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Development of active supplement with probiotics
Cveček, Jan ; Dzurická, Lucia (referee) ; Márová, Ivana (advisor)
Subject of this bachelor thesis was to investigate the antimicrobial activity of selected probiotic strains and determine how the probiotic growth is affected probiotic growth by prebiotics and essential oils. Probiotics are bacteria, which positively affect human health. They are mainly used in food industry as fermentation starter cultures, where they produce antimicrobial compounds that support resistance to pathogenetic bacteria during the fermentation process. In general, fermentation process is used to prolong the shelf-life of foodstuff. However, the applications of probiotics are very limited in food or other industry because probiotics are living organisms, so at least the industry tries to use their metabolic products. The method of encapsulation could support the usage of probiotics in other unusual ways. In experimental part of this thesis, the growth of probiotics was studied in both commercial MRS broth and in minimal broth, which could help with isolation of bioactive metabolic products such as lactic acid and bacteriocins. Additionally, the effect of prebiotic-inulin and essential oils from oregano and thyme on probiotics growth was investigated. In the second part of thesis, the content of lactic acid was analysed and antimicrobial activity of selected probiotic strains and effect of additives on activity was tested. Antimicrobial test discovered that prebiotics and essential oil from thyme enhanced the antimicrobial activity of tested samples. Also, the minimal broth was shown to be unsustainable for cultivation of used probiotics because selected strains exhibited small production of biomass and very low antimicrobial activity. In the third part, the probiotic strain was encapsulated with prebiotic and essential oil into alginate particles. Bacterial growth from the particles in MRS broth was investigated over period of 15 days. Results of this measurement were that probiotics were gradually released from particles over the period. Subsequently the potential use of these particles was proposed for further investigation.
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Influence of some medicinal fungi and other prebiotics on growth and metabolism of probiotic bacteria
Husová, Martina ; Bendová, Agáta (referee) ; Márová, Ivana (advisor)
The bachelor thesis deals with the influence of medicinal mushrooms and other prebiotics on the growth and biological activity of probiotic bacteria. Selected genera of lactic acid bacteria Bifidobacterium and Lactobacillus can produce antimicrobial substances bacteriocins and their production depends on cultivation conditions and available nutrient sources. The theoretical review describes and characterizes probiotic bacteria, their metabolism and importance for human health. Similarly, the theoretical section focuses on prebiotics and their selected representatives, which are four species of medicinal fungi, the microscopic algae Chlorella, resistant starch, the cell biomass of the yeast Saccharomyces cerevisiae and dietary supplements such as inulin and psyllium. In the experimental part, extracts were prepared from these prebiotics by three different methods - boiling, macerating and hydrolysis. The obtained extracts were characterized in terms of macronutrient content such as carbohydrates and proteins. Based on the growth of four species of lactic acid bacteria cultured in standard medium and their production of antimicrobial substances, a strain of B. bifidum was selected for cultivation in the presence of prebiotic extracts. After determining the increase in probiotic biomass in the prebiotic extracts, the cultures were centrifuged, and the protein content of the bacterial supernatant was determined. The lactic acid content of the lyophilized probiotic extracts was determined by high-performance liquid chromatography, and finally, the antimicrobial activity was determined by broth dilution method and resazurin viability assay. The results of the antimicrobial tests were compared with the antimicrobial activity of lactic acid at the same concentration as that contained in the probiotic extracts. For the highest macronutrient content of the prebiotic extracts, extraction by boiling was the most suitable method. For insoluble polysaccharides such as resistant starch, hydrolysis might be a better option, but this requires subsequent treatment of the extract to provide suitable conditions for cultivation. The boiled extracts were the best for the growth of probiotic bacteria as well as their production of antimicrobial substances. The highest concentrations of protein and lactic acid were measured in these samples. The likely presence of bacteriocins was confirmed in all culture types. Almost all probiotic extracts showed antimicrobial activity against Staphylococcus epidermidis and Escherichia coli. The likely presence of bacteriocins was confirmed by the broth dilution method, for example in extracts containing chlorella algae or S. cerevisiae yeast, because these extracts were antimicrobial at lower concentrations than the lactic acid present.
