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Optimization of cultivation of carotenogenic yeasts on mixed waste substrates
Holub, Jiří ; Mikulíková, Renata (referee) ; Márová, Ivana (advisor)
The master thesis addresses the issue of cultivation of selected strains of carotenogenic yeasts on waste materials of the food industry using a laboratory bioreactor. Carotenogenic yeasts are able to produce highly valuable metabolites during cultivation, which are located predominantly in the lipid part of the cells. Particularly, they are carotenoids, ergosterol, coenzyme Q and fatty acids. The thesis is divided into two main parts, the theoretical part and the practical part. The theoretical part describes individual yeast strains, types of waste materials, produced metabolites and methods of their analysis. The experimental part deals with the processing of waste materials of the food industry, specifically animal fat, whey and spent coffee grounds into the form of substrates usable as nutrition sources for yeast cultivation. Furthermore, cultivations focused on the recovery of the monitored metabolites and their analysis by using HPLC/PDA and GC/FID assemblies were studied as well. The yeast strains Rhodotorula mucilaginosa (CCY 19-4-6), Rhodotorula kratochvilae (CCY 20-2-26), Rhodosporidium toruloides (CCY 062-002-001), Sporidiobolus pararoseus (CCY 19-9-6) a Cystofilobasidium macerans (CCY 10-1-2) were used in this work. As one of the best producing strains Sporidiobolus pararoseus (CCY 19-9-6) was found, which achieved very high productions of carotenoids, coenzyme Q and ergosterol.
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Biotechnological valorization of some food wastes by yeasts
Majdloch, Robert ; Bendová, Agáta (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with biotechnological valorisation of waste substrates, namely waste fat, whey and feathers using carotenogenic yeast. Waste substrates serve as alternative source of nutrients for subsequent cultivation, thanks to this, their utilization and subsequent production of carotenoids, ergosterol, coenzyme Q and lipids occurs. The theoretical part contains the information of selected strains of carotenogenic yeast, such as physiological and growth properties. Their metabolic processes are described together with produced substances. The analytical methods for the determination of substances are described as well. The experimental part focuses on the solution of flask and bioreactor cultivations of four selected strains (Rhodotorula kratochvilovae, Rhodotorula mucilaginosa, Cystofilobasidium macerans a Sporidiobolus pararoseus) on glucose, glycerol and waste substrate at different C/N ratios (13, 25, 50 and 100). Furthermore, individual procedures of waste substrate processing, procedures solving isolation and determination of selected carotenoid substances, which were analysed by HPLC/DAD. Lipid content and their percentage amount were determined by GC/FID. The results of flask and bioreactor cultivations show that the strains have different production at individual C/N ratios. Rhodotorula mucilaginosa strain was selected as the best producer of carotenoids and ergosterol. The highest increases in biomass were achieved by Rhodotorula kratochvilovae strain. Lipid production was the best in the Sporidiobolus pararoseus strain.
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Molecular mechanism of reactive oxygen species production by flavin dehydrogenases of mitochondrial respiratory chain.
Holzerová, Eliška ; Mráček, Tomáš (advisor) ; Kalous, Martin (referee)
The aim of this thesis is to investigate molecular mechanism of reactive oxygen species production by flavin dehydrogenases mitochondrial glycerol-3-phosphate dehydrogenase (mGPDH) and succinate dehydrogenase (SDH). Together, they represent important source of reactive oxygen species in mammalian mitochondria, but the mechanism of electron leak is still poorly understood. Because mechanisms of reactive oxygen species production by other complexes of respiratory chain are better characterized, they can serve as case studies to get insight into mechanisms of reactive oxygen species by flavin dehydrogenases. Relevant knowledge is therefore summarized in the first part of the thesis. To study the production of reactive oxygen species by the isolated flavin dehydrogenases, we used brown adipose tissue mitochondria solubilized by digitonin as a model. Enzyme activity measurements, hydrogen peroxide production studies by Amplex UltraRed fluorescence and luminol luminescence revealed flavin as the most likely source of electron leak in SDH under in vivo conditions, while we propose coenzyme Q binding site as the site of reactive oxygen species production in the case of mGPDH. Distinct mechanism of this production by the two dehydrogenases is also apparent from induction of reactive oxygen species...
