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Production of Selected Yeast Metabolites Applicable to Food Supplements
Němcová, Andrea ; Čertík, Milan (referee) ; Vávrová, Milada (referee) ; Márová, Ivana (advisor)
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.
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Analysis of biologically active substances in some cereal products
Valentová, Radka ; Starečková, Terezie (referee) ; Márová, Ivana (advisor)
Presented bachelor thesis is focused on study of biologically active substances in cereal products. In theoretical part over view of cereal active substances, predominantly phenolic compounds were introduced. In practical part 15 kinds of cereal products were analyzed. In these materials some group parameters - total phenolics, total flavonoids and total antioxidant activity were measured by spectrophotometry. RP-HPLC/UV-VIS method was performed for analysis of selected individual flavonids. The highest content of phenolic compounds was measured in cereals containing fruits (raspberries, blueberries, tropical and red fruit), cacao, crusty fruits (hazel nuts, sunflower seeds) and buckwheat. All cereal products contain catechine, epicatechine, catechin gallate, epicatechin gallate, chlorogenic and ferulic acid. As a part of bachelor thesis simple sensory analysis was performed and consumer questionnaires were evaluated.
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Development of organic UV filtres based on natural extracts
Káčeríková, Martina ; Kovalčík, Adriána (referee) ; Márová, Ivana (advisor)
This diploma thesis is focused on the development of organic UV filters. Organic UV filters were extracted from natural resources and encapsulated into nanomaterial-like delivery systems such as liposomes and nanofibres. SPF of particular extracts and carriers with encapsulated extracts were measured. All of the prepared extracts as well as carriers were characterised for their content of natural substances like phenolic compounds and their antioxidant acitvity, stability, cytotoxicity, micriobial acitivity and their safety were studied too. All of the prepared materials were evaluated as suitable for use in comestic industry. However, in a future, it would be appropriate to add to the study other experimental methods to increase the active substances and at the same time increase the SPF protection factor.
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Advanced materials for organic electronics and bioelectronics
Šudomová, Lucie ; Márová, Ivana (referee) ; Weiter, Martin (advisor)
This bachelor thesis focuses on the characterization of organic materials with semiconductor properties in terms of their potential use in bioelectornic applications. The theoretical part is summarizing the basic characteristics of organic materials for organic electronics and bioelectronic. There are mentioned basic structures and general properties of relevant substances. This part of the thesis also describes the basic principles of devices for bioelectronic applications and its use. Practical part includes preparation of thin films of two types substances: on the basis of low-molecular organic substances (6,13-bis(triisopropylsilylethynyl) pentacene and diketopyrrolopyrrole) and another based on polymers (Poly (3-hexylthiophene-2,5-diyl) and Poly (3,4-ethylenedioxythiophene): poly (styrene sulfonic acid) and). The first part of the experiment is focused on the characterization of the properties of used substances. The second part examines microbial biocompatibility
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Biotechnological valorization of some food wastes by yeasts
Majdloch, Robert ; Bendová, Agáta (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with biotechnological valorisation of waste substrates, namely waste fat, whey and feathers using carotenogenic yeast. Waste substrates serve as alternative source of nutrients for subsequent cultivation, thanks to this, their utilization and subsequent production of carotenoids, ergosterol, coenzyme Q and lipids occurs. The theoretical part contains the information of selected strains of carotenogenic yeast, such as physiological and growth properties. Their metabolic processes are described together with produced substances. The analytical methods for the determination of substances are described as well. The experimental part focuses on the solution of flask and bioreactor cultivations of four selected strains (Rhodotorula kratochvilovae, Rhodotorula mucilaginosa, Cystofilobasidium macerans a Sporidiobolus pararoseus) on glucose, glycerol and waste substrate at different C/N ratios (13, 25, 50 and 100). Furthermore, individual procedures of waste substrate processing, procedures solving isolation and determination of selected carotenoid substances, which were analysed by HPLC/DAD. Lipid content and their percentage amount were determined by GC/FID. The results of flask and bioreactor cultivations show that the strains have different production at individual C/N ratios. Rhodotorula mucilaginosa strain was selected as the best producer of carotenoids and ergosterol. The highest increases in biomass were achieved by Rhodotorula kratochvilovae strain. Lipid production was the best in the Sporidiobolus pararoseus strain.
