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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
251

Produkce lipolytických enzymů kvasinkami / Production of lipolytic enzymes by yeasts

Bradáčová, Kristína January 2018 (has links)
This diploma thesis is focused on controlled production of lipolytic enzymes, bioactive substances and lipids by carotenogenic yeasts. Theoretical part deals with characterization of lipolytic enzymes, carotenoids, lipids and their properties, possibility of production and application. In experimental part the enzymes, carotenoids and lipids were produced by red yeasts Rhodotorula mucilaginosa, Cystofilobasidium macerans and Sporidiobolus salmonicolor by submerged cultivation in mineral medium with different additions: glucose, glycerol, fat, fat with glucose, fat with polysorbate 80, fat with glycerol, fat with polyethylene glycol, fat with higher and lower addition of palmitic acid, enzymatic fat hydrolysate, acidic hydrolysate a basic hydrolysate. The activity of extracellular lipase was monitored in medium after 96-hour cultivation. Concentration of -carotene, total carotenoids, ergosterol and ubiquinone was determined by HPLC, concentration of fatty acids and amount of fat by GC. Production had differed depending on used yeasts and substrate. As the best producer of carotenoids Cystofilobasidium macerans was found, ergosterol was highly produced by Sporidiobolus salmonicolor. The production of ubiquinone was almost equivalent in all yeasts and lipolytic activity was the highest in Sporidiobolus salmonicolor. The patricular medium sample with high lipolytic activity was further separated and analysed by ultrafiltration and PAGE-SDS electrophoresis. This diploma thesis was done within the international project ,,LipoFungi“.
252

Produkce beta-glukanů vybranými druhy kvasinek, řas a sinic / Production of beta-glucans by some yeasts and algae

Veselá, Markéta January 2018 (has links)
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.
253

Valorizace odpadního živočišného tuku pomocí karotenogenních kvasinek / Valorization of waste animal fat by carotenognic yeasts

Chrástová, Nikola January 2019 (has links)
This diploma thesis deals with valorization of waste animal fat using carotenogenic yeast and conversion to biomass enriched with valuable substances. These microorganisms have the ability to utilize various waste substrates and convert them into interesting products such as carotenoids, lipids, ergosterol and ubiquinone. Four strains of yeast (Rhodotorula glutinis, Cystofilobasidium macerans, Rhodotorula mucilaginosa, Sporidiobolus pararoseus) were used. The theoretical part is focused on characterization of yeasts, enzymes and lipases, produced metabolites, yeast and description of analytical methods. In the experimental part, cultures were performed at four C/N ratios on media with different carbon sources, which were glucose, glycerol, fat, fat with added emulsifier, enzymatically hydrolyzed fat and fat with enzyme addition. Biomass was determined gravimetrically for all samples. Carotenoids, ergosterol and ubiquinone were analyzed on an HPLC/PDA equipment. The intracellular lipid content was determined by GC/FID. The production of these substances was different in individual strains depending on the carbon source and the C/N ratio. Rhodotorula glutinis is the most suitable for producing biomass and carotenoids. The highest amounts of ergosterol and ubiquinone were produced by Cystofilobasidium macerans. Sporidiobolus pararoseus had the largest lipid content in biomass. This diploma thesis was elaborated within the international project "LipoFungi".
254

Studium produkce beta-glukanů a dalších polysacharidů pomocí kvasinek a mikrořas / PRODUCTION OF BETA-GLUCANS AND OTHER POLYSACCHARIDES BY YEAST AND MICROALGAE

Byrtusová, Dana January 2020 (has links)
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.
255

Využití metody LC/MS k analýze vybraných přírodních fyziologicky aktivních látek / Use of LC/MS technique to analysis of some physiologically active natural compounds

Trčková, Marie January 2008 (has links)
Presented work is focused on application of combined instrumental method RP-HPLC/ESI-MS in analysis of several groups of natural compounds with positive physiological activities. Especially some antioxidants were studied in commonly and abundantly consumed food. Moreover some other substances than standard compounds were observed in complex dies. In conclusion the HPLC/ESI-MS method is comparatively advantageous in phenolic analysis, while another type of ionisation would be used in case of carotenoid compound.
256

Sledování metabolických změn karotenogenních kvasinek v závislosti na podmínkách kultivace / Study of metabolic changes in carotenogenic yeasts cultivated under different conditions

