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Controlled production of polyhydroxyalcanoates by bacterial strain Ralstonia eutropha using different substrates
Šnajdar, Ondřej ; Duroňová, Kateřina (referee) ; Márová, Ivana (advisor)
This bachelor’s thesis deals with production of polyhydroxyalkanoates (PHA) by bacterial strain Ralstonia eutropha. Production of PHA on different substrates has been studied to lower the costs of feedstock. In theoretical part the review has been done about the most important types of PHA, production strains and possibilities of cultivation of Ralstonia eutropha using different substrates. In practical part there has been studied production of PHA on different vegetable oils, including waste oils from different sources (restaurants, homes, food companies). Incorporation of different precursors for copolymer production control was studied too. The highest yields of poly-3-hydroxybutyrate (P3HB) have been achieved using waste oils. For economical and ecological reasons these oils are very suitable substrates. Using concentration 20 g/l of waste rapeseed oil from university canteen there has been produced 13,32 g/l of biomass containing 58,63% of P3HB in 84th hour of cultivation. The highest yield of PHA in precursors study has been achieved applying 1% propanol in 24th hour of cultivation. The PHA increase has been 97%. This PHA was composed from 91% of 3HB and 9% of 3-hydroxyvalerate.
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Influence of bioplastic biodegradation on soil properties
Stanislavová, Veronika ; Zlámalová Gargošová, Helena (referee) ; Kučerík, Jiří (advisor)
Biodegradabilné polyméry sa na trhu stávajú čoraz populárnejšími, a to najmä v poľnohospodárstve, kde sa vďaka svojim priaznivým vlastnostiam používajú ako nátery a mulčovacie fólie. V tejto štúdii bol skúmaný vplyv poly-3-hydroxybutyrátu (P3HB), vnútrobunkového bakteriálneho polyméru, na rôzne vlastnosti pôdy vrátane fyzikálnych, chemických a biologických parametrov s cieľom posúdiť jeho potenciálne využitie v poľnohospodárstve. Výsledky ukázali, že P3HB mal negatívny vplyv na obsah sušiny v pôde, nadzemnú biomasu a spôsobil mierne zníženie pH pôdy. Okrem toho sa aktivita vybraných enzýmov výrazne zvýšila, keď sa P3HB aplikoval samostatne alebo došlo k ešte väčšiemu nárastu v kombinácií s niektorými pôdnymi doplnkami. Výsledky sa líšili v závislosti od použitého pôdneho doplnku. Účinky boli buď negatívne, neutrálne alebo pozitívne. Na posúdenie miery biodegradácie P3HB, vplyvu P3HB na organickú hmotu a zadržiavanie vody sa použila termogravimetrická analýza. Bolo preukázané, že prítomnosť organických doplnkov ovplyvnila rýchlosť degradácie P3HB a iných organických látok v pôde. Okrem toho aplikácia P3HB do pôdy viedla k inhibícii rastu rastlín (Zea mays L.). Pridanie zmien do pôdy pred aplikáciou P3HB tento účinok zlepšilo len okrajovo. Dospelo sa k záveru, že biodegradácia P3HB podporovala mikrobiálnu aktivitu, čo mohlo v konečnom dôsledku negatívne ovplyvniť dostupnosť esenciálnych živín v pôde. Okrem toho výsledky z termogravimetrickej analýzy naznačujú, že kombinácia P3HB a biouhlia by mohla prispieť k lepšiemu zadržiavania vody v pôde.
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Biotransformation of phenolic compounds by bacterium Schlegelella thermodepolymerans
Opial, Tomáš ; Dvořák,, Pavel (referee) ; Obruča, Stanislav (advisor)
The diploma thesis deals with the optimization of the biotransformation of ferulic acid into sensory active substances and production of P3HB by bacterium Schlegelella thermodepolymerans. Cultivation experiments were performed in a medium with various concentrations of ferulic acid. Four bacterial strains were used for these experiments. Attention was paid to the model strain DSM 15344, in which a bioinformatic analysis of genes encoding enzymes, that catalyzed the biotransformation reactions of ferulic acid was also performed. Ferulic acid metabolites, specifically sensory active substances such as vanillyl alcohol, vanillic acid, vanillin and 4-vinylguaiacol, were measured by HPLC. S. thermodepolymerans DSM 15344 exhibited a very fast utilization of ferulic acid already within 8 hours of cultivation. The highest yields of ferulic acid metabolites were detected between 8 and 24 hours depending on the initial concentration of ferulic acid. The main metabolites of ferulic acid were vanillic acid and vanillyl alcohol. Vanillic acid reached the highest concentration in 16 hours in the presence of ferulic acid at initial concentration of 0.5 g/l. The highest yield of vanillyl alcohol occurred in 8 hours with ferulic acid at initial concentration of 0.75 g/l. In addition to biotransformation to ferulic acid, the amount of produced P3HB was also measured by GC-FID. Schlegelella thermodepolymerans DSM 15344 produced the highest amount of P3HB at 72 h at the lowest initial concentration of ferulic acid (0.25 g/l). Within the bioinformatic analysis, the presence of one fcs gene was confirmed using the available databases and the BLAST tool, but this was not enough to construct the complete metabolic pathway of ferulic acid by the bacterium S. thermodepolymerans DSM 15344.
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Controlled production of polyhydroxyalcanoates by bacterial strain Ralstonia eutropha using different substrates
Šnajdar, Ondřej ; Duroňová, Kateřina (referee) ; Márová, Ivana (advisor)
This bachelor’s thesis deals with production of polyhydroxyalkanoates (PHA) by bacterial strain Ralstonia eutropha. Production of PHA on different substrates has been studied to lower the costs of feedstock. In theoretical part the review has been done about the most important types of PHA, production strains and possibilities of cultivation of Ralstonia eutropha using different substrates. In practical part there has been studied production of PHA on different vegetable oils, including waste oils from different sources (restaurants, homes, food companies). Incorporation of different precursors for copolymer production control was studied too. The highest yields of poly-3-hydroxybutyrate (P3HB) have been achieved using waste oils. For economical and ecological reasons these oils are very suitable substrates. Using concentration 20 g/l of waste rapeseed oil from university canteen there has been produced 13,32 g/l of biomass containing 58,63% of P3HB in 84th hour of cultivation. The highest yield of PHA in precursors study has been achieved applying 1% propanol in 24th hour of cultivation. The PHA increase has been 97%. This PHA was composed from 91% of 3HB and 9% of 3-hydroxyvalerate.
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