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Enzymes of Candida tropicalis yeast biodegrading phenol
Koubková, Zuzana ; Stiborová, Marie (advisor) ; Turek, Michal (referee)
Effluents of industrial wastewaters from oil refineries, paper mills, dyes, ceramic factories, resins, textiles and plastic contain high concentrations of aromatic compounds, which are toxic to organisms. Degradation of these compounds to tolerant limits before releasing them into the environment is an urgent requirement. Candida tropicalis yeast is an important representative of eucaryotic microorganisms that are able to utilize phenol. During the first phase of phenol biodegradation, cytoplasmatic NADPH-dependent phenol hydroxylase of C. tropicatis oxidizes phenol to catechol. Catechol is in the second phase of biodegradative process oxidized to cis,cis-muconic acid by the reaction catalyzed with catechol-1,2-dioxygenase. In this diploma thesis we investigated the effect of the heavy metal ions on NADPH-dependent phenol hydroxylase and catechol-1,2-dioxygenase of C. tropicalis. Phenol hydroxylase was inhibited by Cu2+ and Pb2+ ions. Catechol dioxygenase was inhibited by all substances containing heavy metal ions (Fe2+ , Mn2+ , Cd2+ , Cu2+ and Pb2+ ), which were tested in this work. The most effective inhibition was produced by Pb2+ followed by Mn2+ , Cd2+ Fe2+ and Cu2+ ions. The higher sensitivity of catechol-1,2-dioxygenase to heavy metal ions might follow from the presence of histidine residue...
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Trends in payment systems
TUREK, Michal
The aim of this thesis, Trends in Payment System, is to describe and map out the forms of modern payment methods. The theoretical part deals with the evolution and current trends in modern payment methods, basic description of relevant technologies, hardware development, and issues connected with the security of the used methods and services. The practical part analyzes the payment methods used in the Czech Republic and the extent of their use among Czech citizens. The data used for the analysis were collected in a survey by questionnaire containing 17 questions. The answers from 947 respondents were processed to create the profile of a Czech user using the stated payment methods. The data obtained in the practical part also served as the basis for a comparison of the practical use of new payment methods by Czech citizens and by the citizens of a given developed world economy, in this case, the United States of America. The obtained data and their comparison with a study published in the United States ("2014 Consumer Payments Study" by TSYS?) provide evidence of a high standard of the Czech user in the area of modern technologies, and it can be stated that in the environment of new technologies and payment methods, the Czech Republic bears comparison with the world's most advanced countries.
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Enzymes of Candida tropicalis yeast biodegrading phenol
Koubková, Zuzana ; Stiborová, Marie (advisor) ; Turek, Michal (referee)
Effluents of industrial wastewaters from oil refineries, paper mills, dyes, ceramic factories, resins, textiles and plastic contain high concentrations of aromatic compounds, which are toxic to organisms. Degradation of these compounds to tolerant limits before releasing them into the environment is an urgent requirement. Candida tropicalis yeast is an important representative of eucaryotic microorganisms that are able to utilize phenol. During the first phase of phenol biodegradation, cytoplasmatic NADPH-dependent phenol hydroxylase of C. tropicatis oxidizes phenol to catechol. Catechol is in the second phase of biodegradative process oxidized to cis,cis-muconic acid by the reaction catalyzed with catechol-1,2-dioxygenase. In this diploma thesis we investigated the effect of the heavy metal ions on NADPH-dependent phenol hydroxylase and catechol-1,2-dioxygenase of C. tropicalis. Phenol hydroxylase was inhibited by Cu2+ and Pb2+ ions. Catechol dioxygenase was inhibited by all substances containing heavy metal ions (Fe2+ , Mn2+ , Cd2+ , Cu2+ and Pb2+ ), which were tested in this work. The most effective inhibition was produced by Pb2+ followed by Mn2+ , Cd2+ Fe2+ and Cu2+ ions. The higher sensitivity of catechol-1,2-dioxygenase to heavy metal ions might follow from the presence of histidine residue...
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