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Microbial production of extracellular polymers and their involvement in stress response
Müllerová, Lucie ; Sedláček, Petr (referee) ; Obruča, Stanislav (advisor)
Bachelor’s thesis is focused on the production of extracellular polysaccharide pullulan by microorganism Aureobasidium pullulans, purification of pullulan and its possible use as a cryoprotectant. As a part of this work a description of A. pullulans, pullulan and an overview of involvement in its stress response were provided. In the experimental part growth characteristics of A. pullulans (the strain CCM 8182 was used) and pullulan production during growth in optimal conditions was analyzed. Biomass production was the highest with fructose as a carbon source (3,580 g/l CCM 8182), the highest pullulan production occurred when using sucrose as a carbon source (10,300 g/l F 148). Among three organic solvents used for pullulan precipitation – ethanol, acetone, isopropylalcohol, ethanol was selected as the best for further experiments in ratio 1:2 (fermentation broth:ethanol). Pullulan purity was characterized by HPLC. As a further part of this work, cryoprotectant properties of pullulan at temperatures – 72° C, -18° C, 4° C and 60°C were studied. The presence of pullulan at temperatures – 72° C and 60° C was found to be detrimental to cell viability. At temperatures – 18° C and 4° C the cryoptotectant activity of the polysaccharide was confirmed.
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Encapsulation of some enzymes into organic particles
Hazuchová, Eva ; Obruča, Stanislav (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on encapsulation of some enzymes into organic particles. The theoretical part is aimed to enzymes, their general characteristics, structure, activity and use, and to encapsulation techniques. Some methods used for analysis of particles, namely the determination of the distribution of particle size using dynamic light scattering, and determining the stability of the particles by the zeta potential, are described too. The experimental part describes methods of preparing particles, methods of determining the encapsulation efficiency and methods for determining particle size and stability. During the experiment part four types of enzymes were encapsulated, partly by manual preparation and partly by encapsulator. Encapsulation efficiency, size and stability of prepared particles were determined too. The particles were exposed to artificial intestinal, gastric and bile juices, as well as the effect of model foods. Subsequently, their long-term stability was observed.
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Utilization of waste from the food industry for wastewater treatment
Nedvědická, Lucie ; Obruča, Stanislav (referee) ; Diviš, Pavel (advisor)
This bachelor thesis disserts about options and issues how to utilize waste from the food industry for wastewater treatment contaminated with heavy metals. The theoretical part describes the general characteristics of heavy metals, as well as the permissible and limit values of these heavy metals in waste water. Furthermore, it is described in this document which chemical methods can be used in order to remove heavy metals from wastewater. This thesis also deals with methods how to analyze the adsorbed amount of sorbed substance, means by using AAS, AFS, AES, MS and ICP – OES methods. At the end of the theoretical part, the issues of the different wastes from the food industry are dealing with and their adsorption ability. In the experimental section it was investigated the tea waste utilization in order to eliminate copper ions from waste water. It has been tested mainly the effect of pH on the adsorption of copper onto tea waste and maximum possible adsorption capacity onto tea waste. The pH optimum for the sorption of cooper from solution onto tea waste was within range 5-6 and the maximum possible adsorption capacity 0,0336 mmol•g-1 was determined. The results indicate that the tea waste could be used as a suitable adsorbent for the purification of waste water, mainly due to good availability, low cost and good adsorption ability of heavy metals.
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System of collagen-hyaluronan in colloidal silver
Sklenářová, Renáta ; Obruča, Stanislav (referee) ; Hurčíková, Andrea (advisor)
The bachelor thesis is focused on the characteristics of solutions of hyaluronan and collagen in colloidal silver. These solutions polysaccharide and protein were prepared at several concentration rows that were analyzed by densitometer from Anton Paar and rheometer from TA Instruments. There were measured density, ultrasonic velocity and viscosity. The aim was to find the optimal ratio of collagen and hyaluronan in colloidal silver, which would suit the transdermal absorption and prepare skin healing spray.
