National Repository of Grey Literature 27 records found  beginprevious18 - 27  jump to record: Search took 0.01 seconds. 
Production of pigments and lipid substances by microorganisms on waste substrates of the food industry
Hladká, Dagmar ; Němcová, Andrea (referee) ; Szotkowski, Martin (advisor)
The presented study is focused on production of carotenoids, lipids and other substances by carotenogenic yeasts and autotrophic algae. Studied strains were cultivated in media with different composition, including waste substrates from food industry. Studied strains were cultivated under stress conditions to enhance the production of desired metabolites. The theoretical part deals with the information about yeasts and algae, with the information about monitored metabolites such as lipids, carotenoids, ergosterol, ubichinon or chlorophyll. Furthermore, the theoretical part deals with possible methods of metabolite analysis. The experimental part deals with the description of cultivation of yeats and algae. Also experimental part is focused on the description of individual methods. The result part deals with comparition of production of biomass, metabolits and lipids. The selected strains of yeast were Sporidiobolus pararoseus, Sporidiobolus metaroseus, Sporobolomyces roceus, Phaffia rhodozyma and Dioszegia hungarica. The selected strains of algae were Desmodesmus acutus, Desmodesmus quadricauda, Scenedesmus dimorphus and Chlamydomonas reinhardtii. We were optimized conditions for metabolites and lipids production. Optimal medium, which contained coffee hydrolyzate was with carbon to nitrogen ratio C/N 25. Nitrogen in higher concentration had negative effect on production of lipids. The most suitable strain for effective use of nitrogen in different concentrations was Chlamydomonas reinhardtii. The most suitable strain of yeast for effective use of coffee hydrolyzate was Sporidiobolus metaroseus.
Optimization of extraction of pigments from yeast and algae cells
Šimanský, Samuel ; Mikulíková, Renata (referee) ; Márová, Ivana (advisor)
The presented diploma thesis deals with the extraction and storage stability of lipophilic pigments produced by selected strains of yeasts and algae. In this thesis, there was studied the influence of the selected solvents on the efficiency of extraction, as well as the effect of ambient temperature on the stability of the pigments during storage. The work is divided into two main parts, theoretical and practical part. In the theoretical part knowledge about algae, yeasts and their cultivation parameters is summarized. Furthermore, some information regarding the selected lipid metabolites, their properties and possibilities of application in various branches of industry is mentioned. The practical part deals with the preparation of extracts and stability tests. Extracts were prepared from selected biomass samples in solvents suitable for applications in food industry or cosmetics (ethanol and hexane). Subsequently, the long-term stability tests lasting 4 months and short-term stability tests lasting a total of 28 days were performed on these extracts. The pigments were determined by HPLC and spectrophotometrically, the fatty acid content was determined by GC. For the extraction of pigments from biomass, in the most cases ethanol appears to be the optimal solvent. However, for lipid extraction from biomass, hexane appears to be the optimal solvent for a significant number of samples. In most samples, storage in the freezer showed the most favourable effect on pigment stability, but some samples showed comparable stability even when stored in the refrigerator.
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.
Production of lipids and lipid-soluble compounds by some yeasts and algae
Šimanský, Samuel ; Rapta, Marek (referee) ; Márová, Ivana (advisor)
The submitted bachelor thesis focuses on production of lipids and lipid-soluble compounds by selected strains of carotenogenic yeasts, autotrophic algae and cyanobacteria. Different forms of stress were applied on selected strains and its influence was subsequently compared. The theoretical part deals with the processing of knowledge about selected strains of yeast, algae and cyanobacteria. There are also mentioned the selected metabolites (lipids, carotenoids, ergosterol, ubiquinone and chlorophyll) and the possibilities of their determination. The experimental part deals primarily with the influence of nutritional stress on the production of selected metabolites and the yeast biomass, namely their growth properties on waste fat. Furthermore, there was monitored the effect of elevated and reduced temperature on the cultivation of yeasts, algae and cyanobacteria. Osmotic stress experiments were also carried out by the addition of NaCl. As the most suitable strain for decomposition of the waste fat was selected Sporidiobolus pararoseus, particularly because of its high content of carotenoids, ergosterols and ubiquinone in biomass. Changes in temperature, or increased osmotic pressure had in the most cases a negative effect on biomass production.
Characterization of individual phases of cultivation of red yeasts
Valentová, Lucie ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with the problematic of metabolic activity and morphology of several biotechnologically significant red yeasts - Rhodotorula glutinis, Sporobolomyces shibatanus and Phaffia rhodozyma during the cultivation time. These yeasts were cultivated on glucose medium, during the cultivation samples were taken for the analysis of produced metabolites. The amount of -carotene, astaxanthin, coenzyme Q and ergosterol were monitored. The amount of biosynthesised lipids and fatty acid profile was also investigated. HPLC/PDA and GC/FID were used for the analysis of these metabolites. Yeasts were cultivated 56 hours (they reached early stationary phase). The highest production of carotenoid pigments showed Phaffia rhodozyma (1856.58 g/g), 42 % of this amount represents -carotene. The highest lipids biosynthesis efficiency was reached by Rhodotorula glutinis. To study the inner structure of yeast cells the Fluorescence Life-time Imaging was used, the Autofluorescence of carotenoids and fluorescence of lipid bodies induced by lipophilic dye Nile red was observed. This method is very useful for imaging cell inner structure (membranes, some kinds of organelles). The changes that the cell undergoes during its evolution could be quantified too. The relationship between the level of carotenoid concentration, membrane rigidity and metabolic shift was found.
