|
Characterization of the antibacterial potential of recently synthesized compounds and bacterial communities
Diepoltová, Adéla ; Nachtigal, Petr (advisor) ; Pávková, Ivona (referee) ; Palyzová, Andrea (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Biological and Medical Sciences Candidate: Mgr. Adéla Diepoltová Supervisor: prof. PharmDr. Petr Nachtigal, Ph.D. Consultant: RNDr. Klára Konečná, PhD. Title of Doctoral Thesis: Characterization of the antibacterial potential of recently synthesized compounds and bacterial communities The theoretical part of this dissertation thesis describes the issue of antimicrobial resistance, which represents one of the greatest current challenges to global health. Many different factors contribute to the criticality of this situation. In addition to undeniable human involvement, microbes themselves, such as bacteria from the ESKAPE group, are responsible for this serious problem. Microbes exhibit a variety of resistance mechanisms. The ability to form microbial biofilms is one of them. As a matter of fact, cells present in biofilm are up to 1000 × more resistant compared to their planktonic form. To reveal the most relevant data regarding the process of biofilm formation in vitro, it is essential to use reproducible methods in order to obtain robust biofilms with all their key attributes that represent the adaptive resistance (presence of an extracellular polymeric matrix, the architecture of a matured biofilm, etc.). These attributes are...
|
|
Rutinosidase from Aspergillus niger - analysis of active site and its mutagenesis
Šidáková, Anna ; Bojarová, Pavla (advisor) ; Palyzová, Andrea (referee)
Rutinosidases (α-L-rhamnosyl-β-D-glucosidases) from Aspergillus niger (AnRut) are glycosidases (EC 3.2.1) that catalyze the hydrolysis of the glycosidic bond between the aglycone and the disaccharide residue rutinose. The dual substrate specificity of this enzyme group describes the parallel activity towards the substrates rutin (carrying a rutinosyl disaccharide residue) and isoquercitrin (carrying a glucosyl residue). The active site of AnRut is more complex than that of other glycosidases and is composed of the catalytic amino acids Glu210 and Glu319 in the active-site cleft and a side tunnel. This untraditional structure with distinct interactions in the tunnel and active-site cleft is the probable reason for the enzyme exceptional substrate specificity. Through point or multiple mutations of the enzyme, we can modify its primary and secondary structure, thus causing a significant shift in substrate specificity. The main goal of this thesis is the analysis of three distinct mutant variants of AnRut rutinosidase; their production, purification, and the study of the influence of the mutations on the substrate specificity of the enzymes. All variants were designed based on molecular modeling. The substrate specificity was determined by reactions of the mutant variants with previously unstudied...
|
|
The role of F420-dependent oxidoreductases in actinobacteria
Kekrt, Lukáš ; Kameník, Zdeněk (advisor) ; Palyzová, Andrea (referee)
Deazaflavin F420 is an unusual cofactor involved in oxidoreduction reactions in the cells of some microorganisms. The role of F420/F420H2-dependent oxidoreductases has been extensively described in the case of central archaeal metabolism, particularly those of methanogens. In contrast, our knowledge of these enzymes in actinobacteria is limited. This work focuses on the characterization of selected actinobacterial oxidoreductases from luciferase-like hydride transferase family, which putatively use the F420 cofactor. Specifically, Apd6 biosynthetic proteins and their sequence homologs were studied. Three recombinant proteins were prepared and purified and their enzymatic activity was tested in the presence of F420 and a set of putative substrates by means of in vitro reactions. The reaction products were monitored by liquid chromatography with UV and mass spectrometry detection. Some of the expected reaction products were detected in in vitro reactions, confirming that the proteins were catalytically active. Furthermore, one of the proteins surprisingly exhibited an unusual reaction specificity. Key words: Specialized metabolism, actinobacteria, F420 cofactor, redox reactions, reaction specificity, 4-alkyl-L-proline derivates.
