National Repository of Grey Literature 77 records found  beginprevious43 - 52nextend  jump to record: Search took 0.03 seconds. 
USE OF COMPLEX EXTRACTS FROM PLANT AND MICROORGANISMS IN FOODS AND COSMETICS
Uhlířová, Renata ; Kovalčík, Adriána (referee) ; Vorlová, Lenka (referee) ; Márová, Ivana (advisor)
The presented doctoral thesis is focused on optimalization of preparation of extracts of various origin (plant and microbial). The influence of extraction agent, disintegration of microbial cells as well as special techniques for enhancement of extraction process effectiveness (ultrasound and microwaves) were monitored. As part of the characterization, considering the source material, the composition of the prepared extracts was analyzed both spectrophotometrically and using liquid and gas chromatography. The most suitable extraction procedure varies depending on the type of material. For herbal samples, the highest content of active substances was achieved when the extraction facilitated by microwaves was used. Contrarily, the optimal method for cyanobacteria is the traditional extraction method, which is carried out for 24 hours at laboratory temperature. The most suitable method for extracting the active substances from yeast was a combination of DMSO, ethanol and hexane. Further, the effect of extracts on microbial cultures of bacteria (E. coli, S. epidermidis, C. acnes) and yeast (C. glabrata) was observed. For cytotoxicity evaluation MTT and LDH assays were performed on HaCaT and Caco2 human cell lines. The antimicrobial tests have demonstrated the antimicrobial, antibacterial and antifungal effect of a numerous extracts, especially the essential oils of Lavandula angustifolia and Mentha piperita. On the other hand, the cytotoxicity tests showed that the most of the extracts were safe for the use in the food industry and cosmetics within a range of up to 10% by volume. To improve stability, the prepared extracts were enclosed into liposomal particles enriched with PHB polymer (0–100%). Using a ZeteSizer NanoZS device, the particles' size, polydispersity index, and colloidal stability were assessed. The cryoTEM was used to examine the particle´s morphology. Liposomes and liposomes with the addition of 20 % PHB (PHB20) were evaluated as the most suitable particles for encapsulation of the prepared extracts. Excellent stability and high encapsulation efficiency were displayed by the produced particles. Genotoxicity testing with SOS chromotest on the model organism E. coli did not reveal any genotoxic effects. As an alternative method to achieve stabilization of active substances, nanofibers from PHB were prepared by three different techniques and gelatin nanofibers by electrospinning. The fibers were monitored for their diameter, uniformity, distribution on the collector using SEM and the gradual release of active substances from the fiber structure. The evaluations revealed that the forcespinning and electrospinning techniques were the most appropriate for further investigation. A continuous release of active ingredients was achieved by incorporating extracts into nanofibers. Several applications of prepared materials in the food industry and cosmetics were designed and developed as part of this work. The base emulsion's stability and general qualities were improved when green coffee and carotenogenic yeast extracts were added. The usage of emulsions containing coffee and yeast extracts would be suitable as sunscreens, and after the addition of Spirulina extract, as day or night anti-wrinkle creams. Energy drinks of the new type based on coffee with the addition of encapsulated plant extracts enable gradual release of caffeine and antioxidants during digestion.
Characterization of biological effects of extracts obtained from yeasts and autotrophic microorganisms
Špačková, Dominika ; Bendová, Agáta (referee) ; Szotkowski, Martin (advisor)
Carotenogenic yeasts and microscopic autotrophic microorganisms are increasingly being studied in the biotechnology industry because of their ability to produce a variety of substances with a wide range of utilization. These substances mainly include lipids and carotenoids, which are used in the food and pharmaceutical industries. The aim of this bachelor thesis is to determine the way these microorganisms behave in the presence of stress factors, and which of them would have a positive effect on the production of metabolites that can be further used in various industries. The theoretical part is dedicated to a characterization of substances produced by carotenogenic yeasts, cyanobacteria and microalgae, which will be further analyzed in the experimental part. The metabolites mainly include carotenoids, which are a wide group of naturally occurring pigments that possess, among other things, antioxidant and provitamin activity. No less important substances produced by these organisms are lipids, which are part of cell membranes, they also serve as a reservoir of energy, and the substances contained in lipids are part of the precursors of many hormones. Yeast cell walls also contain -glucans, which have many beneficial effects on immunity and human health. Due to this fact, interest in their research have been rising recently. The analytical methods used to determine these substances are also mentioned, as well as stress factors and their effects on the cells of the mentioned organisms. The experimental part deals with the exposure of these microorganisms to oxidative stress and stress caused by heavy metals. The aim was to analyze which concentrations of these stress factors are lethal to microorganisms, and which of them are optimal for increase of the production of the above-mentioned substances. Of the yeast strains, the strains Sporidiobolus pararoseus and Rhodotorula mucilaginosa achieved increased production of metabolites due to selenate ions. In contrast, cobalt had a beneficial effect only on the accumulation of lipids and -glucans in cells. The positive effect of selenium was also observed in the strain Chlorella minutissima and Arthrospira maxima, however, the most remarkable changes in the production of metabolites were achieved by the addition of the optimal concentration of the solution inducing oxidative stress.