Use of carotenogenic yeasts to production of lipid soluble metabolites
Mariničová, Veronika ; Hlaváček, Viliam (referee) ; Márová, Ivana (advisor)
Carotenoids are fat-soluble chemical compounds that occur as natural pigments in many plants and protect them from sunlight. Lipids are also essential lipophilic substances and they are part of biomembranes. Their main function is primarily to serve as a power supply for the cell, protective function and thermal protection against adverse environmental influences. This bachelor thesis deals with cultivation of selected carotenoid yeast genes, subsequent isolation of carotenoids and other lipid substances, which can be used as a source of potentially beneficial substances for the pharmaceutical or cosmetic industry. The theoretical part deals with the description of carotenoid yeasts, chemical composition and biosynthesis of the metabolites produced, and description of the methods used for their determination. The experimental part is focused mainly on the production of lipid substances by various strains of yeasts using cheap waste substrates and the application of exogenous stress (nutritional stress) to the biotechnological overproduction of selected metabolites using the modification of the production medium. The content of carotenoids, ergosterol and coenzyme Q was analyzed by high performance liquid chromatography with a PDA detector. The lipids accumulated in yeast cells were determined by gas chromatograph with a FID detector. In this work the strains of Sporobolomyces pararoseus, Sporobolomyces metaroseus, Rhodotorula glutinis and Cystofilobasidium infirmominiatum were studied. As waste substrates and carbon sources were used glycerol, which is produced as a waste product in the production of biofuels and whey as an unusable product in dairy technology. The best production on waste substrates was observed in the strains Rhodotorula glutinis and Cystofilobasidium infirmominiatum.
Comparison of growth and productivity of autotrophic algae and red yeasts
Kouřilová, Xenie ; Rapta, Marek (referee) ; Márová, Ivana (advisor)
The submitted bachelor thesis focuses on the comparison of growth and productivity of red yeasts Rhodotorula aurantiaca and Xanthophyllomyces dendrorhous and autotrophic algae Chlamydomonas reinhardtii and Chlorella vulgaris under different physical conditions. The theoretical part contains the characteristics of selected micro-organisms, stress factors caused by temperature, radiation, combination of aeration and radiation and osmotic stress. Furthermore, knowledge on metabolites and the possibilities of their analysis are mentioned. Physical stresses, namely 2%, 3%, 4% and 5% solution of sodium chloride, intense radiation, absence of lighting, 8°C and 30°C, were applied to selected strains in cultivation. Under these conditions, changes in production of carotenoids, fatty acids, ergosterol, ubiquinone and proteins were being observed. A significant inhibitive effect on all the above mentioned micro-organisms was brought about by the use of 5% solution NaCl. The highest production of metabolites with X. dendrorhous was discovered when 4% solution of NaCl was used. R. aurantiaca demonstrated higher substance utilization at 30°C. For the selected algae strains were the used stresses lethal. Within the cultivation process, the possibilities of co-cultivation of yeasts and algae were also tested, which will be the subject of further studies.
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.
Analysis of nicotin content in some products
Pražáková, Jana ; Kočí, Radka (referee) ; Márová, Ivana (advisor)
This diploma thesis deals with the determination of nicotine in different products. The theoretical part summarizes review on nicotine, smoking and opportunities how to quit. In the practical part a method for the determination of nicotine by HPLC / PDA was optimized. As the most suitable stationary phase was selected a Kinetex 5u C18 100A 150 x 4.6 mm column, as the optimal mobile phase was chosen a pure methanol with a flow rate of 1 ml min-1 and a temperature of 25 °C. For the analysis of nicotine were chosen: 18 kinds of cartridges for electronic cigarettes, two kinds of nicotine gum, nicotine spray, nicotine pastilles, nicotine orodispersible film and ten species of classic cigarettes. For each type of product the most appropriate method for extracting nicotine and its subsequent analysis by HPLC / PDA was found. For tobacco 24 hour extraction in methanol and 10s ultrasound was selected. The nicotine spray and electronic cigarette refills without flavours were only diluted with methanol. Flavoured refills were first diluted by sodium hydroxide and then with methanol. For chewing gums, pastilles and nicotine film extraction with 5% sodium hydroxide was chosen. In this study also new experimental nicotine product was designed. Nicotine has been encapsulated in alginate-starch material to form small gel particles. As the most suitable medium for storage the water medium was determined.
Preparation and characterization of alcohol-free beers with different flavour
Benešová, Pavla ; Vávrová, Milada (referee) ; Márová, Ivana (advisor)
This diploma thesis deals with preparation and characterization of alcohol-free beers with different flavours. Five flavoured and four pure, commercially available beers were tested. Three alcohol-free beers were then selected and used for preparation of flavoured beers. Ingredients used for production of flavour were honey, raspberry, ginger and cranberry. Analysis was focused mainly on substances of phenolic nature. Flavoured beers were also tested in sensory analysis. Ingredients used for flavouring of beers and production of both alcoholic and alcohol-free beers are described in theoretical part of the thesis. Analysis of polyphenols, flavonoids, technological characteristics and anthocyanins was performed using spectrophotometric method. Phenolic substances were identified and quantified by HPLC/PDA. Ascorbic acid was analysed by HPLC-NH2/UV. Results proved an increase of polyphenols, ascorbic acid and anthocyanins during flavouring of alcohol-free beers in dependence of used ingredients. Sensory analysis showed that as the best rated was the Staropramen beer with raspberry flavour. On the contrary, flavoured Bernard beers were poorly rated.

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