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Stanovení enzymových aktivit v kompostu
Pernicová, Iva ; doc.Mgr.Pavlína Pelcová, Ph.D. (oponent) ; Voběrková, Stanislava (vedoucí práce)
Tato bakalářská práce se zabývá stanovením enzymových aktivit v kompostu a posuzuje jejich změny v průběhu kompostování. Změny aktivity jednotlivých enzymů slouží jako ukazatele činnosti mikroorganismů, které se v kompostu nacházejí. V praktické části práce byly stanoveny změny aktivity proteáz, celuláz, lipáz, dehydrogenáz a ureáz během 21 dnů kompostování za laboratorních podmínek. Sledována byla také změna pH. Změny hodnot pH a všech aktivit enzymů kromě ureáz vykazovaly v prvním týdnu stejný trend související s využíváním dostupných substrátů. Změny aktivit klíčových enzymů v kompostu za laboratorních podmínek byly srovnány se změnami aktivit v kompostu za reálných podmínek, což je ukazatelem rozdílného průběhu kompostování za daných podmínek.
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Biocatalysts based on lipases, their immobilization and characterization
Bančáková, Anna ; Voběrková, Stanislava (oponent) ; Hermanová, Soňa (vedoucí práce)
The thesis deals with the issue of immobilized enzymes. In the theoretical part, principal and novel methods of immobilization and types of carriers are reviewed together with practical applications of immobilized enzymes. Particularly, recent utilization of immobilized enzymes in a variety of industries such as food industry, medicine, chemical analysis, bioremediation, and biodiesel production is summarized. Different methodologies including adsorption, entrapment, covalent binding and cross-linking are discussed from the viewpoint of their dis/advantages resulting from the extent and the character of binding and the maintenance of enzyme activity. Among new carriers, the research work done on the utilization of graphene as a novel carrier for enzyme immobilization is particularly reported. In the experimental part, immobilization of commercial preparation of lipase (RA) isolated from microscopic fungi Rhizopus arrhizus was performed by adsorption on polyethylene terephthalate as a carrier. The basic parameters as lipolytic activity, temperature optimum, pH optimum and thermal stability of both soluble as well as immobilized enzyme were determined spectrophotometrically using p-nitrophenyl-laurate (pNPL) as a substrate. Both the soluble and immobilized lipase showed maximum activity at pH 7.2 and a decrease in activity was observed above pH 8 or below pH 6.5. The dependence of activity on pH of reaction medium was more pronounced in the case of immobilized form of enzyme. The soluble and immobilized lipases exhibited maximum activity at a temperature of approximately 30 °C. A drop in activity values was observed when the temperature was increased up to 50 °C and above this temperature the stability of the soluble lipase sharply decreased. On the contrary, thermal stability of immobilized RA lipase was significantly improved. Immobilized form of enzyme possesses activity 3.7 % in comparison to the soluble form.
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Enzyme Hydrolysis of Triglycerides in Segmented Flow Microdevices
Čech, J. ; Slouka, Z. ; Schrott, W. ; Přibyl, M. ; Kuncová, Gabriela
In this study, we deal with a microcapillary/microchannel reaction system for enzyme hydrolysis of triglycerides. The microdevices were fabricated by a combination of traditional techniques – UV photolithography, micromachining, hot assembling, casting and UV/O3 treatment. The water-oil emulsion was generated in a plexiglass microchip with an X-cros microchannel arrangement. Both the oil and water were pumped into the microchip by a precise syringe pumps. The oil phase was introduced into the central microchannel whereas water into the two side channels.
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