|
|
Preservative systems for natural cosmetics
Koblasová, Dana ; Veselá, Mária (referee) ; Zemanová, Jana (advisor)
The aim of this bachelor thesis is to evaluate the antimicrobial activity of naturally derived preservatives against selected microorganisms. Theoretical part is focused on description of the most used natural, naturally derived and synthetic preservatives, on the safety of preservatives and finally, the issue of contamination of cosmetic products by microorganisms. In experimental part, antimicrobial activity of 4 naturally derived preservatives was evaluated against selected microorganisms, which were bacteria Micrococcus luteus, Kocuria rosea, Bacillus cereus, Bacillus subtilis, Serratia marcescens and one yeast Candida vini. The tested preservatives were from MinaSolve company - E-LEEN Green A, which contains pentylene glycol and phenylpropanol, E-LEEN Green OR, which is composed of citrus extracts, citric acid, ascorbic acid and pentylene glycol, Green B, which contains benzoic acid, sodium benzoate and pentylene glycol and Hexam+, which is a mixture of pentylene glycol and hexamidin diisethionate. Antimicrobial activity was evaluated by agar diffusion method. The highest antimicrobial activity showed Hexam+, the lowest E-LEEN Green OR. E-LEEN Green A and Green B did not show any antimicrobial activity against any microorganism in the 1% tested concentration. The measured values of the inhibition zones show that the most resistant microorganisms from all the tested in this thesis are Bacillus cereus and Bacillus subtilis and the least resistant are Micrococcus luteus and Kocuria rosea.
|
|
|
Microbiology of raw milk and milk after treatment
Pláničková, Jana ; Vítová, Eva (referee) ; Omelková, Jiřina (advisor)
The aim of this bachelor thesis is microbiology of raw milk and heat treatment milk, pasteurized and UHT treatment. There are described the most important and the most common microorganisms that contaminate milk, spoilage and pathogenic in the theoretical part. Practical part was provided in laboratory of diary factory. There were determined counts of microorganisms in raw, pasteurized and UHT milk by microbiological analysis.
|
|
|
Importance and utilization of cellulases
Stuchlíková, Olga ; Babák, Libor (referee) ; Omelková, Jiřina (advisor)
The theoretical part of my bachelor thesis focuses on studying plant cells and polysaccharides, from which the cell wall is made of. The main attention is held on cellulose. Secondly, cellulases and microorganisms, which produce these enzymes, are mentioned. This work also deals with the actual use of cellulases in industry and agriculture. The last chapter of the theoretical part is devoted to immobilization, immobilized enzymes and their use in practice. The practical part of my bachelor thesis focuses on determination of basic properties of commercially used enzyme Celluclast 1.5 L. The temperature and pH optimum and temperature and pH stability were determined experimentally. The attention is also held on immobilization of these cellulases on synthetically prepared carrier „Sorsilen“. Subsequently, basic characteristics were determined as well as for soluble form of commercial enzyme.
|
|
|
Design and Operation of Water Disinfections Plants
Krupicová, Simona ; Rajnochová, Markéta (referee) ; Kučera, Tomáš (advisor)
In the first part of my bachelor thesis I deal with individual disinfectants used for hygienic supply of drinking water based on chlorine and without chlorine. Then I mention the operation without chlorine disinfectants. In the second part of this thesis I describe individual plants using various disinfection methods and at the end of the thesis I compare these methods and use it in practice.
|
|
|
Monitoring of selected parameters in the wastewater treatment process in the various WWTP
Dalajková, Nikola ; Zlámalová Gargošová, Helena (referee) ; Repková, Martina (advisor)
This work is focused on wastewater treatment, specifically the WWTP Brno Modřice. Described herein are the general technological parameters of large and medium-sized wastewater treatment plants and wastewater treatment process in the WWTP Brno Modřice. The greatest emphasis is on biological phase of waste water treatment. Purification employs chemical, biological and physical cleaning processes. To determine the effectivness of the treatment plants various indicators are used such as COD, BOD, Ntotal and Ptotal whose the maximum permissible values are established in accordance to norm. The basis of biological treatment is the activated sludge containing microorganisms, by which the effectiveness of the cleaning process is determined. These microorganisms are determined qualitatively and quantitatively. To compare the efficiency measurements of activated sludge were also made at two other wastewater treatment plants. These values were then compared in the experimental part of the work.
|
|
|
Silver based raw materials for cosmetic purposes
Čaková, Adriana ; Ďubašáková, Mária (referee) ; Zemanová, Jana (advisor)
The purpose of this bachelor’s thesis was a research about silver based cosmetic products and determination of antimicrobial activity on certain species of microorganisms by chosen silver based cosmetic products. Theoretical part is focused on the problematics of silver based cosmetic products, on their main purpose, physically chemical characteristics and toxicological profile. In the theoretical part is also mentioned problematics of legislative, mainly the safety and real effectivity of tested cosmetic products. Experimental part was focused on determination of antimicrobial activity of chosen silver based cosmetic products. Two silver based cosmetic product were used to determined antimicrobial activity on selected microorganisms Bacillus subtilis, Bacillus cereus, Micrococcus luteus, Kocuria rosea, Serratia marcescens a Candida vini. From result it is apparent, that both of used Cosmetic product showed antimicrobial activity, but not on every used microorganism.
|
|
|
The influence of thermal treatment on life of particular food products.