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Enzymatic hydrolysis of wastes associated with coffee production
Kovářová, Markéta ; Skoumalová, Petra (referee) ; Obruča, Stanislav (advisor)
This bachelor thesis is focused on study of potential production of extracellular hydrolytic enzymes by microorganisms – bacterium and moulds, which have been cultivated on spent coffee grounds. The theoretical part deals with characterization of coffee and utilization of coffee by-products. There are also subscribed microorganisms and enzymes which have been noticed. In experimental part coffee ground was used as the sole substrate for production of extracellular hydrolytic enzymes. Productions of protease, cellulase, mannase and lipase enzymes were observed. None-identified isolate of mould spontaneously contaminating spent coffee grounds was identified as the best producer of these enzymes. Subsequently the conditions of cultivation such as water content and shaking vs. static cultivation of this moulds were optimized. Further, we performed partial purification and pre-concentration of the enzyme cocktail by ultrafiltration, ultradialysis and PAGE-SDS characterization of extracellular enzymes was performed as well.
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Biotechnological production of polyhydroxyalkanoates using wastes of coffee production
Vašíčková, Monika ; Benešová, Pavla (referee) ; Obruča, Stanislav (advisor)
This bachelor thesis is focused on study of production of polyhydroxyalkanoates (PHA) by bacteria Burkholderia cepacia and Burkholderia sacchari. Production of PHA has been studied using spent coffee grounds hydrolysates which have been prepared by different aproaches. In the thesis is compared standard method of coffee ground hydrolysis by mineral acid followed by enzymatic hydrolysis. Hydrolysates which have been produced were analyzed in terms of concentration of saccharides and efficiency of hydrolysis. The best producer of PHA (based on results) was bacterium Burkholderia cepacia, in the medium which has been prepared by hydrolysis of spent coffee grounds extracted by 60% solution of ethanol. Biomass yield of this cultivation was 3,553 g/l with 32,472% PHA content. This PHA contained 6,09% 3-hydroxyvalerate. In the other experiment, we verified alternative hydrolysis of spent coffee grounds – by commercially available enzymes. We used cellulase, hemicellulase and the enzymatic cocktail which has been produced by mould. Hemicellulase was the most effective hydrolytic enzyme and its application resulted in production of the highest amount of biomass – 5,708 g/l. In this cultivation, only homopolymer PHB has been which is probably caused by the fact, that during the enzymatic hydrolysis levulinic acid or any other potential precursor of 3HV is formed.
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Involvement of polyhydroxyalkanoates in stress response of bacteria during late stationary phase
Šuráňová, Zuzana ; Sedláček, Petr (referee) ; Obruča, Stanislav (advisor)
The aim of this work was to study the involvement of polyhydroxyalkanoates into stress response of bacteria in the late stationary phase. Bacteria Cupriavidus necator H16 (able to produce PHA) and bacteria Cupriavidus necator H16/PHB-4 (unable to produce PHA) were used for the experiment. In the theoretical part, the polyhydroxyalkanoates and a stress response of bacteria were reviewed. In the experimental part of the work, the involvement of polyhydroxyalkanoates into stress response of bacteria in the late stationary phase against selected stress factors was studied. A resistence against various stress conditions of bacteria was studied. During long term cultivations a culture viability as well as PHA distribution among bacterial populations were assessed by using flow cytometry and the PHA content in biomass was analyzed by gas chromatography with FID detector.. Based on the results obtained in this work, it was found that the PHA acumulating bacteria Cupriavidus necator H16 is capable to survive carbon substrate limitations better than the bacteria Cupriavidus necator H16/PHB. Further, Cupriavidus necator H16 also revealed higher resistence against various stress factors such as ethanol treatment and freezing.
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Application of nanoparticles and nanofibers with active compound in cosmetics
Pavelková, Renata ; Obruča, Stanislav (referee) ; Márová, Ivana (advisor)
Presented bachelor thesis is focused on application of nanoparticles and nanofibers with active compound in cosmetics. The theoretical part is aimed at effect of UV radiation on the skin and compounds that are used in photo protection of the skin. The materials and methods used in nanoparticle and nanofiber preparing were characterized. The experimental part deals with preparing of liposomes and marinosomes with active compound. Particles size, stability measured using zeta potential and stability in model environment were observed. Finally, pilot experiments of optimization of nanofibers preparation using electrospinning were carried out.
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Using image analysis to determine the number of colonies of microorganisms
Kováčiková, Eva ; Obruča, Stanislav (referee) ; Zmeškal, Oldřich (advisor)
This bachelor thesis focuses on the usage of image analysis in the determination of the quantity and of the size of microbial colonies. Microorganism used in the experiment was Saccharomyces cerevisiae, which forms regular shapes of colonies on the solid medium. The applied methods of image analysis were based on wavelet transform. Fractal analysis of digital images was performed using a computer program HarFA and fractal parameters were defined. The obtained data was used for graph representation of distribution and frequency of colonies.
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