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Growth characteristics of thermophilic microorganisms
Kuchtová, Ludmila ; Vítová, Eva (referee) ; Babák, Libor (advisor)
The aim of this work was focused on study of influence of cultivation conditions on growth of thermophilic bacteria Thermus aquaticus, Thermus scotoductus, Geobacillus thermodenitrificans and Geobacillus thermocatenulatus in cultivation medium recommended by Czech Collection of Microorganisms (CCM). The change of concentration of biomass during cultivation with various pH of media, cultivation temperature, agitation rate and with addition of glucose to medium during cultivation in Erlenmayer flasks was observed. Results served for determination of optimal growth conditions for each microorganism. After optimal growth conditions were obtained, cultivations in fermenter were performed. Growth curves were made from values of absorbance and dry weight of samples.
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Microbial production of lipid substances using waste substrates
Árendásová, Veronika ; Szotkowski, Martin (referee) ; Němcová, Andrea (advisor)
This bachelor’s thesis examines the issue of lipid production, done through selected Metschnikowia strains gained from waste starch substrates. Produced lipids are extensively used in biotechnological processes. Cultivation utilised waste starch substrates, left over from food production, as they constituted an available and economical material. The study also monitored the growth of individual Metschnikowia strains in laboratory and reduced temperatures, using an optimal medium. The yeast’s production properties were analysed by means of gas chromatography. All selected Metschnikowia strains were able to produce lipid from waste substrates. Lipid production increased when a mixture of glucose and waste substrates was used. The amount of lipids and the share of fatty acids strongly depended on the strain and cultivation conditions. In all examined strains, monounsaturated fatty acids were represented most strongly. The Metschnikowia pulcherima 149 adapted best to waste substrates.
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Metabolite production by some strains of industrial yeasts in various phases of cell growth
Jankeje, Kristína ; Kubešová,, Jitka (referee) ; Kočí, Radka (advisor)
Presented bachelor thesis is focused on industrial application of chosen yeast strains. Principal interest of work is to study production of primary and secondary metabolites during individual growth phases. Optimal growth conditions as well as influence of exogenous stress factors (mainly oxidative and/or salt stress) on cell growth and yeast metabolism are discussed. In experimental part growth curve of industrial strain Phaffia rhodozyma was determined. Biomass increase (maximum in 90th hour 5,441 g/l), astaxanthin production (secondary metabolite) and/or ergosterol biosynthesis (primary metabolite) were observed. The best ration of astaxanthin to total carotenoids was 50 %. Next studied metabolite was ergosterol, its total amount in dry biomass was 0.11 %. In conclusion astaxanthin amounts produced in optimal growth conditions were compared with yields obtained under stress cultivations. Results of stress experiments illustrate positive influence of stress factors on cell growth as well as on astaxanthin biosynthesis. Low concentration of salt (2% NaCl) added in inoculum with 5 mM hydrogen peroxide in production medium would be the best combination in industrial applications.
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Biological role of PHA cycle in bacterium Rhodospirillum rubrum
Šarköziová, Patrícia ; Obruča, Stanislav (referee) ; Slaninová, Eva (advisor)
The diploma thesis deals with the study of polyhydroxyalkanoates (PHAs) production and their protective effects during exposure of the bacterial strain Rhodospirillum rubrum to various stress factors. The theoretical part of this work is focused on the characterization of PHAs and used bacterial strain. In the first part of the experimental work carbon substrates for biomass growth and PHA production in different time intervals (24, 48, 72 and 96 hours) were investigated. Acetate, fructose, hexanoate and malate served as a carbon source. The second part of this work was focused on the selection of a suitable fluorescent probe for the bacterium Rhodospirillum rubrum (propidium iodide, SYTOXTM, fluorescein diacetate), which was used to determine the viability of bacterial cells using flow cytometry. This method was used to determine the viability of bacterial cells after their exposure to various stress factors (thermal stress, freezing and thawing, ethanol stress, osmotic stress, peroxide stress, pH stress and UV stress). Finally, the growth curve of bacteria Rhodospirillum rubrum was determined by measurement of the optical density.
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Preparation of selected microbial metabolites from waste materials
Jechová, Iva ; Vítová, Eva (referee) ; Babák, Libor (advisor)
This diploma thesis deals with the biodegradation of whey on selected microbial products (carbohydrates, lactic acid, acetic acid and ethanol) thermophilic bacteria of genus Thermus aquaticus and mesophilic bacteria of genus Lactobacillus casei and Bacillus coagulans. For cultivation was used as medium whey, from which the proteins were removed and which was enriched with nutrients. On the basis of culture in the fermentor were determined growth curve and the HPLC method were determined individual bioremediation products.