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.
Methods and technologies for carbon dioxide capture in industrial plants
Rek, David ; Máša, Vítězslav (referee) ; Sukačová, Kateřina (advisor)
The rising level of carbon dioxide in the atmosphere has negative effects on life on our planet. Humanity is now dealing with the issue through multinational organizations which attempt to motivate the current industry to develop innovative solutions to increase the energy-efficiency while lowering the amount of produced emissions. The most affected are energy-intensive sectors of the industry, such as the ceramics industry. This diploma thesis is based on a thorough research conducted on scientific literature, mainly scientific articles. The theoretical part is to familiarize one with the issue of rising levels of carbon dioxide. Next, methods to capture, store and use the gas are presented. Furthermore, the thesis focuses on one such method – microalgal bioreactors. The practical past weighs the usability of microalgal bioreactors for the purpose of carbon dioxide emissions capture in a production company LASSELSBERGER, s.r.o. belonging to the ceramic industry. Tubular bioreactor with a volume of 2000 m3 would process 3,75 % of CO2 produced by the core production machine – spray drier, during this process 367,92 tons of microalgal biomass would be produced annually.
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.
Cultivation of carotenogenic yeasts in the presence of biological stress induced by selected strains of autotrophic microalgae
Sikorová, Pavlína ; Byrtusová, Dana (referee) ; Szotkowski, Martin (advisor)
Presented Master’s thesis was focused on biological and nutrient stress in cultivations of green microalgae and carotenogenic yeasts. The focus of interest was production of biomass in different types of cultivation media, production of metabolites (mainly carotenoids and chlorophylls) and also production of lipids and lipophilic substances. All types of aplied stress was used to lead to an increased production of biomass and metabolites. The theoretical part deals with introduction of individual genera of carotenogenic yeast and green microalgae. The types of cultivation stress were also described. In addition, the analytic methods for qualitative and quantitative analysis are also introduced. The experimental part was focused on the study of biomass, carotenoids, chlorophylls, coenzym Q, sterols and lipids production. Biological stress was induced by cocultivation of microalgae and yeasts together.Nutrient stress meant adding macroelements or waste oils to the medium. Yeasts of interest were Rhodosporidium toruloides, Rhodotorula kratochvilovae and Sporobolomyces pararoseus. Microalgae was represented by Desmodesmus acutus, Desmodesmus armatus, Scenedesmus obliquus, Desmodesmus velitaris, Desmodesmus communis, Coccomyxa sp. Chlamydomonas reinhardtii and Chlorella minutissima. Generally the most successful multicultivator experiment was cocultivation with yeast R. kratochvilovae. In the case of cultivation on waste oils, the best producers of biomass and metabolites were co-cultivation experiments with the yeast R. toruloides. In microalgal experiments, it was found that nutritional stress in the form of glycerol added to the medium had an inhibitory effect on the growth and metabolism of microalgae.
Effect of stress factors on carotenoid production in isolated soil algae strains
Očadlíková, Terezie ; Němcová, Yvonne (advisor) ; Nedbalová, Linda (referee)
Microscopic green algae produce a number of beneficial substances. The commercially used ones include mainly pigments, especially secondary carotenoids. While primary carotenoids are part of the photosynthetic apparatus, secondary carotenoids are produced only under certain specific conditions (e.g. high exposure to light, nitrogen deficiency). Secondary carotenoids have antioxidant properties that protect the cell from adverse effects. The strains currently in commercial use and the strains that are tested for potential use come almost exclusively from algal collections, so this thesis focuses on strains isolated from nature. Two strains of aeroterrestrial green unicellular algae, which showed potential of producing carotenoids, were found and isolated. These strains were identified as Tetracystis pulchra (clade Dunaliellinia) and Tetracystis sp., a strain related to Tetracystis tetraspora SAG 98.80, belonging to the clade Stephanosphaerinia. The culture conditions for T. pulchra were subsequently optimized and then the culture was subjected to a series of experiments, examining the effect of stress factors on carotenoid formation and accumulation. Specifically, the effect of nitrogen starvation, light intensity, temperature and UVA radiation was tested. It has been shown that especially the light...
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.
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.
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.

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