Starečková, Terezie January 2008 (has links)
The aim of this diploma thesis realized as a comparative study was the study of regulation of carotenoid and ergosterol production in several carotenogenic yeast strains. Yeasts were exposed to exogenous stress factors. Salt stress and oxidative stress (hydrogen peroxide) were reached by addition of NaCl and hydrogen peroxide into production media. Complex changes on metabolome (e.g. pigment and ergosterol production, RP-HPLC), proteome and genome were followed. Proteome changes were analyzed by PAGE-SDS and 2D electrophoresis. To isolation and analysis of chromosome DNA pulsed field gel electrophoresis (PFGE) was used. Six yeast strains were enrolled into the comparative study; three strains of the genus Rhodotorula and three strains of the genus Sporobolomyces. While yeasts Rhodotorula sp. were characterized by enhanced biomass as well as carotenoid production in normal and stress conditions, production of biomass by Sporobolomyces sp. was substantially lower. Carotenoid production in Sporobolomyces sp. was higher than in Rhodotorula sp.; the highest increase of was beta-carotene production was observed in Sporobolomyces salmonicolor cells stressed by salt (4x higher than in control) or peroxide (5x higher). Proteins were isolated from yeast cells by combination of mechanical and chemical disruption by glass beads and NaOh or SDS. Better yields were obtained by NaOH. Two staining methods were tested in PAGE-SDS protein analysis. Coomassie Brilliant Blue staining exhibited lower sensitivity, silver staining led to better visualisation of minor protein fractions too. 1D protein profiles was difficult to evaluate, therefore, 2D electrophoresis of selected strains (R.glutinis, R.rubra) was done. In yeast genome analysis by PFGE at minimum 7 DNA fractions were observed. These results probably are not final, further study will be needed for detailed characterization of red yeast genome.
257

Mikrobiální produkce karotenoidních pigmentů s využitím odpadních substrátů / Microbial production of carotenoid pigments using waste substrates

Němcová, Andrea January 2010 (has links)
Carotenoids are naturally occurring pigments produced by bacteria, yeasts, filamentous fungi and plants. They exhibit significant biological effects and are widely used in the food industry, pharmacy and cosmetics. The aim of this diploma thesis proposed as a comparative study was regulation of carotenoid and ergosterol production in red yeasts using several waste substrates as whey, corn germs, wheat, apple fiber and pasta. To selected production media extracellular hydrolytic enzymes degrading polysaccharide were added. These enzymes were obtained from the cultivation media of four fungal strains. In this study three carotenogenic yeast strains were used: Rhodotorula glutinis, Sporobolomyces roseus and Cystofilobasidium capitatum. All strains were cultivated simultaneously and changes in biomass and carotenoid production in different production media were monitored and compared. As the best waste substrate apple fiber was utilized, particularly in Rhodotorula glutinis, which exhibited mainly biomass production increase. In Sporobolomyces roseus increased production of biomass and carotenoids have been reported in media with hydrolyzed fiber and pasta as well. Beta-carotene production in this strain reached 4776,38 mg/g of dry weight. The strain Cystofilobasidium capitatum exhibited in waste media a decerase of biomass production accompanied with increased production of carotenoids, especially in wheat mush and pasta medium hydrolyzed by enzyme preparative from Aureobasidium pullulan. It can be concluded that hydrolyzed waste substrates are very hopeful as cheap nutrient sources for yeast strains producing carotenoids and ergosterol. Nevertheless, further study of substrate processing for individual strains is needed.
258

Využití odpadních surovin k produkci obohacené kvasinkové biomasy / Use of Waste Substrates to Production of Enriched Yeast Biomass

