|
|
PREPARATION AND CHARACTERIZATION OF BIOPOLYMER-BASED NANOPARTICLES AND NANOFIBERS AND THEIR APPLICATION IN FOOD AND COSMETICS
Kundrát, Vojtěch ; Vilčáková, Jarmila (referee) ; Kráčmar, Stanislav (referee) ; Márová, Ivana (advisor)
The presented dissertation thesis deals with the polymer polyhydroxybutyrate and other biopolymers as a basic building block for the construction of micro- and nanoscopic structures and materials used in food and cosmetics. In the theoretical part, current literary review is prepared to introduce the basics of this application field. The practical part of the work is composed of three blocks developed during the doctoral study. In the first and most important part are summarized comments to the academic and patent outputs, where among the academic ones it is possible to find two peer-reviewed articles dealing with the electrostatic and wet spinning of PHB and properties of prepared materials. The patent outputs consist of several accepted and applied projects, which summarize results on both PHB spinning methods, but also on general approaches enabling the processing of PHB into forms enabling many applications in food and cosmetics. Second part was focused on the patented composition of the UV protection cream based on the prepared nanoscopic and micro- morphologies of PHB. The third block summarizes results focused predominantly on the electrostatic spinning of PHB and other biopolymers. Finally, a short chapter containing a brief description of projects that were in a way related to the dissertation topic, but rather practical development work in Central Tanzania and West Africa, which draw on knowledge and contacts gained during studies at FCH BUT Brno.
|
|
|
Preparation and application particles from copolymer of P(3HB-co-4HB)
Ostanina, Kseniia ; Sedláček, Petr (referee) ; Obruča, Stanislav (advisor)
This bachelor thesis deals with preparation of particles from poly(3-hydroxybutyráte-co-4-hydroxybutyráte). Copolymer was dissolved in acetone and then the solution had been dosed into the anti-solvents. Acetone and anti-solvent are perfectly miscible. Theoretical part focuses on the properties of the copolymer, its production and potential use in medical applications. In the experimental part the copolymer was dripped into selected anti-solvents by syringe and pipette above and below the surface of anti-solvent. The following anti-solvent were chosen: water, methanol, dimethylsulfoxid (DMSO), 50 % acetone-water, 75% acetone-water, 50 % methanol-water, 75 % methanol-water mixtures. There were three copolymers used with different compositions of 4HB units (63 %, 87 % a 33 %). Copolymer composition was analyzed by gas chromatography. Copolymers were prepared by bacterial strain Aneurinibacillus sp. H1. Due to the results particles of size approximately 100-500 nm can be prepared by methods described in this work. The produced particles can be successfully used in medical applications.
|
|
|
Screening of biotechnological potential of selected members of the genus Geobacillus and other related genuses
Kouřilová, Xenie ; Brázda, Václav (referee) ; Obruča, Stanislav (advisor)
This diploma thesis deals with selected thermophilic representatives of genera Geobacillus, Saccharococcus and Bacillus, taking screening of its biotechnological potential into account. Bacteria from the first two genera came from Czech and German collection of microorganisms, while bacteria of genus Bacillus were natural isolates. Researched strains were examined from a viewpoint of carbon source utilization and furthermore, production of biosurfactants, extracellular hydrolytic enzymes (protease, amylase, lipase, cellulase, xylanase), organic acids, antimicrobial agents and microbial plastics – polyhydroxyalkanoates was also tested. Bacteria S. thermophilus, G. uzenensis and G. zalihae evinced a substantial ability of biosurfactant production. Strains G. jurassicus, G. uzenensis, G. gargensis and G. lituanicus were capable of intensive production of all tested, technologically significant enzymes. Highest antimicrobial effects were reached with bacteria G. stearothermophilus and G. thermocatenulatus. Largest production of acetic acid was achieved with G. jurassicus and lactic acid with G. thermodenitrificans. Ability to produce polyhydroxyalkanoates was proved at genotype level by some cultures only, however at fenotype level, response was negative. On the contrary, bacteria genus Bacillus were able to produce polyhydroxyalkanoates, although in small amounts under given circumstances. With remaining researched metabolites, production ability was considerably lower, compared to genera Geobacillus and Saccharococcus.
