National Repository of Grey Literature 77 records found  previous11 - 20nextend  jump to record: Search took 0.01 seconds. 
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.
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.
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.
Analysis of glucans in plant and microbial samples
Vít, Radek ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
The aim of the diploma thesis is study of glucans production in selected species of yeasts, algae and plants. Cultivation conditions for yeast strains were performed to gain increased production of glucans under different temperature conditions and in media of different composition. Into the set of tested yeasts species strains Saccharomyces cerevisiae (CCY 6646), Sporidiobolus pararoseus (CCY 19-9-6), Phaffia rhodozyma (CCY 77-1), Rhodotorula glutinis (CCY 20-78-26) and Cystofilobasidium infirmominiatum (CCY 17-18-4) were enrolled. Saccharomyces cerevisiae was cultivated as a control strain because of its verified production of -glucans. -glucans were determinated by the enzyme kit K-YBGL Megazyme. For comparison, algal strain Euglena gracilis (CCALA 349), some species of mushrooms (shiitake, oyster mushroom, garden champignon and Jew’s ear) and cereals (wheat, rye, oats, rice and barley) were analysed too. Further, fatty acid content in the yeast cells was determined by the GC/FID. The best producer of yeast -glucans was R. glutinis CCY 20-7-26, which showed the highest biomass production (12-14 g/l) and also a relatively high amount of -glucans (25-30 %), in cultivation at 15 °C in a medium containing yeast extract in combination with ammonium sulphate. The presence of -glucans has been demonstrated in the microalgae, Euglena gracilis CCALA 349, as well as in samples of higher fungi and cereals.
Production of beta-glucans by some yeasts and algae
Veselá, Markéta ; Kočí, Radka (referee) ; Márová, Ivana (advisor)
Several yeast strains and microalgae were selected for this diploma thesis. -glucans, lipids, carotenoids, ergosterol and coenzyme Q were determined in selected producers, and the cultivation conditions for yeast strains were optimized to gain enhanced production of -glucans. Microalgae cultivations were carried out according to the instructions of the Collection of Autotrophic organisms (CCALA). Selected microalge strains include Desmodesmus acutus, Dunaliella salina, Arthrospira maxima and Cyanothece sp. Selected yeast species include Rhodotorula glutinis, Cystofilobasidium macerans and Sporidiobolus metaroseus. Edible yeast Saccharomyces cerevisiae was cultivated to compare with other yeast strains because of it's verified production of -glucans. -glucans were then determined by the enzymatic kit K-YBGL Megazyme, carotenoids, ergosterol and coenzyme Q were analyzed by HPLC/PDA and fatty acids were analyzed by GC/FID. The best producer of yeast -glucans was R. glutinis and S. metaroseus, and the best conditions for the production of -glucans and other metabolites was the C/N ratio of 70. Within the microalgae species, only -glucan production was observed, the best producer was D. acutus.
Photobioreactor aeration optimization using image analysis
Hruška, Kryštof ; Létal, Tomáš (referee) ; Naď, Martin (advisor)
This diploma thesis summarizes the knowledge about microalgae, their use, cultivation methods and obstacles that prevent their wider use. In the practical part of the work, a device was designed, constructed, and programmed. This device can analyze the bubbles of the tubular photobioreactor and, based on the obtained data, control its aeration. The Python programming language was used to create the program and the OpenCV library was used to analyze the photographs. The bubble detection is based on the edge detection and the subsequent refinement. The data obtained from the analysis are displayed on the device screen and the data are also stored in a csv file. The discussion lists possible improvements and lessons learned during the creation of this device.

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