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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.
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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).
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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.
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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.
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