|
|
|
Analytical methods for determination of polyhydroxyalcanoates content in bacterial cells
Černayová, Diana ; Enev, Vojtěch (referee) ; Sedláček, Petr (advisor)
This bachelor thesis deals with methods that are used for determination of polyhydroxyalkanoates (PHA) in cells of bacteria Cupriavidus necator H16. To the applied methods belong Fourier transform infrared spectroscopy, Raman spectoscopy, turbidimetry and thermal analysis (thermogravimetric analysis and differential scanning calorimetry). The results of each method were compared to amount of PHA determinated by gas chromatography. Fourier transform infrared spectroscopy and Raman spectroscopy revealed a linear relation between ratio of characteristic peaks and amount of PHA. FTIR enabled to determine not only the quantitative amount of PHA, but the quality of the sample (cristallinity, amorphous state) as well. Another method was turbidimetry, which has shown correlation between dispersion of UV-VIS light to amount of PHA in bacterial cells. Thermogravimetric analysis was the most effective technique for determination of PHA. The dependence of weight loss of PHA on its content (found by gas chromatography) was determined with the highest accuracy to gas chromatography. Tha last method- DSC was not alternative replacement for quantitative PHA determination. However, DSC indicated crystalline and amorphous state of the polymer.
|
|
|
Dynamic Model for Production of Polyhydroxyalkanoates by Thermophilic Bacterium S. thermodepolymerans
Křápková, Monika ; Šafránek, David (referee) ; Sedlář, Karel (advisor)
Tato diplomová práce se zabývá rekonstrukcí dynamického modelu produkce polyhydroxyalkanoátů (PHA) termofilní bakterií Schlegelella thermodepolymerans. První kapitola poskytuje čtenářům krátký úvod do systémové biologie a matematické teorie grafů. Na ni navazuje druhá kapitola zabývající se různými přístupy v dynamickém modelování, včetně běžně používaných nástrojů pro dynamickou analýzu komplexních systémů. Třetí kapitola pak sleduje další pojmy a možnosti týkající se analýzy modelu. Následující kapitola se zaměřuje na metabolomiku a často používané laboratorní techniky a pátá kapitola je pak věnována polyhydroxyalkanoátům, zejména jejich chemické struktuře a vlastnostem. V kapitole šesté je navržen obecný booleovský model pro produkci PHA termofilními bakteriemi. Kapitola sedmá se poté zaměřuje na zdokonalení modelu se zaměřením na S. thermodepolymerans. Výsledný dynamický model je podroben analýze a výsledky jsou diskutovány.
|
|
|
Study of biodegradation of poly(hydroxy alkanoates).
Wurstová, Agáta ; Přikryl, Radek (referee) ; Obruča, Stanislav (advisor)
The master‘s thesis is focused on the study of biodegradation of polyhydroxyalkanoates, namely polymer polyhydroxybutyrate. The first part of the thesis is focused on the study of biodegradation of polyhydroxybutyrate in the form of crystalline granules of PHB and PHB films using selected species of microorganisms from bacteria, yeasts and fungi. As a representative of bacteria was chosen microorganism Delftia acidorovans, as yeast was selected Aureobasidium pullulans and Aspergillus fumigatus as fungi. PHB depolymerase activity was measured employing turbidemtiric method with suspension of PHB granules as substrate. The results showed that D. acidorovans can partially degrade PHB. On the contrary A. pullulans cannot effectively degrade PHB. The most significant degradation ability revealed A. fumigatus, which was able to degrade PHB completely. Extracellular enzymes excreted by these microorganisms when cultivated on PHB materials as sole carbon sources were analyzed by SDS-PAGE. The second part of the thesis deals with the biodegradation of PHB in the form of PHB film, PHB hardened foil and PHB Nanoul fabric using standard composting test. Semi-solid cultivation showed positive results. In the interval from 14 days to two months were all forms of the PHB completely biodegraded. With semi-solid cultivation was also studied biodegradation rate of the polyurethane elastomeric films which were modified by partial replacement of polyester polyol by PHB. The test samples were prepared using PHB from Sigma and the PHB samples prepared at the Faculty of chemistry VUT. Samples with different concentrations of the dispersed PHB (1 %, 5 % and 10 %) in the polyurethane were also object of the study. At the end of the cultivation (after 2 months) were measured mechanical properties in tension of the material, then efficiency of biodegradation by gravimetric analysis and modification of the material surface by microscopic analysis.
