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Production, Characterization and Utilization of the Biomass from Various Sources
Gojkovic, Živan ; Vávrová, Milada (oponent) ; Čertík, Milan (oponent) ; Márová, Ivana (vedoucí práce)
Biomass management is one of the most important issues in modern natural science as it is the basic category which spans through various disciplines of biotechnology. Whether animal, plant or microbial by its origin, biomass presents a vast source of food components, fine chemicals and bioactive molecules, which extraction, characterization and formulation can result in interesting new products destined for human consumption or as new materials in biomedicine. In the scope of this work, two natural biomass types were investigated – chicken skin as a source of collagen type I, and green microalga Chlorella sorokiniana biomass enriched in selenomethionine (SeMet). Chicken skin is a good alternative to traditional sources of collagen such as pork, bovine and carp that have some limitations. In the first part of this thesis, collagen type I from chicken skin was isolated, identified and characterized and molecular properties were compared to collagen from other animal skins. New methods (viscosimetry and ultrasonic spectroscopy) for molecular characterization of collagen were used. By ultrasonic attenuation, it has been determined that disaggregation and liquefaction phase starts at 40 °C in bovine collagen, whereas in chicken collagen starts at 50 °C. Using viscosimetry technique, denaturation temperature was found to be 50 °C, which is 10 °C higher than that obtained with bovine tendon collagen, confirming higher thermal stability of chicken skin collagen, probably because lysine levels in chicken collagen are two times higher than in bovine. Based on obtained results it could be concluded that due to its higher thermal stability and amino acid composition, chicken skin could be used as an excellent alternative source of collagen. The second phase of the thesis focused on the enrichment of green microalga C. sorokiniana biomass in SeMet by exposing cultures to selenate Se (+VI) during batch and continuous cultivation, and it was performed at the laboratory of Biotechnology of Algae from the Faculty of Experimental Sciences at the University of Huelva in Spain. Effect of selenate on viability, cell morphology and SeMet accumulation of the microalga C. sorokiniana grown in batch conditions was studied. Growth rate of cultures exposed to a sub-lethal 40 mgL1 (212 M) of Se decreased about 25 % compared to control. EC50 of 45 mgL1 (238.2 M) was determined for selenate. Ultrastructural studies with electronic microscope revealed cellular alterations. Electrophoresis of Se-exposed cell proteins suggests that selenate affects expression of the Rubisco gene. Microalga was able to accumulate up to 140 mgkg-1 of SeMet in 120 h of cultivation. The second type of microalgae experiments focused on the enrichment of C. sorokiniana in SeMet, grown in continuous conditions in a 2.2 L photobioreactor, in a medium supplemented with selenate concentrations ranging from 5 to 50 mgL-1. Continuous cultivation at several dilution rates was performed at 40 mgL-1 selenate obtaining a maximum of 246 gL-1day-1 of SeMet. Results suggest that an efficient batch and continuous cultivation of C. sorokiniana for the production of biomass enriched in the high value amino acid SeMet, at laboratory scale is feasible by carefully selecting sub-lethal selenate concentrations in culture medium as well as the culture dilution rates.
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Studium přípravků do odlučovačů tuků
Gojkovic, Živan ; Ing.Dana Flodrová, Ph.D. (oponent) ; Omelková, Jiřina (vedoucí práce)
Diplomová práce byla zaměřena na testování komerčního přípravku do odlučovačů tuků. Cílem práce bylo dokázat schopnost přítomných mikroorganismu v přípravku, produkovat lipázy, které působí na různé lipidové substráty. K analýze bylo použito celkem 4 druhů rostlinných olejů a 2 druhů živočišných tuků. Pro submerzní kultivaci bylo použito speciálně připravené médium, do kterého následně byl přidáván určitý druh tuků nebo oleje. U všech substrátů byly stanoveny číslo zmýdelnění, číslo kyselosti, esterové a peroxidové číslo. Aktivita enzymu a narůst biomasy byly měřeny spektrofotometrický a degradace lipidů byla měřena titračně. Studie ukázala, že testované mikroorganizmy z přípravku utilizují všechny lipidové substráty.
