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%0 Thesis %A Sparviero, Sarah %T Online analytics of alginate production with different Azotobacter vinelandii strains %I Rheinisch-Westfälische Technische Hochschule Aachen %V Dissertation %C Aachen %M RWTH-2024-00719 %P 1 Online-Ressource : Illustrationen %D 2023 %Z Veröffentlicht auf dem Publikationsserver der RWTH Aachen University 2024 %Z Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2023 %X In research and industrial production, reproducibility is a key factor, to meet high quality and safety standards and to maintain productivity. Variations of cultivation parameters as well as media components can have an immense impact on the results of biological cultivations. In the first part of this work, the alginate production with Azotobacter vinelandii was characterised. Several strains were compared and the cultivation procedure was optimised. Thus, using the established standard method, the influence of different yeast extracts in varying concentrations on the cultivation of A. vinelandii and its alginate production under microaerobic conditions was investigated. Cultivations with poorly performing yeast extracts were supplemented with grouped amino acids, single amino acids and microelements. Beneficial results were obtained with the supplementation of copper sulphate, cysteine or a combination of both. Inorganic nitrogen sources were investigated regarding their suitability for alginate production. Furthermore, a correlation between the accumulated oxygen transfer and several cultivation parameters was established. The second part of the work deals with a polymer-based feeding technology in microtiter plates. To allow for measurements in a commercial BioLector, positioning of polymer rings at the bottom of the well has been proposed. This strategy disadvantageously requires an adjustment of the software settings of the BioLector, which modifies the measuring position and prevents the blocking of the light path. Within this work, polymer rings were characterised and optimised to overcome that obstacle and allow for measurements in a BioLector without adjustments of the measuring position settings. Different polymer ring heights, colours and positions in the wells were investigated on their influence on maximum oxygen transfer capacity, mixing time and scattered light measurement. Several configurations of black polymer rings were identified that allow unmodified measurements comparable to wells without rings. With these configurations, fed-batch experiments with two model organisms, Escherichia coli and Hansenula polymorpha, were conducted. Oxygen transfer rate, dissolved oxygen tension, pH, scattered light and fluorescence were successfully measured. Using the obtained online data, glucose release rates of 0.36 to 0.44 mg/h were determined. They are comparable to formerly published data of the polymer matrix. This technology enables the generation of a comprehensive process understanding and target-oriented process development for industrial fed-batch processes. %F PUB:(DE-HGF)11 %9 Dissertation / PhD Thesis %R 10.18154/RWTH-2024-00719 %U https://publications.rwth-aachen.de/record/977449