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The Study of Biopolymers Stability Using Light Scattering Techniques
Kratochvíl, Zdeněk ; Sedláček, Petr (referee) ; Kalina, Michal (advisor)
The stability of chosen biopolymers (or simple carbohydrates and amino acids) was in-vestigated using light scattering methods. Samples were prepared by dissolving the sub-stance in deionised water or in diluted acetic acid. Firstly, the effect of increasing concen-tration on zeta potential was observed and the optimal concentration for the next measure-ments was determined. Afterwards, the stability and the molecular weight of used sub-stances were studied during long-time storage in different time intervals. It was found out that chitosan, CMC, hyaluronate and sodium alginate were subjected to degradation whereas increase of the molecular weight and the zeta potential was observed in case of BSA. In the end, the samples were exposed to several different external effects, namely the influence of different temperatures, UV radiation and increasing ionic strength. The results showed that rather higher temperature has a significant impact on biopolymers stability. However, used biopolymers were hardly affected by UV radiation except BSA whose molecular weight increased considerably. Decrease of the zeta potential absolute values and the molecular size usually occurred with increasing ionic strength. The change of molecular weight was not detected.
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Pectin - its properties and industrial applications
Odstrčilová, Eva ; Vránová, Dana (referee) ; Omelková, Jiřina (advisor)
This thesis deals with pectins substances in food processing and pharmaceutical industry. Pectin is very using component in food processing products, mainly due to jelly and thickening ability. The thesis is dedicated plant cell wall, where is located pectin including other material component of plant cell wall. Further it is described structure of pectin, including his production and use in industry. The last part of the thesis is dedicated enzymatic degradation of plants origin materials. Pectin is very using, but its structure and biosynthesis is still not fully explored.
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Testing of biological effect of glucans on cell lines in vitro
Šimková, Eva ; Holub, Jiří (referee) ; Němcová, Andrea (advisor)
The aim of this bachelor thesis is isolation and testing of -glucans from selected strains of yeast. In the theoretical part, characterisation of -glucans, microbial production of -glucans by yeast, determination of polysaccharides, exopolysaccharides and in vitro testing are described. Yeast have a cell wall made up of -glucans and -glucans are known for their healing properties. In the experimental part of this work deals with characterization of selected biomass yeasts in different forms and comparison of their effects and the amount of -glucans in each form. Stains of Metschnikowia pulcherrima, Cystofilobasidium infirmominiatum and Rhodotorula kratochvilovae have been selected for this thesis. Subsequently, the thesis deals with the isolation and testing of isolated -glucans from a selected lyophilised strain of yeast Rhodotorula kratochvilovae. The selected strain was isolated in 2 ways. The first method of isolation that was more friendly to conformation of -glucans due to the effect of ultrasonic homogenization of cells. The second method of isolation was less friendly to -glucans, using acid and base to homogenise them. Analyses of both extraction methods confirmed the presence of isolated -glucans, however it was found that the recovery of both methods was relatively low and requires further optimisation of the procedure. Overall, the better extraction procedure was the second method. A sample of this extract was further tested on the HaCaT cell line. The results of the pilot tests confirmed the cytotoxicity of the extract obtained by us.
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Determination of honey authenticity and adulteration by anion exchange chromatography
Ždiniaková, Tereza ; Diviš, Pavel (referee) ; Vespalcová, Milena (advisor)
Cieľom tejto diplomovej práce je stanoviť kvalitu a zloženie medu, taktiež stanoviť jeho botanický pôvod na základe profilu sacharidov v mede. Med je prírodný produkt vysokej kvality a vďaka značnej spotrebe a nemalej trhovej hodnote je tiež terčom na falšovanie. S cieľom identifikovať podvody a cudzorodé látky, pochádzajúce z cukrových sirupov, boli analyzované oligosacharidy a polysacharidy na báze maltodextrínov. Teoretická časť popisuje chemické zloženie medu a hlavné princípy aplikovanej inštrumentálnej techniky. Poskytuje literárny prehľad existujúcich analytických metód na stanovenie sacharidov prítomných v mede a na odhalenie jeho falšovania. Boli definované hlavné body falšovania a autenticity, vrátane legislatívnych aspektov a opisu bežných druhov falšovania. Experimentálna časť obsahuje postupy, ktoré vedú k vývoju a optimalizácii chromatografických podmienok a parametrov elektrochemického detektora na stanovenie sacharidov a maltodextrínov (oligosacharidov a polysacharidov) vo vzorkách medu. Použitá analytická technika bola vysoko účinná aniónovo-výmenná chromatografia (HPAEC) spojená s pulzným amperometrickým detektorom (PAD). Vyvinutá a optimalizovaná chromatografická metóda bola taktiež validovaná z hľadiska linearity, dynamického rozsahu, analytických limitov, presnosti a správnosti. Na záver bola táto vypracovaná metóda úspešne zhodnotená analýzou autentických a falšovaných vzoriek medu rôzneho botanického pôvodu pochádzajúcich z členských štátov EÚ.
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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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Metody ošetření čerstvého ovoce a zeleniny na bázi ochranných povrchových aplikací
Bůšek, Filip
This bachelor's thesis elaborates an overview of protective surface applications on fresh fruits and vegetables based on biocompatible polymers, which can be abbreviated as edible coatings, which can be made of polysaccharides, proteins or lipids, or a combination of several materials, referred to as composite coatings. It also deals with the method of their application to the surface of food, where the basic ones include dipping, spraying and brushing. The properties of edible coatings can be improved by incorporating active substances such as antimicrobial agents, texture improvers or nutraceuticals. The next part of the work summarizes the positives, but also the shortcomings of edible coatings and some materials applied to individual types of food. The final part deals with current research and perspectives in the field of edible coatings.
