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Construction and characterization of recombinant systems for stress response analysis in pollutant-degrading rhodococci
Křenková, Lucie ; Štěpánek, Václav (advisor) ; Marešová, Helena (referee)
Genus Rhodococcus is represented by Gram-positive, mycolate-containing non- sporulating actinobacteria that excel in their ability to withstand effects of various physical and chemical stressors. Their enormous metabolic capacity allows them to efficiently degrade a wide range of toxic compounds. To benefit from these capabilities, it is essential to know the molecular basis of their response to the stresses, the regulation of which is primarily controlled by σ factors of RNA polymerase. These σ factors are still poorly described in rhodococci. This thesis aims to explore the potential of Rhodococcus erythropolis CCM2595 as a model organism for studying stress responses in rhodococci. R. erythropolis ΔsigH mutant and single-plasmid strains have been constructed which allow studying promoter activities of genes responding to osmotic, heat, and oxidative stress by measurement of GFP fluorescence intensity, in the cells of R. erythropolis. Further, homologous two- plasmid strains, which support induced overproduction of s factors, were also constructed. Comparison with analogous Corynebacterium glutamicum host-based systems showed that the use of rhodococci themselves as hosts for plasmid systems is still very limited, probably due to the plasmid instability in rhodococcal cells. Thus, for routine...
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Study of the interaction between fungus Pleurotus ostreatus and bacterial cultures on the abiotic surfaces - morphological, biochemical and proteomic analysis
Kozická, Barbora ; Petráčková, Denisa (advisor) ; Konopásek, Ivo (referee)
Ligninolytic fungi are well known for their ability to degrade a wide range of xenobiotics contaminating the environment, including synthetic industrial dyes. In this work Pleurotus ostreatus was used for decolorization of a synthetic textile dye Remazol Brilliant Blue R (RBBR). To set up a model fungal "fixed-bed" bioreactor the fungus was immobilized on a polyurethane foam and artificially contaminated with a model bacterium Rhodococcus erythropolis. The development of bacterial contamination can be expected during a real application of fungal bio filters in wastewater treatment. The main aim of the work was to study interspecies interactions in the model bioreactors during the dye decolorization. Ligninolytic enzyme activities were followed in the bioreactor cultures as markers of fungal biodegradation ability. In contrast to the controls, no bacterial growth was observed in the P. ostreatus bioreactor culture liquid. The results showed that fungal laccase, pH of the culture liquid, and glucose consumption by the fungus had no effect on the bacterial growth. However, 4*105 - 1,3*106 CFU/ml of R. erythropolis was detected to be associated with the fungal solid support. The presence of these bacteria had no effect on the decolorization performance of the bioreactors. Dye decolorization efficiency...
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Study of the interaction between fungus Pleurotus ostreatus and bacterial cultures on the abiotic surfaces - morphological, biochemical and proteomic analysis
Kozická, Barbora ; Petráčková, Denisa (advisor) ; Konopásek, Ivo (referee)
Ligninolytic fungi are well known for their ability to degrade a wide range of xenobiotics contaminating the environment, including synthetic industrial dyes. In this work Pleurotus ostreatus was used for decolorization of a synthetic textile dye Remazol Brilliant Blue R (RBBR). To set up a model fungal "fixed-bed" bioreactor the fungus was immobilized on a polyurethane foam and artificially contaminated with a model bacterium Rhodococcus erythropolis. The development of bacterial contamination can be expected during a real application of fungal bio filters in wastewater treatment. The main aim of the work was to study interspecies interactions in the model bioreactors during the dye decolorization. Ligninolytic enzyme activities were followed in the bioreactor cultures as markers of fungal biodegradation ability. In contrast to the controls, no bacterial growth was observed in the P. ostreatus bioreactor culture liquid. The results showed that fungal laccase, pH of the culture liquid, and glucose consumption by the fungus had no effect on the bacterial growth. However, 4*105 - 1,3*106 CFU/ml of R. erythropolis was detected to be associated with the fungal solid support. The presence of these bacteria had no effect on the decolorization performance of the bioreactors. Dye decolorization efficiency...
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Biological treatment expertise of sewage water rising from production od DPG (diphenylguanidine).
VEPŘEKOVÁ, Tereza
The main goal of this thesis is to expertise biological treatment of sewage water rising from production of DPG (diphenylguanidine). The theoretical part is focused on the water and means of sewage disposal. There is shortly described mechanism of physical, chemical, biological and combinated methods of sewage disposal. In practical part of this thesis, focused on expertising degradation of DPG and aniline was chosen high performance liquid chromatography (HPLC) technique, which made it possible to determined their biodegradation abilities. The next component of this thesis are sideline products determination, phenylurea especially. This thesis is focused on monitoring of biofilm´s character and the activity of Rhodococcus erythropolis bacterial culture, used in biodegradation of DPG in chemical-biological wastewater treatment plant, LZD a.s.
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