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Study of growth and metabolic properties of selected microorganisms
Hudečková, Helena ; Šupinová, Petra (referee) ; Babák, Libor (advisor)
The aim of this Bachelor thesis was study of the growth and production of selected metabolites of microorganisms, namely Lactobacillus casei and Saccharomyces cerevisiae. Microorganisms were cultivated in Erlenmeyer flasks by using the recommended media for their growth. The growth curves were determined from the values of optical density and concentration of biomass. Samples were then analyzed by HPLC for determination of the content of glucose and ethanol in S. cerevisiae and the content of glucose and lactic acid by L. casei.
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Mathematic modeling of microorganisms growth
Kecskésová, Viktória ; Obruča, Stanislav (referee) ; Babák, Libor (advisor)
The aim of Bachelor thesis was mathematical modeling of microbial growth, namely Lactobacillus casei CCM 4798. Microorganism was cultivated in Erlenmeyer flasks by technique batch cultivation. Used media were composed with recommended chemicals for the growth of lactobacilli and various concentrations of substrate. Subsequently, the growth curves were determined in two ways, as the dependence of optical density to time and the concentration of dry biomass per time. It were selected three suitable models, model of exponential growth, Monod model and Tessier model. Further, using MATLAB, application Curve Fitting Toolbox and mathematical models was modeled exponential phase of growth curves. According to statistics in MATLAB it was founded that the best fit was enabled of model of exponential growth.
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Je zooplankton schopen živit se pikoplanktonními sinicemi?
ŠVECOVÁ, Miroslava
The aim of the bachelor thesis is to look into the composition of waters and focus on the investigation of picocyanobacteria. Theoretical part mainly covers ecology, morphology, species diversity and distribution of these organisms. A significant part of the bachelor thesis also deals with the consumption of picocyanobacteria by zooplankton in various areas. The practical part contains research of growth curve of picocyanobacteria performed on six different cultures grown in two cultivation media for 84 days. During this period, individual samples were taken regularly. The research displays interesting results about growth of picocyanobacteria in dependence on observed time, cultivated medium and type of culture.
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Biological role of PHA cycle in bacterium Rhodospirillum rubrum
Šarköziová, Patrícia ; Obruča, Stanislav (referee) ; Slaninová, Eva (advisor)
The diploma thesis deals with the study of polyhydroxyalkanoates (PHAs) production and their protective effects during exposure of the bacterial strain Rhodospirillum rubrum to various stress factors. The theoretical part of this work is focused on the characterization of PHAs and used bacterial strain. In the first part of the experimental work carbon substrates for biomass growth and PHA production in different time intervals (24, 48, 72 and 96 hours) were investigated. Acetate, fructose, hexanoate and malate served as a carbon source. The second part of this work was focused on the selection of a suitable fluorescent probe for the bacterium Rhodospirillum rubrum (propidium iodide, SYTOXTM, fluorescein diacetate), which was used to determine the viability of bacterial cells using flow cytometry. This method was used to determine the viability of bacterial cells after their exposure to various stress factors (thermal stress, freezing and thawing, ethanol stress, osmotic stress, peroxide stress, pH stress and UV stress). Finally, the growth curve of bacteria Rhodospirillum rubrum was determined by measurement of the optical density.
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Microbial production of lipid substances using waste substrates
Árendásová, Veronika ; Szotkowski, Martin (referee) ; Němcová, Andrea (advisor)
This bachelor’s thesis examines the issue of lipid production, done through selected Metschnikowia strains gained from waste starch substrates. Produced lipids are extensively used in biotechnological processes. Cultivation utilised waste starch substrates, left over from food production, as they constituted an available and economical material. The study also monitored the growth of individual Metschnikowia strains in laboratory and reduced temperatures, using an optimal medium. The yeast’s production properties were analysed by means of gas chromatography. All selected Metschnikowia strains were able to produce lipid from waste substrates. Lipid production increased when a mixture of glucose and waste substrates was used. The amount of lipids and the share of fatty acids strongly depended on the strain and cultivation conditions. In all examined strains, monounsaturated fatty acids were represented most strongly. The Metschnikowia pulcherima 149 adapted best to waste substrates.
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