National Repository of Grey Literature 165 records found  beginprevious136 - 145nextend  jump to record: Search took 0.00 seconds. 
Condition dependence of secondary ornamentation and mate choice in Grey Partridges
Gabrielová, Barbora ; Albrecht, Tomáš (advisor) ; Sedláček, Ondřej (referee)
This study focuses on relationships between individual condition, measures of ornament expression and mate choice in the Grey Partridge (Perdix perdix). It is based on the correlative data as well as results of manipulative experiments. I found positive correlation between the size of melanin- and carotenoid-based ornaments in partridges. The size and the redness of the carotenoid skin patch, and the size of the melanin-based feather ornamentation were associated with several measures of immunity and overall body condition (complement activity, ratio of immature erythrocytes, heterophil/leucocyte ratio, response to novel antigen). Furthermore, data from natural populations indicate that the expression of carotenoid-based ornamentation is associated with sexual attractiveness (measured as the ability to obtain a social mate) in partridges. Data from captive individuals indicate that carotenoid supplementation improves the redness of carotenoid-based ornament, while the stimulation of the immune system under increasing concentrations of supplemented carotenoids has no measurable effect on condition and physiological state. This seems to contradict predictions of the 'Carotenoid maintenance hypothesis'. Overall, results better understanding the role of carotenoid and melanin-based ornamentation in signaling...
Response of different genotypes of Zea mays L. and Vicia faba L. treated with brassinosteroids to water deficit
Kuklíková, Radka ; Rothová, Olga (advisor) ; Hnilička, František (referee)
This work monitors the response of plants to the application of a solution of synthetic brassinosteroid (5-fluor-3α,17β-dihydroxy-5α-pregnan-6-on) under drought stress conditions and subsequent restoration of water availability. The response of two plant species was monitored under six-day period of cessation of watering and under six-day period of renewed optimal water supply. The experiments were carried out on plants with different type of photosynthesis - C3 plant Vicia faba L. and C4 plant Zea mays L.. For both plant species, three varieties/genotypes were used. Photosynthetic, morphological and developmental characteristics were monitored. The brassinosteroid treatment influenced more the morphological than the photosynthetic characteristics. The content of photosynthetic pigments was influenced more than the chlorophyll fluorescence parameters. The differences in morphological characteristics between individual varieties/genotypes were observed. The response to the application of brassinosteroid was observed especially for drought-sensitive variety/genotype. Application of brassinosteroid caused increase of the dry mass of leaves and roots, the height to leaf , the height of the whole plant and its increment under stress and post-stress periods in both plant species. The content of...
Inter- and intraspecific variability in Vicia faba L. and Zea mays L. response to water deficit
Fridrichová, Lenka ; Holá, Dana (advisor) ; Zelenková, Sylva (referee)
This work monitors the response of plants to water deficit and subsequent restoration of water availability with the aim to expand our knowledge about plant behaviour during and after drought stress from the perspective of two plant species with a different type of photosynthesis. A particular attention was paid to the intraspecific differences and their possible changes during stress and post-stress periods. The plant response was monitored as the changes of selected photosynthetic, morphological and developmental characteristics caused by the cessation of watering for six days followed by a six-day period of renewed optimal water supply. The experiments were carried out on plants with different types of photosynthesis - C3 plant Vicia faba L and C4 plant Zea mays L.; for both plant species, three varieties / genotypes were monitored. The response of both plant species to insufficient water supply differed by the extent of changes in relative water content (RWC), chlorophyll fluorescence parameters, the dry mass of individual leaves (developed during the stress period), the ratio between the aboveground dry mass and dry mass of roots. In drought-stressed plants, downward trend in RWC was observed, as well as the increase of the minimum yield of chlorophyll fluorescence in dark-adapted leaves (F ),...