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Analysis of nicotin content in some products
Pražáková, Jana ; Kočí, Radka (referee) ; Márová, Ivana (advisor)
This diploma thesis deals with the determination of nicotine in different products. The theoretical part summarizes review on nicotine, smoking and opportunities how to quit. In the practical part a method for the determination of nicotine by HPLC / PDA was optimized. As the most suitable stationary phase was selected a Kinetex 5u C18 100A 150 x 4.6 mm column, as the optimal mobile phase was chosen a pure methanol with a flow rate of 1 ml min-1 and a temperature of 25 °C. For the analysis of nicotine were chosen: 18 kinds of cartridges for electronic cigarettes, two kinds of nicotine gum, nicotine spray, nicotine pastilles, nicotine orodispersible film and ten species of classic cigarettes. For each type of product the most appropriate method for extracting nicotine and its subsequent analysis by HPLC / PDA was found. For tobacco 24 hour extraction in methanol and 10s ultrasound was selected. The nicotine spray and electronic cigarette refills without flavours were only diluted with methanol. Flavoured refills were first diluted by sodium hydroxide and then with methanol. For chewing gums, pastilles and nicotine film extraction with 5% sodium hydroxide was chosen. In this study also new experimental nicotine product was designed. Nicotine has been encapsulated in alginate-starch material to form small gel particles. As the most suitable medium for storage the water medium was determined.
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Preparation of bioactive wound dressings and testing their interaction with human cells
Bendová, Agáta ; Márová, Ivana (referee) ; Skoumalová, Petra (advisor)
The thesis was focused on the preparation and optimization of the preparation of wound dressing from materials with bioactive ingredients. In this work were prepared nanofiber dressings based on polyhydroxybutyrate and non-fibrous dressings from alginate and chitosan. Nanofibers were prepared by electrospinning and forcespinning methods. The bioactive components, which were used to functionalize the prepared dressings, were plant extracts, clotrimazole, ampicillin, lysozyme, and proteolytic enzymes. The theoretical part is focused on the description of the use of nanofibrous and non-fibrous materials in medicine, characterization of materials for the production of wound dressings and bioactive components. Furthermore, this section describes the methods used to prepare and characterize wound dressings. In the practical part were prepared aqueous and oil extracts from selected plants. Extracts were characterized for polyphenols content and antioxidant activity. PHB-based nanofibers were prepared using electrospinning and forcepinning methods. Nanofibers were enriched with selected plant oil extracts and clotrimazol. Modified nanofibres were detemined for antioxidant activity, short-term and long-term stability. Non-fibrous wound dressings were prepared from alginate and chitosan. These dressings were functionalized by the addition of selected aqueous extracts, ampicillin, lysozyme, papain, bromelain, and collagenase. Non-fibrous wound dressings were determined for antioxidant activity, short-term stability and proteolytic activity. The prepared wound dressings were tested for their antimicrobial effects on cultures of Micrococcus luteus, Serratia marcescens, Staphylococcus epidermidis and Escherichia coli. In conclusion, successfully prepared bioactive wound dressings with antioxidant and antimicrobial agents were tested for safety on human cells. The determination was performed using the MTT cytotoxicity test on human keratinocytes.
