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PRODUCTION OF BETA-GLUCANS AND OTHER POLYSACCHARIDES BY YEAST AND MICROALGAE
Byrtusová, Dana ; Kráčmar, Stanislav (referee) ; Kovalčík, Adriána (referee) ; Márová, Ivana (advisor)
Beta-glukany jsou polysacharidy složeny z monomerů D-glukózy. V dnešní době se -glukany těší zvýšené pozornosti zejména kvůli imunomodulační aktivitě a využitelnosti ve farmaceutickém a potravinařském průmyslu. Saccharomyces cerevisiae je dodnes jediným kvasinkovým zdrojem požívaným v biotechnologické produkci. Avšak některé kvasinky z oddělení Basidiomycetes, které jsou schopny produkce lipidů a karotenoidů, mohou být využity rovněž jako alternativní zdroj -glukanů. Dizertační práce se zabývá možností a optimalizací produkce -glukanů a dalších mikrobiálních sacharidů u karotenogenních kvasinek a mikrořas. Testovány byli zástupci rodů Rhodotorula, Sporobolomyces, Cystofilobasidium a Dioshegia. Z nekarotenogenních kvasinek byly do screeningu zařazeny kvasinky rodu Metschnikowia, askomycetní kvasinky a z mikrořas zástupci zelených a červených řas. Experimentální část cílí rovněž na možnosti koprodukce dalších metabolitů, jako jsou lipidy, pigmenty a extracelulární polymery. První část experimentu se zabývá vlivem čtyř C/N poměrů (10:1, 40:1, 70:1 a 100:1) na produkci biomasy, -glukanů, karotenoidů a lipidů. Ze všech testovaných kmenů, S. cerevisiae CCY 21-4-102, C. infirmominiatum CCY 17-18-4, P. rhodozyma CCY 77-1-1 a R. kratochvilovae CCY 20-2-26 vykazovaly nejvyšší produkci -glukanů a byly proto vybrány k podrobnější optimalizaci, zejména osmotického stresu, teploty a zdroje dusíku v kultivačním médiu. Dodatečně, kmen R. kratochvilovae CCY 20-2-26 je schopný produkce extracelulárních glykolipidů a S. pararoseus CCY 19-9-6 extracelulárních polysacharidů. Následně bylo stanoveno množství -glukanů u dalších dvanácti kmenů S. cerevisiae a rovněž možnost produkce polysacharidů u mikrořas.
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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.
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Influence of stress and nutritional conditions on carotenogenic yeast and microalgal metabolism
Sikorová, Pavlína ; Byrtusová, Dana (referee) ; Szotkowski, Martin (advisor)
This bachelor thesis describes the infuence of biological stress (co-cultivations) on the growth and metabolism of selected carotenogenic yeasts and microalgae. The metabolites of these microorganisms are chlorophyll and carotenoids, which are natural pigments and antioxidants. In theory, co-cultivation is a cultivation where microorganisms mutually support each other in the growth and production of metabolites. This would cause the increased production of previously mentioned chlorophyll and carotenoids. The theoretical part of the work is focused on the description of selected species of yeasts and microalgae and further discusses in more detail, the topics of stress factors depending on the growth and metabolism of microorganisms. The experimental part then deals with different types of cultivation and cocultivation and tries to optimize the production media and find the best symbiotic yeasts and microalgae. Furthemore the issue of different ratios of microorganisms in co-cultivations is also addressed here. The cultivated yeasts strains were Rhodotorula kratochvilovae, Rhodosporidium toruloides and Phaffia rhodozyma. And microalgae strains were Desmodesmus acutus, Desmodesmus quadricauda, Coccomyxa sp., Chlorella sorokiniana, Chlamydomonas reinhardtii and Scenedesmus obliquus. Cultivated cyanobacterium was Synechoccocus nidulans. The most successful co-cultivation experiment was the one with R. kratochvilovae and yeast Desm. quadricauda. This experiment was very succesful in all aspects.
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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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