Starečková, Terezie January 2011 (has links)
Yeasts are like other organisms constantly exposed to environmental influences. Their survival depends on the skills to adapt to environmental changes, including the ability to use various alternative sources of nutrients. In presented PhD thesis carotenogenic yeast belonging to the genera Rhodotorula, Sporobolomyces and Cystofilobasidium were tested for ability to use of selected waste substrates, and also subjected to several types of exogenous stress effects and mutations in order to increase the production of microbial biomass enriched with specific metabolites. As alternative nutrient sources derived from waste substrates from agricultural and farm production apple peel, pulp, corn germ and more were tested. Yeasts were also exposed to osmotic, oxidative and combined stress (benefits of various concentrations of NaCl and H2O2 to the culture media), followed by metal ions of selenium and chromium in concentrations of 0.01 mM, 0.1 mM and 1 mM. The effect of mutagen methanesulfonic acid ethyl ester was tested too. In all experiments the adaptivity of cells, morphological changes, color pigments produced by the media while some important fungal metabolites production and changes in chromosomal DNA fragmentation were analyzed. In order to evaluate potential changes in the yeast genome after treatment with mutagen and stress factors methods for isolation of intact chromosomal DNA and DNA analysis by pulsed field gel electrophoresis was optimized. The amount of produced metabolites was mainly analyzed by RP-HPLC with UV/VIS and MS detection. The work has been shown that most strains are able to use waste substrates and produced selected target metabolites. Biomass, for example, in R. aurantiaca on apple fiber was about 7 g/l and in C. capitatum cultivated on modified whey reached to 9 g/l. Amount of produced carotenoids by R. aurantiaca cultivated on wheat germ and maize after enzymatic hydrolysis by F. solani was 1.01 mg/g and S. roseus on pasta 4.3 mg/g. The values of ergosterol synthesis in R. aurantiaca are on the apple shells around 4.8 mg/g, in S. roseus on pasta with the enzymatic hydrolysis of P. chrysosporium 8.9 mg/g. The best substrate for biomass production and induction of carotenoids are waste substartes containing a mixture of simple and complex carbohydrates enriched with the addition of nitrogen compounds. Potential cytotoxic effect of stress factors of low concentrations was demonstrated. Red yeast genome was able to distribute by optimized PFGE, the karyotype of tested yeasts contain 11 or more chromosomes with visible differences between yeast species and genera. During exchange internship the ability of recombinant yeast S. cerevisiae to convert xylose to xylitol, which would be achieved by increasing the production of bioethanol as alternative fuel sources was studied. It turned out that both ligninocellulose materials to bioethanol production, as well as various waste substrates for microbial synthesis of carotenoids would reduce costs for industrial production of yeast metabolites, as well as to reduce the negative burden on the environment.
259

Produkce vybraných kvasinkových metabolitů využitelných do potravinových doplňků / Production of Selected Yeast Metabolites Applicable to Food Supplements

Němcová, Andrea January 2014 (has links)
Carotenoids are naturally occurring pigments of plants also produced in many bacteria, and fungi. They represent one of the widest group of natural antioxidants with significant biological effects and numerous of industrial applications. There is an increased interest in carotenoids as natural antioxidants for their ability to reduce chronic diseases, various pathological stages and aging. The area of their application concerns mainly food industry; however, they are used in chemical, pharmaceutical, and cosmetics industry as well. One possibility is study of potential of red yeasts that are able to convert various substrates into carotenoid pigments. In presented thesis carotenogenic yeast belonging to the genus Rhodotorula, Sporobolomyces and Cystofilobasidium were tested for ability to use of selected waste substrates and also random mutagenesis in order to increase the production of biomass and specific metabolites – carotenoids and other lipid-soluble substances. As alternative nutrient sources derived from waste substrates from agricultural and food production (rapeseed substrate, rice, wheat, apple fiber, pasta and lignocellusic materials) were tested. To selected production media extracellular hydrolytic enzymes or commercial enzymes degrading polysaccharide were added. All tested red yeast strains were able to utilize these substrates as the only carbon source and simultaneous produce carotenoid enriched biomass. In this work, characterization of carotenogenic yeast using molecular techniques was studied. For this usage, interspecific variables of strongly conserved sequences of genomic DNA, especially rDNA D1/D2 large ribosomal subunit and ITS1 and 5,8-ITS2 rDNA regions were amplified. These sequences were subjected analysed by DGGE method to compare differences of carotenogenic yeasts. Isolation procedure of the intact DNA were optimized for caryotypic yeast characterization by pulsed field gel electrophoresis (PFGE). The karyotype of tested yeasts contain visible differences between yeast species and genera.
260

Srovnání metabolické aktivity a potenciálního využití mikrořas a pigmentotvorných kvasinek / A comparison of metabolic activity and use of microalgae and pigment-formed yeasts

Szotkowski, Martin January 2016 (has links)
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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