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Polymerization of Lactides in the Melt
Horkel, Ondřej ; Tomala, Libor (referee) ; Petrůj, Jaroslav (advisor)
This bachelor thesis deals with the problematics of Lactide polymerization in the melt. Theoretical part summarizes properties of lactic acid, lactides and polylactides as well as currently used methods of their preparation. In experimental part, a set of three experiments was designed, namely dependance of viscosity average molecular weight on catalyst concentration, polymerisation temperature and polymerisation time. This was achieved by measuring cinematic viscosity using Ubbelohde viscosimeter. As a result of these experiments, it was found that one of posssible combinations of conditions resulting in high molecular weight polymers is the following: concentration ratio of catalyst towards lactide 110–4, polymerisation teperature 160 °C and polymerisation time 3 hours.
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Preparation and characterization of unsaturated bio-polyester resins
Žůrek, Michal ; Petrůj, Jaroslav (referee) ; Figalla, Silvestr (advisor)
The theoretical part of this work is devoted to the selection of suitable components for synthesis of a branched oligoester and their structural arrangement. Further, oligomers of lactic acid esterified with crotonic acid branched by erythritol or pentaerythritol are discussed. Crosslinking of prepared oligoesters is accomplished by free radical mechanism using vinyl acetate as reactive diluent and 2,2'-azo-bis-isobutyronitrile as initiator. Resin was cured by vinyl acetate in different mass ratios. Results show that there in an optimal ratio for curing between oligoester and reactive diluent. Using less vinyl acetate results in insufficient crosslink density or, on the contrary, using considerable excess of vinyl acetate causes rapid polymerization, that also results in lower density of crosslinking. The crosslink density was determined indirectly by extraction of the soluble part to acetone after curing and drying of the product.
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Study of Production and Using Mesolactide
Gažo, Peter ; Porubský, Tomáš (referee) ; Petrůj, Jaroslav (advisor)
This bachelor thesis deals with mesolactide production of D,L-lactic acid. In the theoretical part, it has been processed literature review focused on manufacturing methods of mesolactide,it´s processing and using. In the practical part, it has been investigated conditions linked to the most appropriate production of mesolactide.
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Bio-based composites made from lactic acid resins
Smiřický, Jan ; Černý, Miroslav (referee) ; Figalla, Silvestr (advisor)
This bachelor thesis is about the synthesis of polyurethane glue, which is capable of gluing together sawdust, and about the testing of the mechanical characteristics of the glue and sawdust compostion. This glue is biodegradable and is created from renewable resources, this is why it could be an appropriate replacement for phenol formaldehyde, melamine, and urea formaldehyde resins. Another indisputable advantage is the absence of arenes in the macromolecule structure, which can be carcinogenic. In this synthesis, the compounds polylactic acid and hexamethylene diisocyanate were chosen, the former as the polyol and the latter as the isocyanate. In the theoretical section of the thesis, the used compounds are described in terms of their characteristics, their creation and the tests of the composites as well. In the experimental section, the conducted experiments are described.
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Thermotolerant strains application for preparation of selected metabolites on waste hydrolysates
Musilová, Kristína ; Vítová, Eva (referee) ; Babák, Libor (advisor)
This Bachelor´s Thesis deals with the preparation of the selected metabolite on hydrolysates of orange fruit waste, specifically on orange peel hydrolysates using thermotolerant strains. The thermotolerant Bacillus coagulans strain having lactic acid as the primary metabolite, a substance with a great perspective, was selected for the fermentation process for its exceptional properties. At the beginning of the experiment, optimal conditions for the growth of the selected microorganism were determined; these were applied during the fermentations. Several fermentations were performed under various conditions until those conditions were determined, in which lactic acid was produced. The fermentation production was determined by the HPLC method and the saccharide decrease by the Somogyi-Nelson method. To achieve lactic acid production, it was necessary to extract the orange peels by an organic agent before fermentation, in order to eliminate substances causing inhibition of micro-organism growth. Higher yields were achieved by the SHF method, but the highest by using the Lactobacillus casei strain.