|
|
|
Screening of extremozyme production of selected extremophilic PHA producers
Dyagilev, Dmitry ; Obruča, Stanislav (referee) ; Pernicová, Iva (advisor)
This bachelor thesis deals with the screening of the production of extracellular hydrolytic enzymes in thermophilic microorganisms of the genera Aneurinibacillus, Brevibacillus, Chelatococcus, Pseudomonas, Schlegelella, Tepidimonas and Caldimonas. The ability of selected enzymes, namely proteases, lipases, amylases, xylanases, cellulases and pectinases, was tested in the investigated microorganisms. Such testing made it possible to assess in which microorganisms the production of specific enzymes can be observed. Based on the results of the screening, it was found that Schlegelella aquatica LMG 23380, Tepidimonas fonticaldi LMG 26746 and the investigated microorganisms of the genus Chelatococcus did not show the ability to produce any of the tested enzymes extracellularly. In natural isolates of Brevibacillus borstelensis LK 99 and Aneurinibacillus thermoaerophilus LK 102, only the ability to produce lipolytic enzymes was detected. The isolate Brevibacillus borstelensis Bz acts as a universal producer of all selected extremozymes. Enzyme activity was determined for selected producers. The bacterium Brevibacillus borstelensis Bz proved the ability to produce all six selected hydrolytic enzymes and has the highest activity of lipases, xylanases, cellulases and pectinases from the tested microorganisms. The highest proteolytic activity was measured in Thermomonas hydrothermalis DSM 14834 when cultured on skimmed milk powder.
|
|
|
Utilization of spent wood chips for biotechnological production of PHA
Ladický, Peter ; Sedláček, Petr (referee) ; Obruča, Stanislav (advisor)
The aim of this work was to study the suitability of wood shavings and sawdust as a substrate for microbial production of PHA by bacteria Burkholderia cepacia and Burkholderia sacchari. In the experimental part of the work the most appropriate approach of hydrolysis of wood shaving and sawdust and the effect of polyphenol and furfural concentration on ability to accumulate PHA was studied. Burkholderia sacchari had greater ability to accumulate PHA compared to Burkholderia cepacia. PHB values 87–89 % were achieved when Bulkholderia sacchari was cultivated on medium that contained detoxified hydrolysate of sawdust. Sawdust is therefore a promising substrate for microbial production of PHA in terms of reducing production costs and high content of PHB in biomass.
|
|
|
Extraction of Poly(3-hydroxybutyrate) from Biomas
Jašek, Vojtěch ; Ing. Jiří Švrček, Ph.D (referee) ; Figalla, Silvestr (advisor)
Polyhydroxyalkanoates are a group of biopolymers which occur in cells of microorganisms. These biopolymers can be considered as alternatives to commonly used petrochemical materials such as polypropylene and polyethylene due to their physical and chemical properties. This bachelor thesis focuses on isolation of particular kind of PHA from biomass and contains both experimental and theoretical part. It consists of information about the origin and usage of PHA, challenges and problems of their biotechnological production and mainly various ways of downstream. Experimental part includes comparison of PHA extraction from biomass done by two ester solvents. Studied parameters were molecular weight of the polymer, solvent extraction ability and their resistance against hydrolysis. The main goal of this thesis was to verify the best process conditions of isolation done by nonhalogenated bio-solvent.
|
|
|
Controlled production of polyhydroxyalcanoates by bacterial strain Ralstonia eutropha using different substrates
Šnajdar, Ondřej ; Duroňová, Kateřina (referee) ; Márová, Ivana (advisor)
This bachelor’s thesis deals with production of polyhydroxyalkanoates (PHA) by bacterial strain Ralstonia eutropha. Production of PHA on different substrates has been studied to lower the costs of feedstock. In theoretical part the review has been done about the most important types of PHA, production strains and possibilities of cultivation of Ralstonia eutropha using different substrates. In practical part there has been studied production of PHA on different vegetable oils, including waste oils from different sources (restaurants, homes, food companies). Incorporation of different precursors for copolymer production control was studied too. The highest yields of poly-3-hydroxybutyrate (P3HB) have been achieved using waste oils. For economical and ecological reasons these oils are very suitable substrates. Using concentration 20 g/l of waste rapeseed oil from university canteen there has been produced 13,32 g/l of biomass containing 58,63% of P3HB in 84th hour of cultivation. The highest yield of PHA in precursors study has been achieved applying 1% propanol in 24th hour of cultivation. The PHA increase has been 97%. This PHA was composed from 91% of 3HB and 9% of 3-hydroxyvalerate.
|
guest ::