Excited States of Carotenoids and Their Roles in Light Harvesting Systems
KEŞAN, Gürkan
Carotenoids are an extensive group of natural pigments employed by a majority of organisms on earth. They are present in most organisms, including humans, but can be synthesized only by plants and microorganisms. They perform two major roles in photosynthesis, often in partnership with the more prevalent chlorophylls (Chls) / bacteriochlorophylls (BChls): light-harvesting and photoprotection. Carotenoids absorb radiation in a spectral region inaccessible to Chls and BChls and transfer the absorbed energy to (B)Chls which, in turn, funnel it into the photosynthetic reaction center (RC). It is determined that the structures and dynamics of excited states of carotenoids found in photosynthetic proteins provide an explanation of their roles as light-harvesting and photoprotective agents. The conjugation length and the type of carotenoids play a big part in understanding the energy transfer from carotenoids to Chls and BChls, because excited-state properties of carotenoids are affected by number of conjugated C=C bonds and their structures. An accurate description of these states is, therefore, the crucial first step in explaining carotenoid photochemistry and understanding the interactions between carotenoids and other molecules in photobiological processes. The research in this thesis, femtosecond ultrafast transient absorption spectroscopy was used to study the light-harvesting function of carotenoids both in solvent and protein environment. The findings were supported with computational methods. Based on spectroscopic indications, the light-harvesting function of carotenoids has a bearing on their structures, and specific light-harvesting strategies are explicitly dependent with the structure of the light-harvesting complexes.
Biologicky aktivní látky v medu
Ošťádalová, Ilona
This thesis is introducing us a theme of "Biologically active compounds in honey". The first part is introducing characteristic of honey, mostly types not only domestic, but also from abroad and their spesifics. As next, the reader is shortly breefed about history of a use of honey for medical purposes such as skin treatments, inflammations, cancer and other diseases. At the end of this chapter there is a honey content described. Next chapter is explaining a term of biologically active compounds, describing some of them, their amount and comparing these amounts to others coming from different groceries. Also there is spoken about their positive influence on human health and methods of their laboratory determination.
Barevné pšenice - genetická determinace a technologické využití
Andrýsková, Martina
The aim of this work entitled "Coloured wheat - genetic determination and technological processing" is to select the most appropriate way of treatment of coloured wheat (Triticum aestivum L.) in food industry. The grown common wheat has red coloured grain. However, there are several genotypes of wheat with different, genetically determined, grain colour: purple, blue, yellow and white. The purple and blue forms content different anthocyanins, the yellow forms the higher level of carotenoids. These compounds are known for their antioxidant effect. Therefore the different colour grains can be used in food industry for the production of new products which could be not only attractive for consumers but they would be also good for their health. In different grain tissues there are different amounts of coloured substances that affect their content in flour and meal. Hence there is necessary to choose the suitable grain tissue. Moreover the technological proces should be modify because of low stability of pigments. This work also deals with genetic determination of different coloured grain of wheat and with the possibilities of healing claims and food labeling.
Významné obsahové látky u vybraného druhu zeleniny
Jacková, Zdenka
Bachelor thesis is focused on description of important content substances in Daucus carota L. Experimental part is focused on monitoring and evaluating of content substances in nine picked cultivars: 'Kardila', 'Rubína', 'Karkulka', 'Jolana F1', 'Kráska', 'Katlen', 'Jarana F1', 'Koloseum F1', 'Jitka F1'. Vitamin C, dry matter, antioxidants, minerals, refractometric dry matter, nitrates, carotenoids and roughage were determined. Aim was to summarize all results from experiment and compare them with other literary sources. The best results had 'Kráska' variety and the worst had 'Koloseum F1' variety. According to these results, it is recommended to continue in research.
Production of pigments by yeasts
Gonová, Dominika ; Hlaváček, Viliam (referee) ; Němcová, Andrea (advisor)
Carotenoids are naturally occurring pigments synthesized by yeast, bacteria, filamentous fungi and plants. In recent years, the interest in the study of these pigments and their microbiological production is increasing mainly due to significant biological effects attributed to carotenoids. This work is conceived as comparative study of six carotenogenic yeasts: two strains of species Rhodotorula glutinis, Rhodotorula mucilaginosa, Sporobolomyces roseus, Sporobolomyces metaroseus a Sporobolomyces pararoseus. Their cultivation was carried out in various media where the oxidative stress was applied in the form of hydrogen peroxide and also waste material – egg pasta – was used as a nutrition source. All studied strains were able to use waste substrate as a source of nutrients, in case of the genus Sporobolomyces increasing production of metabolites was observed. Under the oxidative stress, the majority of the studied yeast showed overproduction of carotenoids and accompanying lipid substances. Sporobolomyces roseus CCY 19-6-4 was characterized by the highest production of carotenoids (1923.78 µg/g -carotene) at the egg pasta media, but on the other hand, it showed a significant decline in biomass. As potentially the best producer of biomass (9.85 g/l) and carotenoids (780.24 µg/g of -carotene), the yeast Rhodotorula glutinis CCY 20-2-26 was observed. Pulcherrimin, synthesized mainly by yeast but also by some spore-forming bacteria, also belongs among natural pigments. Recently, its antagonistic effect that was shown against several microorganisms has been intensively studied, as it seems to be very relevant in regard to biological control. The second part of the work deals with the regulation of pulcherrimin production and its antimicrobial activity. As the pigment-producing yeast strains were used Metschnikowia pulcherrima 145, Metschnikowia pulcherrima 147, Mestchnikowia pulcherrima 149, Metschnikowia andauensis 129, which were cultured on various media containing different concentrations of metal ions and hydrogen peroxide as exogenous stress. In the study of pulcherrimin antagonistic effect, gram-positive bacteria Lactobacillus sakei, gram-negative bacteria Escherichia coli, yeast Candida glabrata and filamentous fungi Phanrochaete chrysosporium were used as tested microorganisms. All studied yeasts were able to produce pulcherrimin, and therefore to show antagonist effect, only in media supplemented with iron, while the color intensity was proportional to the concentration of iron. Antimicrobial activity of pulcherrimin was not observed only against bacteria Escherichia coli.