Žůrková, Pavla ; Ing.Gabriela Dereňová (referee) ; Ing.Petr Koflak (advisor)
This work deals with influence of heat processing on longevity of two selected products of the packing company Seliko trading a.s. For the research there were selected products Sterilised sauerkraut in sweet-sour pickle and Fatback spread. Evaluation has been done in laboratory premises of the packing company. There has been monitored mikrobiological stability after heat processing and sensory properties of the mentioned products always with an interval of one month. During the monitored seven months there appeared changes in taste and consistence of the products that are not defective in these products. The microbiological test taken after seven months was negative, just like at the beginning of the experiment. The result of the given findings is that the heat sterilisation was efficient and that during the storage there did not rise number of micro-organisms in the products.
|
|
|
The Influence of Microbial Degradation of Biochar in Soil on its Physico-chemical Properties
Kurková, Marie ; Weidlich, Tomáš (referee) ; Kalina, Michal (advisor)
This master‘s thesis studies the different factors that can affect biochar in soil and cause its degradation. These factors include irrigation, root exudates and the action of microorganisms. In the experimental part, the degradation of biochar in the soil environment was studied in two ways, firstly without the action of microorganisms, where the effect of irrigation was simulated by leaching biochar in ultrapure distilled water and model rainwater, and the effect of root exudates was simulated by extracting of biochar in citric acid as a model root exudate of maize sown. The extracted biochar solutions without prior cultivation in soil were characterized by pH, conductivity, UV-VIS analysis and elemental analysis. The biochar residues after extractions were characterized for morphology by SEM, structural differences by FTIR, and organic and mineral content by TGA analysis. The biochar samples after cultivation in soil were subjected to extractions under the same conditions and the same analyses were performed. The effect of cultivation in soil on biochar resulted in a change in elemental composition, a decrease in biochar alkalinity and changes in the ratio of organic matter and mineral fraction were observed. The decrease in pH and conductivity of biochar was mainly related to potassium leaching. The structural and morphological analysis indicated that there is no significant degradation of the structure of the biochar due to washing or cultivation in soil, but there is a partial fouling of the biochar pores by low molecular weight impurities from the soil. These results suggest a short-term action of biochar in soils as a source of nutrients (potassium, phosphorus) and, conversely, a long-term action as a soil conditioner.
|
|
|
Dissolved Air Flotation – From Pilot Plant to Full Scale Implementation
Dobiáš, Pavel ; Hlaváč, Jaroslav (referee) ; Janda,, Václav (referee) ; Vávrová, Milada (referee) ; Dolejš, Petr (advisor)
The thesis deals with the use of dissolved air flotation (DAF) in water treatment technology in the Czech Republic. It summarizes the knowledge gained at pilot plant studies as well as the experience with full-scale flotation units which have been built in potable water treatment plants in the Czech Republic in years 2006-2018. This thesis provides a broad background of experimental studies of a modern separation process, which does have great advantages in the removal of natural organic matter and microorganisms from water in the drinking water treatment industry. In this thesis, there are presented some examples of the excellent efficiency of the microorganisms removal, both under the experimental conditions as well as water treatment plants, which were improved by DAF units installation in full scale. In addition to the high separation efficiency, it is shown, how DAF units could influence the subsequent separation steps as for example filtration through the granular media. The negative influence of the pre-ozonization on the DAF separation efficiency in Hradec Králové WTP is demonstrated too. The results of the pilot experiments support the idea, that the key condition for high removal efficiency is the optimal coagulation process chemistry. Design of pilot experiments was based on the factorial planning theory and some results are discussed in this thesis. The very big portion of the pilot experiments was made for estimating of the full-scale DAF design parameters before the water treatment plants reconstruction phase
|
|
|
Use of plasma jet for biomedical application
Doubravová, Anna ; Márová, Ivana (referee) ; Skoumalová, Petra (advisor)
This master´s thesis is focused on the utilization of the sterilization effects of low temperature plasma towards the bacterial microorganisms that occur mainly on the human skin. The plasma sterilization process is fast efficient, non-toxic, environmentally friendly, cost-effective and safe for the operating staff as well as for the patient. Another advantage of using low temperature plasma is to support cell proliferation and wound healing. By combining these advantages, an effective method can be obtained, which would sterilize the wounds sparingly with regard to the surrounding healthy tissue and support the regeneration of the damaged tissue at the same time. In the experimental part, gram positive and gram negative bacteria were used to prove the sterilization effects with respect to different cell wall structure. Staphylococcus epidermidis and Propionibacterium acnes, which cause purulent skin inflammations, were used as gram-positive microorganisms. Serratia marcescens and Escherichia coli were selected from gram positive bacteria. These model organisms were inoculated at various concentrations on culture broths and treated by plasma at a distance of 1 mm from the agar surface. The microwave discharge was generated in argon at a power of 9 W, a gas flow rate of 5 l / min and water cooling to avoid thermal effects on the treated surface. Subsequently, model skin cells of HaCaT were exposed to low temperature plasma and tested for plasma cytotoxicity to demonstrate its healing effects. The obtained results make it possible to state that the sterilizing effects of low-temperature plasma in all tested gram-positive and gram-negative bacterial strains are verified in this work. Finally, tests were demonstrated using a suitable method of the treatment on human skin cells, where the safety and usefulness of the tested low-temperature plasma was demonstrated when applied to shorten the healing process.
|
guest ::
