|
| |
|
| |
|
|
Testing of anti-microbial and anti-adhesive properties of nanodiamond materials
Jurková, Blanka ; Beranová, Jana (advisor) ; Lišková, Jana (referee)
Nanocrystalline diamond (NCD) films possess great mechanical properties (low friction coefficient, high hardness etc.), chemical properties (e.g. low corrosivity or chemical inertness) and good biocompatibility. This makes them perspective materials for protective coatings of medical implants and devices. As bacteria biofilms are often very resistant to antibacterial treatment, materials with anti-bacterial or at least anti-adhesive properties are needed. The interaction of NCD films with bacteria has not been properly examined yet. The aim of this thesis was to introduce and optimize the methods for routine bacterial biofilm cultivation and analysis, use them to investigate the ability of NCD films to inhibit the attachment and biofilm formation of Escherichia coli and correlate it with the NCD surface hydrophobicity. The materials used for the study were hydrogenated NCD (hydrophobic), oxidized NCD (hydrophilic) and uncoated glass. For bacterial biofilm growth, cultivation in six-well plates and continuous cultivation in CDC Bioreactor was used. Several methods were tested for quantitative biofilm detachment and analysis. The putative anti-bacterial properties of NCD material were not confirmed in this work. Higher bacterial attachment to NCD films in comparison to the uncoated glass was...
|
|
|
Influence of expression of lmr(C) on the biosynthesis of lincomycin in Streptomyces lincolnensis: Resistance or production?
Veselá, Ludmila ; Balíková Novotná, Gabriela (advisor) ; Beranová, Jana (referee)
The genus Streptomyces produces more than a half of the known bioactive substances, ranking it among the most important bacterial taxons. Streptomyces lincolnensis ATCC 25466 encodes a biosynthetic gene cluster for lincomycin biosynthesis in its genome. Apart from the biosynthetic and regulatory genes, the cluster also contains three resistance genes, lmr(A), lmr(B) a lmr(C), which could protect of the host from the toxicity of a synthesized antibiotic. The Lmr(C) protein belongs to ARE proteins which generaly confer resistance to clinically important classes of antibiotics: macrolides, streptogramins, lincosamides and pleuromutilins. In addition to antibiotic producers, ARE proteins are also present in pathogenic microorganisms. However, the resistance mechanism conferred by these protins which belong to ABC transporters, even though they lack the transmembrane domain, have not been characterized yet. This makes the ARE proteins an interesting subject of the research. Using deletion mutants in resistance genes lmr(A), lmr(B) a lmr(C) we studied their effect on the lincomycin production and resistance to lincosamides, lincomycin and clindamycin with special focus on the function of the lmr(C). We have found that deletion of lmr(C) does not significantly influence lincomycin production and...
|
|
|
Changes in vegetation of Karpaty since glacial maximum - identificaition of main trends accesibility of data and gap in knowledge
Beranová, Jana ; Kuneš, Petr (advisor) ; Jamrichová, Eva (referee)
The Carpathian Mountains are great range in Europe. This rewiew is target to identify main evolution trends of vegetation i Carptahian Mountatins. I studied materials whitch was concetrate to pollen analysis and malacological finds. Based on this materials I found that in the stadial dryas periods there were climatic conditions for small forrest islands mainly formed from genus Pinus and Larix. In the interstadial periods the different climatic conditions permit forrest propagation and became denser. Transitions from pleistocen to holocen was nearly similar to the situation in interstadial period. But later in the holocene the density of the forest is growing more and dominant of late glacial forest was replaced mainly by the spurce. Population of plants that survive the glacial in the Carpathian mountain growing as same as and new species that survived glacial in warmer localities. In the subatlantic and especially in the few last decade the human efect is important and can be found in the pollen analysis. On the research of plant evolution in Carpathian mountain is necessary to continue, mainly on identification and analysis new localities. This large area is unequaly covered by localities.
