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Characterization of extracellular enzymes and other metabolites of carotenogenic yeasts
Těšíková, Karolína ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
Lipases are enzymes catalyzing primarily the hydrolytic cleavage of triacylglycerol bonds. The production of lipolytic enzymes is known in many microorganisms, especially those who are able to utilize a fatty carbon substrate. Some genera of carotenogenic yeasts are characterized by this ability. Carotenogenic yeasts are characterized primarily by the formation of intracellular carotenoids, lipids and lipid-soluble substances. In addition to these metabolites, they may also produce some biosurfactants. This work deals with the production of extracellular lipolytic enzymes and biosurfactants by carotenogenic yeasts Rhodotorula glutinis, Cystofilobasidium macerans, Rhodotorula mucilaginosa and Sporidiobolus pararoseus cultivated mainly on animal waste fat at various C/N ratios (13, 25, 50, 100). Lipase activity was detected in all strains studied. Enzyme activities were measured by spectrophotometric method. Lipase induction has also been observed during cell growth, where several peaks of lipase activity have been reported, suggesting cell-associated lipase and lipase secreted into the environment. Lipase activities have also been found in cultures on glucose and glycerol carbon substrates. Further, the molecular characterization of lipolytic enzymes was performed using polyacrylamide gel electrophoresis. The formation of biosurfactants is to some extent formed by all strains. In particular, the biosurfactants of C. macerans and S. pararoseus yeast have emulsifying and solubilizing properties. Simultaneously with the production of lipase and biosurfactants, the production of characteristic high value added intracellular metabolites in S. pararoseus and R. mucilaginosa was evaluated too.
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Assessment of fatty acids in selected type of cheese
Těšíková, Karolína ; Sůkalová, Kateřina (referee) ; Vítová, Eva (advisor)
This bachelor’s thesis is focused on identification and quantification of free and bound fatty acids in model cheeses of „Moravský bochník“, made at Tomáš Baťa University in Zlín. Theoretical part is dealing with characteristics of lipids and fatty acids. Furthermore, the classification of cheese types and description of their production and composition are discussed. Finally, the gas chromatography is described as a most commonly used method for assessment of fatty acids. The experimental part focuses on comparing the content of free and bound fatty acids in four model cheeses in relation to the use of different microbial cultures. The method according to the ČSN EN ISO 1735:2005 was employed for extraction of lipids from cheese samples. The present fatty acids were identified and quantified by gas chromatography with flame ionization detector after conversion to methylesters using acid-catalysed esterification with a methanolic solution of boron trifluoride. In total, 32 bound and 20 free fatty acids were identified in cheese samples.
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Characterization of extracellular enzymes and other metabolites of carotenogenic yeasts
Těšíková, Karolína ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
Lipases are enzymes catalyzing primarily the hydrolytic cleavage of triacylglycerol bonds. The production of lipolytic enzymes is known in many microorganisms, especially those who are able to utilize a fatty carbon substrate. Some genera of carotenogenic yeasts are characterized by this ability. Carotenogenic yeasts are characterized primarily by the formation of intracellular carotenoids, lipids and lipid-soluble substances. In addition to these metabolites, they may also produce some biosurfactants. This work deals with the production of extracellular lipolytic enzymes and biosurfactants by carotenogenic yeasts Rhodotorula glutinis, Cystofilobasidium macerans, Rhodotorula mucilaginosa and Sporidiobolus pararoseus cultivated mainly on animal waste fat at various C/N ratios (13, 25, 50, 100). Lipase activity was detected in all strains studied. Enzyme activities were measured by spectrophotometric method. Lipase induction has also been observed during cell growth, where several peaks of lipase activity have been reported, suggesting cell-associated lipase and lipase secreted into the environment. Lipase activities have also been found in cultures on glucose and glycerol carbon substrates. Further, the molecular characterization of lipolytic enzymes was performed using polyacrylamide gel electrophoresis. The formation of biosurfactants is to some extent formed by all strains. In particular, the biosurfactants of C. macerans and S. pararoseus yeast have emulsifying and solubilizing properties. Simultaneously with the production of lipase and biosurfactants, the production of characteristic high value added intracellular metabolites in S. pararoseus and R. mucilaginosa was evaluated too.
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Assessment of fatty acids in selected type of cheese
Těšíková, Karolína ; Sůkalová, Kateřina (referee) ; Vítová, Eva (advisor)
This bachelor’s thesis is focused on identification and quantification of free and bound fatty acids in model cheeses of „Moravský bochník“, made at Tomáš Baťa University in Zlín. Theoretical part is dealing with characteristics of lipids and fatty acids. Furthermore, the classification of cheese types and description of their production and composition are discussed. Finally, the gas chromatography is described as a most commonly used method for assessment of fatty acids. The experimental part focuses on comparing the content of free and bound fatty acids in four model cheeses in relation to the use of different microbial cultures. The method according to the ČSN EN ISO 1735:2005 was employed for extraction of lipids from cheese samples. The present fatty acids were identified and quantified by gas chromatography with flame ionization detector after conversion to methylesters using acid-catalysed esterification with a methanolic solution of boron trifluoride. In total, 32 bound and 20 free fatty acids were identified in cheese samples.
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