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Vliv železa a jeho bioakumulace v sinici Spirulina a mikrořase Chlorella
Koláčková, Kristýna
Iron is a trace element playing a key role in a number of metabolic pathways important for all living organisms. Iron deficiency is one of the most widespread problems in human nutrition. In order to possibly use Spirulina and Chlorella as dietary supplements for people suffering from iron deficiency sideropenic anemia, the effect of different concentrations of iron in the medium (0 mg/L, 5 mg/L and 10 mg/L) on its amount in the biomass was investigated. The optimal amount of Fe2+ in the medium was determined using spectrophotometric determination of optical density (OD) and iron content in Arthrospira maxima and Chlorella vulgaris biomass, which was determined by atomic absorption spectrometry (AAS). Expression analysis, performed in a model organism with a sequenced whole genome, Chlamydomonas reinhardtii, revealed the effect of selected concentrations of Fe2+ on the genes of the oxidative stress regulatory pathway. The results of the above analyzes show what are the optimal levels of iron cations for the growth of the studied organisms and its accumulation in them. The effect of iron in the chosen form, its assimilation and bioaccumulation in the cyanobacteria Spirulina and Chlorella microalgae was thus clarified.
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Effects of chronic exposure to low-dose ionizing radiation on Chlorella vulgaris
Mikša, Lukáš
Ionizing radiation is one of the fundamental abiotic stress factors that is constantly interacting with life on our planet. The topic of the effects of high to extremely high doses of ionizing radiation on living organisms, in general, is quite well studied but little is known about the impact of low dose ionizing radiation on living organisms, especially when it comes to microalgae, which are not just a crucial part of aquatic ecosystems on our planet but also nowadays they serve as a promising crop of the future that can play a vital role in space agriculture, where radiation background is significantly higher than the average radiation background on Earth. A series of experiments were conducted to study the long-term effects of elevated natural ionizing radiation using compartmented growing containers containing radioactive minerals emitting predominantly low-LET radiation (β and γ). The goal was to evaluate the long-term effect on the microalgae cultures after 4 weeks of cultivation under constant irradiation. The chronic irradiation induced radiation adaptive response resembling radiation hormesis. The irradiated microalgae displayed higher viability and biomass accumulation than the control group. Additionally, it was observed that proline levels significantly decreased after 14 days of irradiation, while the flavonoid content increased.
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Continuous electrocoagulation of Chlorella vulgaris in a novel channel-flow reactor
Lucáková, Simona
In our laboratory, we employed an electrocoagulation process with iron sacrificial anode leading to the separation of Chlorella vulgaris cells with high efficiency and at the same time acceptable low contamination of separated biomass by iron. Comparing to only centrifugation, the total energy costs of harvesting using electrocoagulation as a pre-concentration step prior to centrifugation were reduced by more than 80%. After extensive study of the influence of relevant process parameters.
Plný tet:  PDF
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Vliv nanočástic na produkci karotenoidních a polyfenolických látek u Chlorella vulgaris
Zronková, Veronika
Microalgae are increasingly involved in the diet due to their beneficial effects on human health and therefore they are more often studied. Nowadays, there is a trend of using nanotechnology. The undesirable effects of copper oxide nanoparticles (CuO) attract more and more attention today. Since, there is an increasing demand for fossil fuels and simultaneously the amount of CO2 is increasing in the air, microalgae could serve in future as renewable fuels thanks to its rapid grow properties. In the diploma thesis, I dealt with the amount of carotenoid and polyphenolic substances in the algae Chlorella vulgaris after the influence of CuO nanoparticles. Experimental part of this work summarizes the results, revealing that CuO nanoparticles caused decrease of chlorophyle a by up to 60 % with CuO nanoparticles concetration of 25 mg/l, together with significant decrease of chlorophyle b and carotenoids. The amount of polyphenols and flavonoids in biomass has been changed only minimaly. In contrast, with usage of increasing concentration of CuO nanoparticles I found out by the SPOT test the increase of biomass in algae. Significant changes in selected secondary metabolites has been observed. The greatest statistically significant (p<0,01) growth with concetration 5 mg/l (1,08 ± 0,05 µg/g dry weight) has been observed for pOHbenzaldehyde, with increase by 42 % compared to control. In contrast rapid decrease has been noted with concentration 25 mg/l (0,06 ± 0,04 µg/g dry weight)
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Electrocoagulation of Microalga Chlorella vulgaris.