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Cross-correlation of mechanical properties of hydrogels on micro/macro-scale studied by atomic force microscopy and oscillation rheometry
Kuzník, Pavel ; Szabová, Jana (referee) ; Smilek, Jiří (advisor)
This bachelor thesis focuses on measurement of mechanical properties of hydrogels on local and macroscopic level by atomic force microscopy (AFM) and oscillation rheometry. Both techniques allows measurement of hydrogel in hydrated state which provides native state of measured samples and prevents them from inserting artefacts into measurements made by AFM, which could negatively change measured values. AFM has more measuring modes, but for measurement in this bachelor thesis was used tapping mode called Contact mode force mapping. The largest part of this work is concentrated on measurement of agarose hydrogel, which pertains to category of physical hydrogels, concretely concentration line and time dependency (syneresis of hydrogel) were measured by both techniques. Suitability of AFM for measuring of mechanical properties of hydrogels was tested on other hydrogel samples with different type of crosslinking. Hydrogel based on sodium alginate crosslinked by calcium ionts (Ca2+) was tested. Furthermore were measured two chemical gels including polyethylenglycol (PEG) hydrogel and organogel of ethylene propylene-diene monomer (EPDM). Measurement of PEG hydrogel included time dependency due to its swelling and absorption behaviour, which led into dissolving of PEG hydrogel. EPDM organogel is not dissolving in water, so it was measured as a standard for AFM measurements. In addition to Young’s modulus as a base parameter for measurement of hydrogels in swollen state, was adhesion and work of adhesion tested in case of EPDM gels.
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The influence of polysaccharide contamination on molecular-biology analysis
Žylková, Kateřina ; Strečanská, Paulína (referee) ; Fialová, Lenka (advisor)
The presence of polysaccharides in DNA isolation and its subsequent analysis often leads to undesirable effects. Polysaccharides together with other metabolites (phenolics, proteins) can act as inhibitors of PCR. In this work, the effect of polysaccharide contamination on the analyzed DNA was investigated. In the experimental part, DNA samples were isolated from two exotic fruits (mango, banana), from which the concentration of polysaccharides was then determined. The analysis showed that by adding CaCl2, the polysaccharide content of the samples was significantly lower. After checking the amplification of the DNA samples with added CaCl2, it was found that CaCl2 itself inhibited PCR and therefore had to be removed from the samples. After purification, the amplification of the DNA was reverified and it was found that the DNA with CaCl2 after purification gave the best results. These results were further verified by agarose gel electrophoresis, which confirmed that a reduction in the polysaccharide content of the samples helped DNA amplification. It was also observed that it depends on the type of polysaccharides present in the source plant material. Banana DNA showed better amplification results than mango DNA. This is due to the different chemical composition of these fruits. Banana, unlike mango, does not contain polysaccharides that would significantly contaminate the isolated DNA.
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Optimization of methods for the isolation and analysis of beta-glucans produced by carotenogenic yeasts
Šimková, Eva ; Márová, Ivana (referee) ; Szotkowski, Martin (advisor)
The aim of this thesis was to optimize the methods of isolation and analysis of -glucan polysaccharides produced by carotenogenic yeasts. As part of the experiment, the yeast Rhodotorula toruloides, which was cultivated in laboratory bioreactors, was selected as the production strain. Theoretical part describes the subject of carotenogenic yeasts and the metabolites they produce. The main metabolite that this work deals with is the polysaccharide -glucan. -glucans are polysaccharides that form the cell wall in the yeast cell. They are known for their immunostimulating effects, antioxidant effects, promote wound healing and help lower cholesterol and blood glucose levels. The experimental part of the work deals with the cultivation of yeast biomass and its characterization. Furthermore, optimization of the enzymatic determination of -glucans using a commercial enzymatic kit and isolation of -glucans from yeast biomass. As part of the experiment, yeast biomass extraction methods were also further developed, enabling the separation and analysis of -glucans, lipids, lipidic substances and proteins from a small sample of yeast biomass in one extraction procedure.
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Characterization of extracellular and intracellular organic matter produced by phytoplankton in relation to water treatment
Zezulová, Tereza ; Pivokonský, Martin (advisor) ; Janda, Václav (referee)
This study investigated characteristics of algal organic matter (AOM) derived from four species (cyanobacteria Microcystis aeruginosa and Merismopedia tenuissima, diatom Fragilaria crotonensis and green alga Chlamydomonas geitleri) dominating phytoplanktonic populations in the reservoirs supplying drinking water treatment plants - the water reservoirs Švihov (the Želivka water treatment plant) and Josefův Důl (the Jizerské Mountains), Czech Republic. The four mentioned microorganisms were cultivated under laboratory conditions and the algal growth was quantified by a number of cells, chrorophyll-a and optical density. Production of AOM was evaluated by dissolved organic carbon concentration measurements, by specific UV absorbance, the amount of peptide/protein and non-peptide (carbohydrate) contents, water affinity and molecular weight (MW). AOM of all considered microorganisms are formed predominantly by hydrophilic substances with low values of specific UV absorbance (< 2 L/(m.mg)). Considerable portions of both types of AOM, i.e. extracellular and cellular organic matters are represented by substances with MW < 1 kDa or with MW > 100 kDa. However, the total amount and composition of AOM significantly depend on algal species and their growth. The obtained results imply that the knowledge of AOM...
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