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Stanovení biologicky aktivních metabolitů jednobuněčných řas za různých kultivačních podmínek
Malyugina, Svetlana
This thesis studies effect of cultivation conditions on the production of secondary me-tabolites in the green microalgae Scenedesmus quadricauda. During the experiment was studied influence of pH, UVC radiation, light intensity and various temperature conditions on the amount of biologically active compounds (polyphenols, flavonoids, antioxidants). Metabolites were determined using biochemical analytical methods. The total content of polyphenols was determined using the Folin-Ciocalteu method, which is based on chemical reaction of phenols with Folin-Ciocalteu reagent. The total con-tent of flavonoids was determined spectrophotometrically using AlCl3.6H2O with the addition of NaNO2 and 1 M NaOH. The total antioxidant capacity (TAC) was deter-mined using phosphomolybdenun antioxidant assay. Antioxidant activity was stimu-lated by UVC radiation. The highest value being recorded when samples were exposed to UVC for 5 minutes. Light intensity and the temperature changes did not have significant effect on antioxidant activity of studied samples. There was an increase in TAC in samples cultured in acid pH medium (4 and 5). The content of polyphenolic and flavonoid compounds with high light intensity (3500, 4000 lx) and high tempera-tures (35 °C, 40 °C) decreased. Conversely, changes in pH and UV-C stimulate biosyn-thesis of both polyphenols and flavonoids. The greatest increase of these compounds was observed in the medium with pH = 4 and the time of exposure to UV-C for 5 minutes a day.
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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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Biosyntéza sekundárních metabolitů u Scenedesmus quadricauda v přítomnosti nanočástic
Kučerová, Dana
The theoretical part of thesis deals with microalgae, primary and secondary metabolism of plants, formation of the reactive oxygen species and origin of oxidative stress. Also it describes secondary metabolites, the characteristic of nanoparticles and impact on microalgae. The practical part deals with the impact of ZnO nanoparticles on secondary metabolism in Scenedesmus quadricauda. At first was observed the impact of nanoparticles on growth of microalgae. Then the content of photosynthetic pigments, total polyphenols, flavonoids and total antioxidant capacity was determined using spectrophotometric method. Also the content of chosen secondary metabolites was detected using HPLC. The growth of microalgae was stimulated by ZnO nanopartlicles during the first 4 days compared to control. Then the inhibition of growth was observed. The content of photosynthetic pigments decreased compared to control in samples with ZnO nanoparticles. Also the change of secondary metabolites, total polyphenols and flavonoids was observed.
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Utilization of algae in the food industry
Patloková, Kateřina
The thesis Utilization of algae in the food industry is primarily focused on characteristics and systematic classification of all significant genera of Cyanobacteria, microalgae and macroalgae, which can be directly consumed in fresh forms or culinary processed to various dishes. In addition, algae are also an important source of many substances that are often used in the food industry. Therefore the second part of the literary review contains chapters about further use as extraction of hydrocolloids, nutraceuticals or natural colourants. In this thesis, I am also attempting to inform users of alternative ways of healthy and ecologically sustainable eating by presenting many records of the beneficial health effects of algae. All scientific names of plants used in the thesis are taken from the concept of taxa published by Ruggiero, et al. in 2015 and from world-wide electronic publication accessed through World Register of Marine Species (Guiry & Guiry, 2019). The thesis is the culmination of my studies in Norway in 2017, which greatly enriched my knowledge on the field of algae production.
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Vliv inhibitorů BSO, Lycorine a AIP na biosyntézu sekundárních metabolitů jednobuněčné řasy Scenedesmus quadricauda
Rankić, Ivan
The theoretical overview summarize the characteristics of algae and their primary and secondary metabolism. It also deals with inhibitors of ascorbic acid, glutathione and polyphenolic compounds synthesis. The practical part studies the influence of selected inhibitors (BSO, Lyc, AIP) and CdCl2 on the secondary metabolites production and biomass growth in freshwater microalgae Scenedesmus quadricauda. The content of secondary metabolites (eg. caffeic acid, chlorogenic acid, salicylic acid, cinnamic acid, p-coumaric acid) was detected by HPLC-MS. Furthermore, the total antioxidant capacity, the total polyphenol content and the total flavonoid content was determined spectrophotometrically. All the inhibitors used, reduced S. quadricauda growth in comparison with control samples. The most pronounced inhibitory effect was observed in the samples treated with Lyc + Cd after 7 days of experiment. All the treated samples responded to the stress factors by altering metabolic pathways and inhibiting growth. As a result, there were changes in the composition and the amount of selected secondary metabolites versus the control samples. At the same time, in most cases, the biosynthesis of polyphenolic and flavonoid substances has been stimulated. The oxidative reduction equilibrium and the induction of oxidative stress were probably impaired.
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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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