Lucáková, Simona
This study is focused on harvesting of Chlorella vulgaris, well-known microalga with wide range of use in nutrition and health care. Harvesting (separation of cells from a culture medium) is an important part of the production process. It was estimated that approximately 30% of the production costs is the cost of biomass separation. Harvesting densities of photoautotrophic microalgae are relatively low (the final dry biomass concentrations usually vary in range 0.5–3 g/L). Centrifugation is the most frequently used method of harvesting, but it is economically inefficient due to its high process cost.
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Coagulation of different kinds of algal organic matter
Novotná, Kateřina ; Načeradská, Jana ; Barešová, Magdalena ; Janda, V. ; Pivokonský, Martin
This study focused on coagulation of different algal organic matter (AOM) fractions, especially on its non-proteinaceous fraction. It was derived from cellular organic matter of Chlorella vulgaris, a freshwater algae. Two different Al-based coagulants were employed, i.e. alum and pre-hydrolyzed polyaluminim chloride (PACl). The highest coagulation efficiency was obtained at pH around neutral (pH 7.1-7.5 for alum and pH 7.6-8.0 for PACl) at relatively high dosages of coagulant (8 and 10 mg·L-1 as Al for alum and PACl, resp.). However, the maximum removal reached under the optimized conditions was only approximately 20%. The coagulation behaviour and efficiency of non-proteinaceous matter greatly differ from AOM peptide-proteins, which is discussed in the study.
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Effect of algae feeding on selected qualitative indicators of milk of small ruminants
Novotná, Klára ; Stádník, Luděk (advisor)
Milk fat is one of the most important components of goat milk. Another benefit of goat milk fat is its better digestibility in comparison with cow milk, which is caused by the smaller size of lipid micelles. Goat milk fat contains more lower fatty acids (caproic, caprylic and capric), which affect the production and processing of milk and cause specific flavor of goat's milk and dairy products. In recent years, the subject of many studies the possibility of increasing the content of other health beneficial fatty acids in goat milk, such as conjugated linoleic acid (CLA) and omega-3 and omega-6 polyunsaturated fatty acids. Animal nutrition is a significant factor how to achieve these changes in the fatty acid profile of milk fat. For these purposes can be used as additives for certain species of algae which are the source of nutritionally valuable lipids with a high content of polyene fatty acids, especially omega-3 and omega-6 fatty acids. The ability to change the composition of goat mikl fat, represents an opportunity for the development of new products. Functional foods, such as milk and dairy products enriched with omega-3 and omega-6 fatty acids. The aim of this work is to determine what effect the addition of selected algae (Chlorella vulgaris and Japanochytrium sp.) On milk production and representation of the components of milk, focusing on the composition of milk fat and fatty acid profile in goat milk. Attention was paid to reduction of saturated and increase the proportion of nutritionally beneficial unsaturated fatty acids, in particular n-3 polyunsaturated fatty acids.
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Effect of Microalgae Cell-Disruption Method on Extraction Yield of Fatty Acids
Rousková, Milena ; Sobek, Jiří ; Maléterová, Ywetta ; Kaštánek, František ; Šolcová, Olga
Freshwater algae are a source of unsaturated fatty acids, essential for healthy development of the human body. Green microalga chlorella vulgaris was selected for laboratory extraction of the lipid fraction, especially with regard to the content of fatty acids. Owing to that microalgae consist of individual cells surrounded by the thick cell walls, several cell-disruption methods were applied to increase the lipid extraction efficiency. The concentrated algal biomass suspension was disrupted using methods as follows: drying, lyophilisation, microwave treatment, sonication and high-pressure shock. Mild extraction conditions (room temperature, absence of light, environmental friendly solvent system) were applied.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22014092610180 - PDF
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