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Sekundární metabolismus jednobuněčných řas v přítomnosti nanočástic =: Secondary metabolism of unicellular algae in the presence of nanoparticles /
Strejčková, Aneta
This work summarizes important information about microalgae and nanoparticles. It deals with the possible mechanism of the effect of nanoparticles, describes some of the most used nanoparticles and summarizes available information on their toxic impact on algae. The main research part deals with the influence of nanoparticles on the secondary metabolism of uni-cellular microalgae, focused mainly on phenolic compounds and their role in the antioxidant response of microalgae. The level of oxidative stress was investigated by evaluating biomass growth, total antioxidant capacity and concentration changes of compounds involved in the glutathione-ascorbate cycle. This work also focused on carotenoids, chlorophylls, vitamins, that play an important role as antioxidants, and substances of the methionine cycle. Total quantities of flavonoid compounds and polyphenols were determined by spectrophoto-metric method. The same method was also used to monitor algal growth, total antioxidant capacity, chlorophyll and carotenoid content. The content of individual phenolic compounds, as well as the vitamins and compounds of glutathione-ascorbate and methionine cycles, was determined by liquid chromatography with mass spectrometry detection.
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MikroRNA jednobuněčných řas a rostlin a vliv abiotických stresových faktorů =: MicroRNA in plants and unicellular algae under abiotic stress factors /
Koláčková, Martina
Stress signaling pathway regulates proteins which are critical for reprogramming of metabolic synthesis and gene expression to achieve homeostasis and cellular stability under stress conditions. The understanding of stress signaling mechanism and response will increase the ability to improve plant‘s oralgal resistance to stress. The theoretical part summarizes the current knowledge of biosynthetic pathway and miRNA roles and presents selected model organisms (Chlamydomonas, Arabidopsis). As well, it introduces abiotic stress and seeks links between abiotic factors, secondary metabolites and miRNAs. The experimental part deals with selected abiotic factors [lycorine, UV-C radiation, ZnSe quantum dots (QDs), CO2] and their influence on Chlamydomonas reinhardtii and Arabidopsis thaliana. It has been shown that 100 and 250µM ZnSe QDs in the form of foliar feeding caused oxidative stress in the leaves without morphological changes in Arabidopsis thaliana. Additionaly, 250µM concentration inhibited the viability of Agrobacterium tumefaciens, a Gram-negative bacterium infecting plants, by 60 %. Furthermore, the regulatory biochemical, molecular and post-transcriptional pathways of Chlamydomonas reinhardtii response to UV-C radiation and lycorine were identified. Further, three specific miRNAs (Cre06.g281600, Cre06.g30900, Cre16.g662600) have been studied in connection with carbon concentrating mechanism (CCM) in Chlamydomonas reinhardtii. Expression of mentioned miRNAs had a positive correlation with target mRNA and revealed the potential regulatory role of miRNAs during CCM adaprion and possibility to increase the efficiency of photosynthesis. Despite, the role of epigenetics including miRNA interference is still unclear in the unicellular algae.
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Epigenetické mechanismy vs. RNA řízená editace genů v jednobuněčných zelených mikrořasách =: Epigenetic mechanisms vs. RNA directed gene editing in unicellular green microalgae /
Bačová, Romana
The first part of the thesis is devoted to the study of an epigenetic regulation of genes in unicellular green microalgae. The influence of environment on DNA methylation level, histones modifications, chromatin structure and RNA interferences are described as well as their effect on metabolome. The work focuses more closely on the effect of the demethylation reagent 5-azacytidine and CdCl2 on the amount of 5-mC and metabolites of the methionine cycle in Chlamydomonas reinhardtii and Scenedesmus quadricauda in the context of the production of secondary metabolites. The second part of the thesis is focused on genetic engineering. Specifically, the CRISPR/Cas9 method was used as RNA-directed gene editing in the model organism, C. reinhardtii. An optimization of the cpFTSY chloroplast gene was performed, demonstrating phenotypic change in mutated colonies. Furthermore, CRISPR/Cas9 was used to edit the adiposuppressor gene WDTC1. For both genes we obtained mutants whose DNA was repaired using both NHEJ and HDR. Using the fluorescence NileRed analysis, two ?WDTC1 colonies demonstrated an increased TAG content. Epigenetic mechanisms should be studied more to understand the adaptation of microalgae to stress and the environment, providing valuable information for knowledge of metabolic pathways, transcription factors. This information can be used for controlled gene editing, resulting in increased amounts of product for the same or better biomass growth.
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Odstraňování nutrientů řasovými biofilmy během dočišťování odpadních vod
Sukačová, Kateřina
Presented PhD theses deals with evaluation of use of algal biofilms for nutrients removal from wastewater. The integral part of research was estimation of the comprehensive benefit of the presented technology, including biomass production and phosphorus recovery. The algal biofilm was able to remove 98 % of phosphorus after 24 hours when the PO4-P concentrations in inflowing water ranged from 3 to10 mg.L-1. Different patterns of phosphorus and nitrogen removal were observed. Daily quantity of removed NO3-N ranged from 2 % to 25 % and was highly depended on solar irradiance. The studied biofilm system has a high efficiency for phosphorus removal and, therefore, has great potential for integration into wastewater treatment processes.
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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.
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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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