombinovali jsme pulsní amplitudově modulovanou fluorescenční mikrospektroskopii, optické mikromanipulace a jiné techniky ke zmapování stresové odpovědi opticky zachycených buněk při různých časech působení, vlnových délkách a intenzitách chytacího laseru. Vyrobili jsme různé typy mikrofluidních čipů a zkonstruovali jsme Ramanovu pinzetu pro třídění mikro-objektů, především živých buněk, v mikrofluidním prostředí.
Control of algal bioreactors
Rek, David ; Naď, Martin (referee) ; Máša, Vítězslav (advisor)
The bachelor’s thesis discusses the matter of cultivation of microalgae in an artificially altered environment – bioreactor. The aim of the thesis is to determine and present the factors influencing the growth of microalgae and to find means of automated regulation of such factors. Nowadays, the majority of bioreactors are laboratory ones and are mostly being operated manually. The recent increase in demand for this technology results in many pilot-plant tests with a wide variety of microalgae. Tests such as these will be required to be automated to serve properly in future research. The thesis is based on professional literature and articles. The first part is to familiarize the reader with the wide number of potential applications of microalgae technology in various fields, such as the food industry, water treatment or separation of CO2 from ambient air or waste gas. The next segment presents the factors influencing the growth of microalgae and lastly the system of required equipment and sensors for automated operation is described. The bachelor’s thesis summarizes the important information necessary for the construction and unattended operation of microalgae bioreactor with respect to maximalization of productivity.

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