National Repository of Grey Literature 130 records found  previous11 - 20nextend  jump to record: Search took 0.01 seconds. 
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.
Use of algae extracts in cosmetics
Plášková, Anna ; Rapta, Marek (referee) ; Márová, Ivana (advisor)
This thesis is focused on a preparation of extracts from selected species of algal and cyanobacterial strains, their characterization, a cytotoxicity testing and a use in cosmetic products. The theoretical part contains the review of a taxonomic classification and parameters of algae and cyanobacteria and basic information about used organisms. There is a description of the most significant factors influencing the algae cultivation and production of biomass. Further, active substances of algae and cyanobacteria, which could be used in cosmetic products as UV protective substances, were described. An overview of extraction techniques, encapsulation of active substance into liposomes and particles characterization, antioxidant activity analysis, and cytotoxicity tests is given too. In experimental part, antioxidant activity of algal extracts and chlorophyll a and carotenoid content were determined spectrophotometrically. The long-term stability of extracts was monitored for three weeks. Liposomes were prepared by sonification and encapsulation activity was analysed. The Dynamic Light Scattering method (DLS) was used for analysis of polydispersity and size of liposomes. Colloid stability of particles was determined by zeta potential. Cytotoxicity tests were performed using MTT assay. The prepared extracts, particles and lyophilized biomass of algal and cyanobacterial strain were further used as active substances in the formulation of cosmetic products (type o/w). These creams were tested on human skin.
Optimization of extraction of metabolites produced by selected strains of microalgae and carotenogenic yeast.
Obračaj, Jan ; Holub, Jiří (referee) ; Szotkowski, Martin (advisor)
This bachelor thesis is focused on the production of microbial biomass using selected strains of cyanobacteria and carotenogenic yeasts. Subsequent preparation of extracts and study of their stability under different temperature conditions with the addition of the antioxidant tocopherol. In the experiment, 2 series of extracts with hexane and ethanol were prepared. The theoretical part of the work describes the studied metabolites carotenoids, chlorophylls, ubiquinone, ergosterol and microbial lipids. Furthermore, the used strains of cyanobacteria and carotenogenic yeasts are described here. Finally, methods for extraction and analysis of metabolites are described. The experimental part describes the used cultivation techniques, preparation of microbial extracts and used analytical methods. The results part of the work then contains a summary of the results of long-term stability tests of extracts. The results of the work clearly confirm the temperature dependence of the stability of individual metabolites. This phenomenon was most evident in chlorophyll and carotenoid pigments. Hexane appears to be the best solvent in terms of the stability of the substances used. The results of this work provide important information in terms of the economics of storage of these valuable substances usable in the food, pharmaceutical or feed industries.
Application of chemical and physical stresses in the late phase of growth to selected strains of microorganisms
Langer, Marek ; Holub, Jiří (referee) ; Szotkowski, Martin (advisor)
A wide spectrum of microorganisms is used in the biotechnological industry for production of meaningful metabolites; including carotenoids and chlorofyles with antioxidant effects, fatty acids, ubiquinone and ergosterol. Ways to increase yield of metabolites to maximum capacity are being researched to increase efficiency and economical sustainability in industry. One of the ways is the application of chemical stress factors on microorganisms as is described in this thesis. In the theoritical part certain microorganisms, their important intracellular metabolites and their metabolism are established. The last subchapter covers the usage of stress factors in industry. In the experimental part each microorganism was subjected to various concentrations of sodium chloride, cobalt(II) sulfate and iron(III) chloride. Significant increase of lipid production was registered after an application of sodium chloride on yeast strain Rhodosporium toruloides. An increase in production of torularhodin in Sporidiobolus pararoseus occured after application of iron salt. After an application of sodium chloride the growth of torularhodin in strains Cystofilobasidium macerans a Rhodosporidium toruloides was significant. Sodium chloride was also a suitable stress factor for lycopene formation in Rhodotorula mucilaginosa. The most meaningful stress factor of algae was cobalt(II) sulfate which increased metabolite production in Scenedesmus obliquus. Cyanobacteria Anabaena torulosa also attained a significant production in the presence of sodium chloride.
Cavitation in engineering praktice
Kianička, Martin ; Hudec, Martin (referee) ; Pochylý, František (advisor)
This diploma thesis contains three parts. The first part is a background research which deals with notions such as cavitation and cyanobacteria. It also contains current phase in the use of cavitation. The second part deals with design, composition and constructional solution of hydraulic circuit on the riverboat. The third part deals with experimental certification of the cavitation effect on the cyanobacteria in the water. Design of the riverboat with the hydraulic circuit including the circuit itself and the cavitation tube was created in SolidWorks program, calculations, it’s processing and graphs were created in Microsoft Excel.
