National Repository of Grey Literature 4 records found  Search took 0.01 seconds. 
Biotechnological production of selected biopolymers employing Haloferax mediterranei
Strečanská, Paulína ; Pernicová, Iva (referee) ; Obruča, Stanislav (advisor)
Aim of this bachelor thesis is to study of production of selected biopolymers, polyhydroxyalkanoates (PHA) and extracellular polysaccharides (EPS) by Haloferax mediterranei. The first part contains theoretical background including properties of biopolymers, advantages and purposes of commercial production, characteristics and positive aspects of cultivation of extreme halophile archaea Haloferax mediterranei. The experimental part is focused on study of effects of concentration of waste substrates, such as proteolytic whey hydrolysate and feather hydrolysate on PHA and EPS production. The effect of medium volume and its correlation with acceess of oxygen on biopolymer production were studied as well. PHA, in particul copolymer P(3HB-co/3HV) was analysed by gas chromatography with FID detection. The content of 3HV in PHA to 15,09 % was achieved using medium which contains 25 % proteolytic whey hydrolysate without glucose supplementation. Medium with 10 % of feather hydrolysate and 10 % of feather hydrolysate with 30 g/l glucose proved to be suitable in volume 50 ml in 250 ml Erlenmeyer flask. Haloferax mediterranei was able to produce biomass and accumulate PHA using protein substrate without need of saccharide supplementation.
Influence of selected parameters on biotechnological production of polyhydroxyalkanoates
Eremka, Libor ; Pekař, Miloslav (referee) ; Obruča, Stanislav (advisor)
The aim of this work is to study microbial production of polyhydroxyalkanoates (PHA). Theoretical part is focused on production of PHA using microoganisms and transgenic plants. Bacterial strain Cupriavidus necator H16 was used for laboratory production of PHA. Various waste oils were used as sole carbon and energy source. Salt of propionic adic and 1-propanol were used as intermediate for 3-hydroxyvalerate monomer (3HV) unit. Incorporation of 3HV to polymer can improve material features of PHA. The major part of experimental work was focused to study influence of aeration (concentration of dissolved oxygen) to bacterial growth, selected metabolic pathways and formation of PHA. Furthermore, influence of aeration to monomer composition of polymer was evaluated. According to experimental conclusion of this work it was approved dependance between aeration and monomer composition of PHA. Moreover, it was approved that higher concentration of oxygen supports bacterial growth and influences PHA content in cells. In addition, NADPH is one of the substrates influencing flux of acetyl-CoA throughout the metabolism; higher intracellular concentration of NADPH inhibits TCA cycle and enhances accumulation of PHA in cells. For this reason, specific enzymatic aktivity of several selected intracelular enzymes were measured, including those enzymes which can generate NADPH.
Biotechnological production of selected biopolymers employing Haloferax mediterranei
Strečanská, Paulína ; Pernicová, Iva (referee) ; Obruča, Stanislav (advisor)
Aim of this bachelor thesis is to study of production of selected biopolymers, polyhydroxyalkanoates (PHA) and extracellular polysaccharides (EPS) by Haloferax mediterranei. The first part contains theoretical background including properties of biopolymers, advantages and purposes of commercial production, characteristics and positive aspects of cultivation of extreme halophile archaea Haloferax mediterranei. The experimental part is focused on study of effects of concentration of waste substrates, such as proteolytic whey hydrolysate and feather hydrolysate on PHA and EPS production. The effect of medium volume and its correlation with acceess of oxygen on biopolymer production were studied as well. PHA, in particul copolymer P(3HB-co/3HV) was analysed by gas chromatography with FID detection. The content of 3HV in PHA to 15,09 % was achieved using medium which contains 25 % proteolytic whey hydrolysate without glucose supplementation. Medium with 10 % of feather hydrolysate and 10 % of feather hydrolysate with 30 g/l glucose proved to be suitable in volume 50 ml in 250 ml Erlenmeyer flask. Haloferax mediterranei was able to produce biomass and accumulate PHA using protein substrate without need of saccharide supplementation.
Influence of selected parameters on biotechnological production of polyhydroxyalkanoates
Eremka, Libor ; Pekař, Miloslav (referee) ; Obruča, Stanislav (advisor)
The aim of this work is to study microbial production of polyhydroxyalkanoates (PHA). Theoretical part is focused on production of PHA using microoganisms and transgenic plants. Bacterial strain Cupriavidus necator H16 was used for laboratory production of PHA. Various waste oils were used as sole carbon and energy source. Salt of propionic adic and 1-propanol were used as intermediate for 3-hydroxyvalerate monomer (3HV) unit. Incorporation of 3HV to polymer can improve material features of PHA. The major part of experimental work was focused to study influence of aeration (concentration of dissolved oxygen) to bacterial growth, selected metabolic pathways and formation of PHA. Furthermore, influence of aeration to monomer composition of polymer was evaluated. According to experimental conclusion of this work it was approved dependance between aeration and monomer composition of PHA. Moreover, it was approved that higher concentration of oxygen supports bacterial growth and influences PHA content in cells. In addition, NADPH is one of the substrates influencing flux of acetyl-CoA throughout the metabolism; higher intracellular concentration of NADPH inhibits TCA cycle and enhances accumulation of PHA in cells. For this reason, specific enzymatic aktivity of several selected intracelular enzymes were measured, including those enzymes which can generate NADPH.

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