Selection and optimization of acetic acid bacteria for d-gluconic acid production

Identificador:  TDX:2484

Handle: https://hdl.handle.net/20.500.11797/TDX2484

Autors:  Sainz Perez, Florencia

Resum:
In this PhD thesis, the selection of Acetic acid bacteria (AAB) was carried out to perform a selective fermentation of D-glucose into D-gluconic acid, without consuming fructose. Three AAB strains were selected, two of them belonging to the Gluconobacter genus and another to Acetobacter, being the Gluconobacter strains better prepared for this oxidation. The activities of the membrane-bound dehydrogenases involved in the complete oxidation of D-glucose were measured. Furthermore, the genes encoding for these enzymes were sequenced and used to construct phylogenetic trees, obtaining as a result that Acetobacter and Gluconobacter genera grouped into different clusters. The nutritional requirements, mainly focused on nitrogen, for AAB were also studied. The growth of these bacteria was better in media with a complete combination of amino acids and ammonium. The selected strains were sequenced to improve the monitoring protocols for these bacteria in the process.