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Production, Characterization and Utilization of the Biomass from Various Sources
Gojkovic, Živan ; Vávrová, Milada (oponent) ; Čertík, Milan (oponent) ; Márová, Ivana (vedoucí práce)
Biomass management is one of the most important issues in modern natural science as it is the basic category which spans through various disciplines of biotechnology. Whether animal, plant or microbial by its origin, biomass presents a vast source of food components, fine chemicals and bioactive molecules, which extraction, characterization and formulation can result in interesting new products destined for human consumption or as new materials in biomedicine. In the scope of this work, two natural biomass types were investigated – chicken skin as a source of collagen type I, and green microalga Chlorella sorokiniana biomass enriched in selenomethionine (SeMet). Chicken skin is a good alternative to traditional sources of collagen such as pork, bovine and carp that have some limitations. In the first part of this thesis, collagen type I from chicken skin was isolated, identified and characterized and molecular properties were compared to collagen from other animal skins. New methods (viscosimetry and ultrasonic spectroscopy) for molecular characterization of collagen were used. By ultrasonic attenuation, it has been determined that disaggregation and liquefaction phase starts at 40 °C in bovine collagen, whereas in chicken collagen starts at 50 °C. Using viscosimetry technique, denaturation temperature was found to be 50 °C, which is 10 °C higher than that obtained with bovine tendon collagen, confirming higher thermal stability of chicken skin collagen, probably because lysine levels in chicken collagen are two times higher than in bovine. Based on obtained results it could be concluded that due to its higher thermal stability and amino acid composition, chicken skin could be used as an excellent alternative source of collagen. The second phase of the thesis focused on the enrichment of green microalga C. sorokiniana biomass in SeMet by exposing cultures to selenate Se (+VI) during batch and continuous cultivation, and it was performed at the laboratory of Biotechnology of Algae from the Faculty of Experimental Sciences at the University of Huelva in Spain. Effect of selenate on viability, cell morphology and SeMet accumulation of the microalga C. sorokiniana grown in batch conditions was studied. Growth rate of cultures exposed to a sub-lethal 40 mgL1 (212 M) of Se decreased about 25 % compared to control. EC50 of 45 mgL1 (238.2 M) was determined for selenate. Ultrastructural studies with electronic microscope revealed cellular alterations. Electrophoresis of Se-exposed cell proteins suggests that selenate affects expression of the Rubisco gene. Microalga was able to accumulate up to 140 mgkg-1 of SeMet in 120 h of cultivation. The second type of microalgae experiments focused on the enrichment of C. sorokiniana in SeMet, grown in continuous conditions in a 2.2 L photobioreactor, in a medium supplemented with selenate concentrations ranging from 5 to 50 mgL-1. Continuous cultivation at several dilution rates was performed at 40 mgL-1 selenate obtaining a maximum of 246 gL-1day-1 of SeMet. Results suggest that an efficient batch and continuous cultivation of C. sorokiniana for the production of biomass enriched in the high value amino acid SeMet, at laboratory scale is feasible by carefully selecting sub-lethal selenate concentrations in culture medium as well as the culture dilution rates.
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Studium přípravků do odlučovačů tuků
Gojkovic, Živan ; Ing.Dana Flodrová, Ph.D. (oponent) ; Omelková, Jiřina (vedoucí práce)
Diplomová práce byla zaměřena na testování komerčního přípravku do odlučovačů tuků. Cílem práce bylo dokázat schopnost přítomných mikroorganismu v přípravku, produkovat lipázy, které působí na různé lipidové substráty. K analýze bylo použito celkem 4 druhů rostlinných olejů a 2 druhů živočišných tuků. Pro submerzní kultivaci bylo použito speciálně připravené médium, do kterého následně byl přidáván určitý druh tuků nebo oleje. U všech substrátů byly stanoveny číslo zmýdelnění, číslo kyselosti, esterové a peroxidové číslo. Aktivita enzymu a narůst biomasy byly měřeny spektrofotometrický a degradace lipidů byla měřena titračně. Studie ukázala, že testované mikroorganizmy z přípravku utilizují všechny lipidové substráty.
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