|
|
|
Bacterial adhesion to surfaces
Budil, Jakub ; Beranová, Jana (advisor) ; Kuthan, Martin (referee)
Bacterial adhesion is a process of attachment of a planktonic cell to the surface and the necessary step for further biofilm formation. Most bacterial species are capable of biofilm formation. Bacteria within biofilm exhibit increased resistance to antibiotics and other external factors, which makes the eradication of adhered bacteria rather difficult. Bacterial adhesion is very complex process affected by many physical and chemical factors as well as by the adhesive molecules present on the substrate and cell surface. Accurate description of these factors enables to design appropriate modifications of both the substrate and the environment with the aim to fabricate the antiadhesive and antibacterial surfaces or to increase the efficiency in bacteria-based biotechnological processes. Whereas in medical applications the main goal is to decrease bacterial adhesion, the increased adhesion is desirable in certain processes employing bacteria, as is for example the wastewater treatment. This thesis reviews main theories used for prediction of bacterial adhesion, describes the process of adhesion and physical, chemical and biological factors that influence it. It also contains an overview of antiadhesive and antibacterial surfaces. Key words: Bacteria, adhesion, pili, flagellum, antiadhesive and...
|
|
|
Nanoparticles for gene editing
Kružíková, Zuzana ; Grantz Šašková, Klára (advisor) ; Beranová, Jana (referee)
Early DNA-based therapies were tested for therapeutic applications, but they sooner or later revealed multiple hurdles and risks preventing their use in further clinical trials. Recently, they have been replaced by rapidly evolving gene editing using programmed nucleases capable of precise genome modifications by cleaving specific DNA sequences. Zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and CRISPR/Cas9 system are currently under investigation as potential therapeutics. However, their off-target effects must be controlled. Targeted delivery of nucleases in a form of mRNA seems as the most promising method. Various types of nanoparticles enable mRNA transfer and could be used to facilitate the nuclease application. Some of these nanoparticles together with characterization of the programmed nucleases are described in this thesis.
|
|
|
Microdomains in freshwater sediment as a driving factor in the biogeochemical processes
Duchoslav, Vojtěch ; Falteisek, Lukáš (advisor) ; Beranová, Jana (referee)
A natural arsenic anomaly at Mokrsko is a site of biogenic precipitation of realgar (As4S4) in stream sediment. The extent of the phenomenon in Mokrsko is globally unique. A previous study showed the ability of microorganisms to solubilize arsenic from its secondary minerals and to produce realgar precursors, i.e. sulfides and arsenites, by anaerobic respiration. The study also raised questions about the mechanism of realgar precipitation since physicochemical conditions favoring this reaction were never detected despite significant sampling efforts. We chemically and microbiologically analyzed sedimentary profiles to the depth of ca. 120 cm in order to understand the functioning of the biogeochemical system. The profiles comprised both the unsaturated and the saturated zone. We distinguished six different domains representing environments from the surface soil to anoxic sedimnent containing realgar-encrusted wood. An analysis of phylogenetic dissimilarity revealed that microbial communities from the various domains form distinct clusters. This suggests that different conditions prevail in the various domains, and that different biogeochemical processes take place there. Incubation (microcosm) experiments showed that bioprecipitation of realgar can be conducted in vitro. It requires a suppression...
|
|
|
Interactions of metal nanoparticles with microorganisms
Bubáková, Eliška ; Beranová, Jana (advisor) ; Zikánová, Blanka (referee)
This thesis deals with metal nanoparticles and their antibacterial effects. Nanotechnologies have been paid intensive attention both in scientific and public area. Some metal nanoparticles possess provable antibacterial potential. Nowadays, when the growing resistance of pathogenic bacteria represents an important issue, metal nanoparticles could be one of the potential solutions to the problem. Interactions of metal nanoparticles with bacteria have however not yet been fully understood. It is also evident that their effects depend on various physical and biological factors. The cytotoxicity of nanoparticles to eukaryotic organisms has not been explored in depth either. These all are the reasons why the practical use of nanoparticles has still many limitations. This thesis summarizes information available on the topic of bactericidal effects of metal nanoparticles.
|
|
|
Application on nanoparticles in bio-medicine.
Bělinová, Tereza ; Hubálek Kalbáčová, Marie (advisor) ; Beranová, Jana (referee)
During last few years nanoparticles of different origin have been used in biomedicine. Their interactions with cells are however a big point of concern and so further research is needed to be done regarding their properties, internalization into cells and their fate within the cell. All of this is needed for correct selection of proper nanoparticles for bioimaging and also for future use in human medicine. One of the main parts of research is deep understanding of interactions of nanodiamonds and silicon based nanoparticles with cells, because of their highly unique properties (autofluorescence), biocompatibility and in case of silicon nanoparticles also their degradability.
|
guest ::
RSS feed.