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Acetic acid as a side product of metabolism of PHA producing bacteria
Ryšavá, Lenka ; Obručová,, Hana (referee) ; Obruča, Stanislav (advisor)
The Bachelor´s thesis deals with experimental study production of acetic acid as a side product of metabolism of PHA producing bacteria. Experimental part of work deals with the impact of used substrate on the biomass growth, PHA production and the formation of organic acids in strains that can potentially find their application in industrial production of PHA – Cupriavidus necator H16, Burkholderia sacchari, Burkholderia cepacia. The highest yields of organic acid have been reached on Burkholderia sacchari when cultivated on mineral medium with glucose. The last part of the thesis is focused on determining the viability of micro organisms using flow cytometry where bacteria Cupriavidus necator H16, Burkholderia sacchari, Burkholderia cepacia were exposed to selected stress factors.
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Study on PHA accumulation by cyanobacteria
Pacasová, Viktorie-Alexandra ; Slaninová, Eva (referee) ; Obruča, Stanislav (advisor)
This bachelor thesis was focused on studying the influence of selected stress factors on PHB production in strains of cyanobacteria Synechocystis sp. PCC 6803 and Synechocystis salina CCALA 192. Cyanobacterial stains were cultivated in multicultivator and as a stress factor an increased salt (sodium chloride) as well as a mixture of acetate and -butyrolactone was selected. The PHB content in cyanobacteria was determined by gas chromatography. In addition, the content and presence of pigments in cyanobacteria strains was determined by pigment extraction as well as using direct spectroscopy of whole cells. When cultivated with an increased salinity, the hypothesis of an increased PHB production was not confirmed most likely due to and overstressing the Synechocystis salina CCALA 192 cultures with increased salt content, constant illumination of multicultivator and by nitrogen limitation due to the used medium. When cultivated with the mixture of acetate and -butyrolactone the stains were analysed in the same way as in the cultivation with an increased salinity. In this case, the presence of 3-hydroxybutyrate and 4-hydroxybutyrate copolymer was determined in the stain cultivated with the mixture of acetate and -butyrolactone. During this cultivation, a positive effect of initial concentration of cells in the cyanobacterial cultures combined with continuous illumination and the type of nitrogen-limiting type of medium on the growth rate of selected stains was observed.
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Study on PHA accumulation by cyanobacteria
Pacasová, Viktorie-Alexandra ; Slaninová, Eva (referee) ; Obruča, Stanislav (advisor)
This bachelor thesis was focused on studying the influence of selected stress factors on PHB production in strains of cyanobacteria Synechocystis sp. PCC 6803 and Synechocystis salina CCALA 192. Cyanobacterial stains were cultivated in multicultivator and as a stress factor an increased salt (sodium chloride) as well as a mixture of acetate and -butyrolactone was selected. The PHB content in cyanobacteria was determined by gas chromatography. In addition, the content and presence of pigments in cyanobacteria strains was determined by pigment extraction as well as using direct spectroscopy of whole cells. When cultivated with an increased salinity, the hypothesis of an increased PHB production was not confirmed most likely due to and overstressing the Synechocystis salina CCALA 192 cultures with increased salt content, constant illumination of multicultivator and by nitrogen limitation due to the used medium. When cultivated with the mixture of acetate and -butyrolactone the stains were analysed in the same way as in the cultivation with an increased salinity. In this case, the presence of 3-hydroxybutyrate and 4-hydroxybutyrate copolymer was determined in the stain cultivated with the mixture of acetate and -butyrolactone. During this cultivation, a positive effect of initial concentration of cells in the cyanobacterial cultures combined with continuous illumination and the type of nitrogen-limiting type of medium on the growth rate of selected stains was observed.
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Acetic acid as a side product of metabolism of PHA producing bacteria
Ryšavá, Lenka ; Obručová,, Hana (referee) ; Obruča, Stanislav (advisor)
The Bachelor´s thesis deals with experimental study production of acetic acid as a side product of metabolism of PHA producing bacteria. Experimental part of work deals with the impact of used substrate on the biomass growth, PHA production and the formation of organic acids in strains that can potentially find their application in industrial production of PHA – Cupriavidus necator H16, Burkholderia sacchari, Burkholderia cepacia. The highest yields of organic acid have been reached on Burkholderia sacchari when cultivated on mineral medium with glucose. The last part of the thesis is focused on determining the viability of micro organisms using flow cytometry where bacteria Cupriavidus necator H16, Burkholderia sacchari, Burkholderia cepacia were exposed to selected stress factors.
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