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Study of red yeast metabolism on molecular level
Roubalová, Monika ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
This master thesis is focused on the molecular characterization of the eight red yeasts species. For molecular characterisation, the most variable rDNA regions ITS1, 5,8S ITS2 and the region encoding the large ribosomal subunit (26S) were amplified. This long region of the yeasts DNA was sequenced and compared by NCBI database for identification. The red yeasts identification was confirmed by data from DGGE method. Another aim of this thesis was to select the best yeasts producer of carotenoids and triacylglycerols. Rhodosporidium toruloides was found as the best producer and, thus, this strain was subjected to random mutagenesis by UV irradiation. The results of the production of metabolites by R. toruloides were compared with mutant strains, which were also adapted to the glycerol and waste whey substrates. The mutant strain G33 was found as the best producer of total carotenoids with a yield of 7.14 mg.g-1 of biomass. The highest production of ergosterol was demonstrated by the mutant strain Y34, the ergosterol yield was 47.72 mg.g-1 of biomass. The wild type of R. toruloides was able to produce the highest amount of both carotene (2.42 mg.g-1 of biomass) and TAG (76.32 mg.g-1 of biomass) on glucose medium.
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Comparison of growth and productivity of autotrophic algae and red yeasts
Kouřilová, Xenie ; Rapta, Marek (referee) ; Márová, Ivana (advisor)
The submitted bachelor thesis focuses on the comparison of growth and productivity of red yeasts Rhodotorula aurantiaca and Xanthophyllomyces dendrorhous and autotrophic algae Chlamydomonas reinhardtii and Chlorella vulgaris under different physical conditions. The theoretical part contains the characteristics of selected micro-organisms, stress factors caused by temperature, radiation, combination of aeration and radiation and osmotic stress. Furthermore, knowledge on metabolites and the possibilities of their analysis are mentioned. Physical stresses, namely 2%, 3%, 4% and 5% solution of sodium chloride, intense radiation, absence of lighting, 8°C and 30°C, were applied to selected strains in cultivation. Under these conditions, changes in production of carotenoids, fatty acids, ergosterol, ubiquinone and proteins were being observed. A significant inhibitive effect on all the above mentioned micro-organisms was brought about by the use of 5% solution NaCl. The highest production of metabolites with X. dendrorhous was discovered when 4% solution of NaCl was used. R. aurantiaca demonstrated higher substance utilization at 30°C. For the selected algae strains were the used stresses lethal. Within the cultivation process, the possibilities of co-cultivation of yeasts and algae were also tested, which will be the subject of further studies.
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Characterization of individual phases of cultivation of red yeasts
Valentová, Lucie ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with the problematic of metabolic activity and morphology of several biotechnologically significant red yeasts - Rhodotorula glutinis, Sporobolomyces shibatanus and Phaffia rhodozyma during the cultivation time. These yeasts were cultivated on glucose medium, during the cultivation samples were taken for the analysis of produced metabolites. The amount of -carotene, astaxanthin, coenzyme Q and ergosterol were monitored. The amount of biosynthesised lipids and fatty acid profile was also investigated. HPLC/PDA and GC/FID were used for the analysis of these metabolites. Yeasts were cultivated 56 hours (they reached early stationary phase). The highest production of carotenoid pigments showed Phaffia rhodozyma (1856.58 g/g), 42 % of this amount represents -carotene. The highest lipids biosynthesis efficiency was reached by Rhodotorula glutinis. To study the inner structure of yeast cells the Fluorescence Life-time Imaging was used, the Autofluorescence of carotenoids and fluorescence of lipid bodies induced by lipophilic dye Nile red was observed. This method is very useful for imaging cell inner structure (membranes, some kinds of organelles). The changes that the cell undergoes during its evolution could be quantified too. The relationship between the level of carotenoid concentration, membrane rigidity and metabolic shift was found.
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Characterization of individual phases of cultivation of red yeasts
Valentová, Lucie ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with the problematic of metabolic activity and morphology of several biotechnologically significant red yeasts - Rhodotorula glutinis, Sporobolomyces shibatanus and Phaffia rhodozyma during the cultivation time. These yeasts were cultivated on glucose medium, during the cultivation samples were taken for the analysis of produced metabolites. The amount of -carotene, astaxanthin, coenzyme Q and ergosterol were monitored. The amount of biosynthesised lipids and fatty acid profile was also investigated. HPLC/PDA and GC/FID were used for the analysis of these metabolites. Yeasts were cultivated 56 hours (they reached early stationary phase). The highest production of carotenoid pigments showed Phaffia rhodozyma (1856.58 g/g), 42 % of this amount represents -carotene. The highest lipids biosynthesis efficiency was reached by Rhodotorula glutinis. To study the inner structure of yeast cells the Fluorescence Life-time Imaging was used, the Autofluorescence of carotenoids and fluorescence of lipid bodies induced by lipophilic dye Nile red was observed. This method is very useful for imaging cell inner structure (membranes, some kinds of organelles). The changes that the cell undergoes during its evolution could be quantified too. The relationship between the level of carotenoid concentration, membrane rigidity and metabolic shift was found.
|
|
|
Study of red yeast metabolism on molecular level
Roubalová, Monika ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
This master thesis is focused on the molecular characterization of the eight red yeasts species. For molecular characterisation, the most variable rDNA regions ITS1, 5,8S ITS2 and the region encoding the large ribosomal subunit (26S) were amplified. This long region of the yeasts DNA was sequenced and compared by NCBI database for identification. The red yeasts identification was confirmed by data from DGGE method. Another aim of this thesis was to select the best yeasts producer of carotenoids and triacylglycerols. Rhodosporidium toruloides was found as the best producer and, thus, this strain was subjected to random mutagenesis by UV irradiation. The results of the production of metabolites by R. toruloides were compared with mutant strains, which were also adapted to the glycerol and waste whey substrates. The mutant strain G33 was found as the best producer of total carotenoids with a yield of 7.14 mg.g-1 of biomass. The highest production of ergosterol was demonstrated by the mutant strain Y34, the ergosterol yield was 47.72 mg.g-1 of biomass. The wild type of R. toruloides was able to produce the highest amount of both carotene (2.42 mg.g-1 of biomass) and TAG (76.32 mg.g-1 of biomass) on glucose medium.
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|
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Comparison of growth and productivity of autotrophic algae and red yeasts
Kouřilová, Xenie ; Rapta, Marek (referee) ; Márová, Ivana (advisor)
The submitted bachelor thesis focuses on the comparison of growth and productivity of red yeasts Rhodotorula aurantiaca and Xanthophyllomyces dendrorhous and autotrophic algae Chlamydomonas reinhardtii and Chlorella vulgaris under different physical conditions. The theoretical part contains the characteristics of selected micro-organisms, stress factors caused by temperature, radiation, combination of aeration and radiation and osmotic stress. Furthermore, knowledge on metabolites and the possibilities of their analysis are mentioned. Physical stresses, namely 2%, 3%, 4% and 5% solution of sodium chloride, intense radiation, absence of lighting, 8°C and 30°C, were applied to selected strains in cultivation. Under these conditions, changes in production of carotenoids, fatty acids, ergosterol, ubiquinone and proteins were being observed. A significant inhibitive effect on all the above mentioned micro-organisms was brought about by the use of 5% solution NaCl. The highest production of metabolites with X. dendrorhous was discovered when 4% solution of NaCl was used. R. aurantiaca demonstrated higher substance utilization at 30°C. For the selected algae strains were the used stresses lethal. Within the cultivation process, the possibilities of co-cultivation of yeasts and algae were also tested, which will be the subject of further studies.
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