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Selected bioengineering characteristics of lactic acid bacteria
Šťásková, Lucie ; Vítová, Eva (referee) ; Babák, Libor (advisor)
The diploma thesis deals with the growth of biomass and production of selected metabolit–lactic acid by thermophilic bacteria Bacillus coagulans. The resulting selected metabolite was determined by HPLC method. Cultivations of this genus were performed on synthetic media, where the influence of carbohydrate used as carbon source was tested. Lactose was more suitable fot growth of biomass and glucose for production of lactic acid. On natural whey media the influence of different conditions were tested. The highest yields of biomass and production of lactic acid were observed on enriched whey medium. The last part deals with comparing the production of biomass and metabolites, depending on the volume of media. There were compared selected bioengineering characteristics of all cultivations.
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Modeling and cultivation of some microorganisms on waste substrate hydrolysates
Kecskésová, Viktória ; Obruča, Stanislav (referee) ; Márová, Ivana (advisor)
The aim of Diploma thesis was the cultivation of microorganisms Lactobacillus plantarum CCM 7039 and Bacillus coagulans CCM 2658 on hydrolysed spent coffee grounds, production of lactid acid and modelling of these processes to find out more detailed characteristics. First, both microorganisms were cultivated in Erlenmeyer flasks on spent coffee grounds hydrolysate containing lipids and processed by extraction of lipids, e.g. lipid-free. The effect of nitrogen source and inoculation medium were monitored in the course of cultivation. The optimal conditions found were used for subsequent fermentation in bioreactors. Further, microorganisms were cultivated in the Erlenmeyer flasks in the media with individual carbohydrates typical for hydrolysed spent coffee grounds to determine its ability to utilize these carbohydrates. By fermentation in the bioreactors, the yield of lactic acid from carbohydrates was 97 % in Lactobacillus plantarum and 99 % in Bacillus coagulans, respectively. Models for growth and productivity of microorganisms were processed in MATLAB using logistic, generalized logistic and Monod functions. In general, the best data fit was achieved using a logistic function.
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UTILIZATION OF FOOD PROCESSING WASTE FOR LACTIC ACID AND ETHANOL PRODUCTION
Hudečková, Helena ; Kráčmar, Stanislav (referee) ; Buňka, František (referee) ; Márová, Ivana (advisor)
The doctoral thesis is focused on the microbial production of lactic acid and ethanol using food processing waste as substrate. Coffee processing waste (spent coffee grounds), wine production waste (grape pomace) and orange processing waste (orange peel) were chosen as substrates for experiments. The theoretical part is dedicated to summarizing current knowledge about waste from food production and possibilities of its processing. It also deals with selected metabolites (lactic acid, ethanol) to which these wastes can be used. Part of the experiments was focused on the characterization and optimization of hydrolysis to maximize the amount of fermentable saccharides. Different combinations of chemical, physical and enzymatic hydrolysis of selected substrates have been tested. Subsequently, a suitable strain for lactic acid and ethanol production was searched for. In the case of lactic acid production, 7 bacterial strains were selected (Lactobacillus casei CCM 4798, Bacillus coagulans CCM 2013, Bacillus coagulans CCM 2658, Lactobacillus rhamnosus CCM 1825T, Lactobacillus delbruckii subsp. bulgaricus CCM 7190, Lactobacillus plantarum CCM 7039T, Streptococcus thermophilus CCM 4757). These strains were first cultivated on the synthetic media containing different kind of saccharides. Afterward, the cultivation on the waste biomass hydrolysates were tested. In the case of ethanol production, 2 yeast strains kmeny (S. cerevisiae CNCTC 6646 a S. cerevisiae CNCTC 6651) were cultivated on hydrolysates of individual waste substrates. Subsequently, the experiments focused on the production of lactic acid and ethanol on hydrolysates of waste biomass in bioreactor were done. The last part of this doctoral thesis deals with the microaerobic pretreatment of lignocellulosic biomass to increase the production of organic acids during the acetogenic phase of anaerobic digestion.
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