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Biotechnological valorization of some food wastes by yeasts
Majdloch, Robert ; Bendová, Agáta (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with biotechnological valorisation of waste substrates, namely waste fat, whey and feathers using carotenogenic yeast. Waste substrates serve as alternative source of nutrients for subsequent cultivation, thanks to this, their utilization and subsequent production of carotenoids, ergosterol, coenzyme Q and lipids occurs. The theoretical part contains the information of selected strains of carotenogenic yeast, such as physiological and growth properties. Their metabolic processes are described together with produced substances. The analytical methods for the determination of substances are described as well. The experimental part focuses on the solution of flask and bioreactor cultivations of four selected strains (Rhodotorula kratochvilovae, Rhodotorula mucilaginosa, Cystofilobasidium macerans a Sporidiobolus pararoseus) on glucose, glycerol and waste substrate at different C/N ratios (13, 25, 50 and 100). Furthermore, individual procedures of waste substrate processing, procedures solving isolation and determination of selected carotenoid substances, which were analysed by HPLC/DAD. Lipid content and their percentage amount were determined by GC/FID. The results of flask and bioreactor cultivations show that the strains have different production at individual C/N ratios. Rhodotorula mucilaginosa strain was selected as the best producer of carotenoids and ergosterol. The highest increases in biomass were achieved by Rhodotorula kratochvilovae strain. Lipid production was the best in the Sporidiobolus pararoseus strain.
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Optimization of cultivation of carotenogenic yeasts on mixed waste substrates
Holub, Jiří ; Mikulíková, Renata (referee) ; Márová, Ivana (advisor)
The master thesis addresses the issue of cultivation of selected strains of carotenogenic yeasts on waste materials of the food industry using a laboratory bioreactor. Carotenogenic yeasts are able to produce highly valuable metabolites during cultivation, which are located predominantly in the lipid part of the cells. Particularly, they are carotenoids, ergosterol, coenzyme Q and fatty acids. The thesis is divided into two main parts, the theoretical part and the practical part. The theoretical part describes individual yeast strains, types of waste materials, produced metabolites and methods of their analysis. The experimental part deals with the processing of waste materials of the food industry, specifically animal fat, whey and spent coffee grounds into the form of substrates usable as nutrition sources for yeast cultivation. Furthermore, cultivations focused on the recovery of the monitored metabolites and their analysis by using HPLC/PDA and GC/FID assemblies were studied as well. The yeast strains Rhodotorula mucilaginosa (CCY 19-4-6), Rhodotorula kratochvilae (CCY 20-2-26), Rhodosporidium toruloides (CCY 062-002-001), Sporidiobolus pararoseus (CCY 19-9-6) a Cystofilobasidium macerans (CCY 10-1-2) were used in this work. As one of the best producing strains Sporidiobolus pararoseus (CCY 19-9-6) was found, which achieved very high productions of carotenoids, coenzyme Q and ergosterol.
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Molecular mechanism of reactive oxygen species production by flavin dehydrogenases of mitochondrial respiratory chain.
Holzerová, Eliška ; Mráček, Tomáš (advisor) ; Kalous, Martin (referee)
The aim of this thesis is to investigate molecular mechanism of reactive oxygen species production by flavin dehydrogenases mitochondrial glycerol-3-phosphate dehydrogenase (mGPDH) and succinate dehydrogenase (SDH). Together, they represent important source of reactive oxygen species in mammalian mitochondria, but the mechanism of electron leak is still poorly understood. Because mechanisms of reactive oxygen species production by other complexes of respiratory chain are better characterized, they can serve as case studies to get insight into mechanisms of reactive oxygen species by flavin dehydrogenases. Relevant knowledge is therefore summarized in the first part of the thesis. To study the production of reactive oxygen species by the isolated flavin dehydrogenases, we used brown adipose tissue mitochondria solubilized by digitonin as a model. Enzyme activity measurements, hydrogen peroxide production studies by Amplex UltraRed fluorescence and luminol luminescence revealed flavin as the most likely source of electron leak in SDH under in vivo conditions, while we propose coenzyme Q binding site as the site of reactive oxygen species production in the case of mGPDH. Distinct mechanism of this production by the two dehydrogenases is also apparent from induction of reactive oxygen species...
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