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Study of polyhydroxybutyrate production in bacteria
Melušová, Soňa ; Babák, Libor (referee) ; Márová, Ivana (advisor)
Presented work is focused on study of polyhydroxybutyrate production in bacteria. In theoretical part short characterization of PHB was given and the most common representative of wide group of polyhydroxyalkanoates (PHA) were described. Then, production of PHB and copolymer P(HB-co-HV) in selected bacterial strains was experimentally proven. First, PHB production in Bacillus megaterium using synthetic medium was studied. The PHB content in cells was increased during cultivation under limiting conditions, despite low growth. Addition of ethanol into production media resulted in increased PHB synthesis as well as biomass production (21 % PHB of 1,8 g/l biomass). Further, BM medium containing 8 g/l glucose was tested. PHB production was more than 1 g/l at significant growth increase when compared with synthetic medium. The bacteria B.megaterium showed, except glucose, ability to utilize maltose and xylose. Another cultivations were tested with bacterial strain Azotobacter vinelandii, which is capable of copolymer P(HB-co-HV) synthesis. Maximal growth and copolymer content was reached on Burk's medium with 30 g/l of glucose. Addition of peroxide to growth medium influenced P(HB-co-HV) synthesis to 46 % of 2,6 g/l biomass. Bacteria A.vinelandii showed the best growth on maltose, even compared with glucose (54 % copolymer of biomass content). Finally, PHB production on industrial waste product – whey was monitored. Using Plackett-Burman design for statistical media optimization, the whey content was modified. B.megaterium grown on adjusted whey reached 0,5 g/l PHB, 32 % of cell's content.
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Use of carotenogenic yeasts to production of lipid soluble metabolites
Mariničová, Veronika ; Hlaváček, Viliam (referee) ; Márová, Ivana (advisor)
Carotenoids are fat-soluble chemical compounds that occur as natural pigments in many plants and protect them from sunlight. Lipids are also essential lipophilic substances and they are part of biomembranes. Their main function is primarily to serve as a power supply for the cell, protective function and thermal protection against adverse environmental influences. This bachelor thesis deals with cultivation of selected carotenoid yeast genes, subsequent isolation of carotenoids and other lipid substances, which can be used as a source of potentially beneficial substances for the pharmaceutical or cosmetic industry. The theoretical part deals with the description of carotenoid yeasts, chemical composition and biosynthesis of the metabolites produced, and description of the methods used for their determination. The experimental part is focused mainly on the production of lipid substances by various strains of yeasts using cheap waste substrates and the application of exogenous stress (nutritional stress) to the biotechnological overproduction of selected metabolites using the modification of the production medium. The content of carotenoids, ergosterol and coenzyme Q was analyzed by high performance liquid chromatography with a PDA detector. The lipids accumulated in yeast cells were determined by gas chromatograph with a FID detector. In this work the strains of Sporobolomyces pararoseus, Sporobolomyces metaroseus, Rhodotorula glutinis and Cystofilobasidium infirmominiatum were studied. As waste substrates and carbon sources were used glycerol, which is produced as a waste product in the production of biofuels and whey as an unusable product in dairy technology. The best production on waste substrates was observed in the strains Rhodotorula glutinis and Cystofilobasidium infirmominiatum.
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Encapsulation of lactic acid bacteria
Vrtná, Monika ; Lichnová, Andrea (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on encapsulation of two strains of probiotic bacteria. Lactic acid bacteria were encapsulated into several types of materials, mostly polysaccharides. The theoretical part describes the techniques of encapsulation applicable in the food industry. During the experimental part alginate and chitosan microparticles were prepared. These particles exhibited different sizes and some of them were modified by starch and carboxymethyl cellulose. Particles were used for encapsulation of two strains - Bifidobacterium breve and Lactobacillus acidophilus. Using flow cytometry cell viability was measured after 24-hours cultivation of bacteria. Particles were observed immediately after encapsulation by optical microscopy and then long-term stability in model foods was evaluated after two days, a week and after four weeks of incubation. Using the Bürker chamber the alived and death bacteria were counted inside and outside the capsule. The stability and viability of the cells were studied also in the artificial intestinal, stomach and bile juices. As the best material for encapsulation of lactic acid bacteria 2% alginate modified by carboxymethyl cellulose was found. The highest viability of bacteria was observed in milk as the real model food. Prepared particles are suitable for use in the food industry.
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