Spectrophotometric determination of phosphate in ternary systems with dyes
Novotný, Radek ; Komendová, Renata (referee) ; Sommer, Lumír (advisor)
The theoretical part of this master’s thesis is focused on the characteristics and forms of phosphorus, occurrence in natural waters and the problems associated with higher phosphorus concentrations, especially in the development of cyanobacteria and algae. There are also described the possibilities of determining the degree of pollution of natural waters by nutrients and the effects of eutrophication. There are also described methods for the determination of phosphates, especially spectrophotometric determination in ternary systems with dyes. Like other methods are mentioned AAS, ion chromatography, electrophoresis and izotachophoresis, electrochemical methods or enzymatic methods. In the experimental part of this work deals with the selection and optimalization of suitable ternary system with organic dyes for spectrophotometric determination of orthophosphates. The system with phosphovanadomolybdic acid is studied too. For analytical procedure with malachite green oxalate, which was found to be most useful, were studied interfering ions, commonly occurring in natural waters . The chosen procedure was finally tested on real water samples.
Numerical solution of the cavitation bubble dynamics
Münster, Filip ; Himr, Daniel (referee) ; Rudolf, Pavel (advisor)
This thesis deals with the numerical solution of cavitation bubble dynamics and with cyanobacteria gas vesicle behaviour. A program for the numerical calculation of bubble dynamics is created using the Rayleigh-Plesset equation and its modifications. Subsequently, bubbles of different sizes are investigated during acoustic cavitation with various driving frequencies. Furthermore, a model for hydrodynamic cavitation is created. The model combines CFD computation of flow in the Venturi nozzle with the cavitation bubble dynamics calculation. The last part of the work is dedicated to cyanobacteria gas vesicle behaviour in a variable pressure field and during passage through the Venturi nozzle.
Preparation of microbial, plant and algal extracts to use in cosmetics for infants
Janderová, Šárka ; Dzurická, Lucia (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with the preparation of a cosmetic product for infants with the addition of active substances from cyanobacteria, microalgae, or plants. In the theoretical part, a review was made, which not only summarizes the basic information about these organisms, but also the antioxidants contained in these microorganisms. In the practical part, several types of extracts from cyanobacteria, algae and plants were prepared and characterized. The content of phenolic substances, chlorophylls and content of carotenoids were measured spectrophotometrically. Content of soluble proteins was determined by Hartree-Lowry method and the fatty acid profile in biomass was obtained by GC. Furthermore, the SPF factor was measured using the spectrophotometric method the Mansur equation. Antioxidant activity was determined by using the TEAC method. Finally, two of the best extracts were selected for the preparation of cosmetic emulsions. The sensory analysis of prepared emulsions was performed for the period of two weeks.
A comparison of metabolic activity and use of microalgae and pigment-formed yeasts
Szotkowski, Martin ; Kočí, Radka (referee) ; Márová, Ivana (advisor)
Carotenoids are natural pigments occurring in plants and many microorganisms, such as algae, yeast and bacteria. They represent the most common group of antioxidants with significant biological effect. Lipids are an essential component of all living organisms. They are the source and the reservoir of energy for organisms, which can also be used in the petrochemical industry for the production of biofuels. This thesis deals with the production properties of carotenoids and lipids by selected strains of yeasts, algae, and canobacteria, in order to apply the acquired knowledge and find cheap suitable alternatives for microbial biotechnological production of these metabolites using waste substrates. Carotenoids, coenzyme Q, and ergosterol in cells were determined by liquid chromatography. The lipid content and fatty acid profile was analyzed by gas chromatography. Cell morphology and localization of selected metabolites were analyzed by fluorescence lifetime imaging microscopy. In this work yeast genera Sporobolomyces, Cystofilobasidium and Rhodotorula were used. As the representatives of the algae and cyanobacteria strains of Desmodesmus, Cyanothece, Chlamydomonas, Synechoccocus and Chlorella strains were studied. In the overall comparison, the yeast strains were more productive than algae and cyanobacteria. The highest carotenoid production was found in S. pararoseus, C. capitatum and R. mucilaginosa cells, while the highest lipid yield was observed in strains of C. infirmominiatum and S. metaroseus.
Cocultivation of yeasts and microalgae to produce enriched biomass
Bradáčová, Lenka ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
The diploma thesis is focused on the influence of biological stress formed by co-cultivation of heterotrophic (yeasts) and autotrophic (microalgae and cyanobacteria) organisms on the production of enriched biomass. The monitored groups of substances include carotenoids (-carotene, lutein, lycopene, astaxanthin, torularhodin), chlorophylls A and B, ergosterol and ubiquinone. Further, production of lipids was analyzed in the terms of fatty acid profile and lipid content in biomass. In the first part of the work, the yeast biomass production was investigated using different nitrogen sources. Glycerol was used as a carbon source in all parts of the work. Subsequently, the co-cultivation of yeasts with microalgae and cyanobacteria took place in a multicultivator with gradual increase of selected macroelements – nitrogen, magnesium and phosphorus. The last part of the work was focused on the co-cultivation of yeasts and microalgae in a laboratory fermenter. The best effect on the production of total biomass was the increased magnesium content and high nitrogen content in the basic medium. The best concentrations of carotenoids were achieved due to the double nitrogen and phosphorus content together. Chlorophyll production was significantly lower compared to carotenoids.

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