|
|
Determination of distribution of pharmacologically active compounds and their biological degradation during waste water treatment processes
Palyzová, Andrea ; Kyslík, Pavel ; Marešová, Helena
The project is focused on the development of technology for the degradation of persistent active pharmacologically substances (APIs) in wastewater. These substances are biologically active, due to their physicochemical properties often difficult to degrade, their consumption in human and veterinary medicine is difficult to control. By using it alone, even non-metabolized drugs enter the environment. End-user disposal of unused drugs is virtually uncontrollable and is becoming another important source of pollution. APIs are a common nodal point for the main sources of environmental contamination. Unfortunately, in the case of the API series, current WWTP systems are not even capable of capturing, let alone degradation, and are therefore distributed back to the environment via surface waters. The development of persistent APIs degradation technology at the WWTP level is the aim of the project. Its implementation will significantly reduce the level of surface water pollution and thus increase the sustainability of the use of water resources.
|
|
Microbial analysis and identification of organisms in products from young cocco
Palyzová, Andrea ; Marešová, Helena
The collaboration focused on the isolation and identification of bacterial strains in young coconut products, the comparison of their microbial profiles and the monitoring of stability over time. Yoguard and Keefir products contain highly functional probiotic bacteria and probiotic yeasts. The main microorganisms contained in yoghurts and keefires include Lactobacillus, Streptococcus, Enterococcus, Lactococcus, Leuconococcus, Saccharomyces.\nThe main microorganisms contained in yoghurts and keefires include Lactobacillus, Streptococcus, Enterococcus, Lactococcus, Leuconococcus, Saccharomyces.\n\n\n\n\n\n\n\n\n\n\n
|
|
Inhibitory effects of B. velezensis strain on plant pathogens of the genus Xanthomonas
Švecová, Magdaléna ; Palyzová, Andrea (advisor) ; Jelínková, Markéta (referee)
Biological control is a method of applied ecology that uses one organism, or its product, to inhibit another pathogenic organism. This method in plant protection should be more environmentally friendly than commonly used pesticides. The rhizobacterium Bacillus velezensis FZB42, which can suppress the growth of other microorganisms, can be used as a biological control agent. Xanthomonas campestris pv. campestris is a phytopathogen that causes significant losses in agricultural production. This diploma thesis proved an antagonistic effect of the bacterial strain B. velezensis FZB42 on the phytopathogenic bacteria Xanthomonas campestris pv. campestris SU in mixed culture. The study confirmed that the antibiotic effect of B. velezensis strain FZB42 against X. campestris pv. campestris SU in mixed culture depends on the inoculation ratios of both strains. The interaction of the two bacterial strains was characterized by metabolomics analysis, it was confirmed that B. velezensis FZB42 produces four dominant secondary metabolites: lipopeptides surfactin, fengycin, and bacillomycin and siderophore bacillibactin, which show antifungal and antibiotic activity. The inhibitory activity of B. velezensis strain FZB42 was further monitored by SEM analysis, which showed damage to X. campesris pv. campestris SU...
|
|
Characterization of microorganisms with biodegradation potential for sulfonamides
Sedláček, Jan ; Palyzová, Andrea (advisor) ; Mikušová, Gabriela (referee)
Sulfonamides are antibiotics that are frequently used both in human and veterinary medicine. The combinations of abundant use of these antibiotics and their natural resistance to decay leads often to long term persistence in the environment. This accumulation, especially in living organisms, may lead to subsequent toxicosis. Also, presence of these antibiotic in nature poses problems with regard to the spread of genes for antibiotic resistance between potential pathogens. These facts led to an increase interest in studying the sulfonamide biodegradation and subsequent sulfonamide removal from the environment. In this work it was possible to isolate and characterize the microorganism Acinetobacter sp. strain 49. This microorganism was able to biodegrade under right conditions sulfamethoxazole with 80 % efficiency. Sulfamethoxazole is one of the most commonly found sulfonamide in the nature.
|
| |
| |
|
Transfer of technology for production of AEH from Sphingomonas sp
Kyslíková, Eva ; Palyzová, Andrea ; Marešová, Helena ; Štěpánek, Václav ; Zahradník, Jiří ; Bečka, Stanislav ; Dobišová, Marie ; Kyslík, Pavel
Research report on construction of a recombinant production microorganism, the way of its cultivation in stirred bioreactor, overproduction and isolation of AEH and stabilization of AEH as cross linked enzyme agregate
|