Use of selected fluorescence techniques to study of yeasts and yeast metabolites
Mikheichyk, Nadzeya ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
The scope of thesis was the optimization of methods for the study of yeast and their metabolites using flow cytometry and fluorescence microscopy. Red yeasts are characterized by overproduction of carotenoids and lipids, which are used in food, pharmaceutical and feed industries. Currently, intensive research is being carried on to find appropriate microbiological alternatives for synthesis of these substances. Present thesis is focused on selected yeast genera: Rhodotorula, Sporobolomyces, Cystofilobasidium and strain Phaffia rhodozyma. Yeasts were cultivated on different nutrient media, in which glucose was used as a nutritional source, and also on glycerol and whey as waste material. In two strains - Cystofilobasidium macerans and Rhodotorula mucilaginosa growth characteristics were determined on a synthetic glucose production medium. All studied strains were able to use waste substrates as a source of nutrients. Some of the strains displayed increased production of carotenoids, and, additionally, in some cases also relatively high production of lipids. In classical cultivation in lipid and glucose medium supplemented with vitamins the best production characteristics displayed Rhodotorula glutinisstrain. In glycerol medium the highest amount of carotenoids and lipidic substances produced Sporobolomyces shibatanus strain. Strain Sporobolomyces roseus showed the best production characteristics on whey as the main source of carbon. The results show use of whey and glycerol seems like appropriate option for potential carbon source to cultivate carotenogenic yeasts and production of carotenoids and selected lipidic substances as products with higher added value. Further optimization of nutrient medium on the given substrates is needed for higher production of selected metabolites. Fluorescence microscopy and flow cytometry have proved to be suitable options for determination of the observed metabolites in the cells, their amount and viability.
A comparison of metabolic activity and use of microalgae and pigment-formed yeasts
Szotkowski, Martin ; Kočí, Radka (referee) ; Márová, Ivana (advisor)
Carotenoids are natural pigments occurring in plants and many microorganisms, such as algae, yeast and bacteria. They represent the most common group of antioxidants with significant biological effect. Lipids are an essential component of all living organisms. They are the source and the reservoir of energy for organisms, which can also be used in the petrochemical industry for the production of biofuels. This thesis deals with the production properties of carotenoids and lipids by selected strains of yeasts, algae, and canobacteria, in order to apply the acquired knowledge and find cheap suitable alternatives for microbial biotechnological production of these metabolites using waste substrates. Carotenoids, coenzyme Q, and ergosterol in cells were determined by liquid chromatography. The lipid content and fatty acid profile was analyzed by gas chromatography. Cell morphology and localization of selected metabolites were analyzed by fluorescence lifetime imaging microscopy. In this work yeast genera Sporobolomyces, Cystofilobasidium and Rhodotorula were used. As the representatives of the algae and cyanobacteria strains of Desmodesmus, Cyanothece, Chlamydomonas, Synechoccocus and Chlorella strains were studied. In the overall comparison, the yeast strains were more productive than algae and cyanobacteria. The highest carotenoid production was found in S. pararoseus, C. capitatum and R. mucilaginosa cells, while the highest lipid yield was observed in strains of C. infirmominiatum and S. metaroseus.

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