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TY - THES AU - Niehoff, Paul-Joachim TI - Development of an itaconic acid production process on alternative feedstocks PB - Rheinisch-Westfälische Technische Hochschule Aachen VL - Dissertation CY - Aachen M1 - RWTH-2024-04243 SP - 1 Online-Ressource : Illustrationen PY - 2024 N1 - Veröffentlicht auf dem Publikationsserver der RWTH Aachen University N1 - Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2024 AB - The establishment of biorefinery concepts is hindered by their economic disadvantages compared to conventional petrochemical production routes. For the production of bulk chemicals via microbial cultivation, substrate costs are a major contributor to the overall costs. Therefore, the use of locally sourced alternative feedstocks is of key importance for the transition towards a decentralized and sustainable bioeconomy. In this thesis, a production process for itaconic acid was developed using alternative feedstocks as sole carbon source. Early-stage process development was conducted in small-scale shaken bioreactors like microtiter plates and shake flasks. In the first part of this work, five different Ustilago strains were screened for their growth and production of itaconic acid on defined media. U. cynodontis ITA Max pH, a highly engineered production strain, was selected to determine the biologically available nitrogen concentration in thick juice and molasses. Based on these findings, thick juice was chosen as feedstock to ensure the necessary nitrogen limitation for itaconic acid production. U. cynodontis ITA Max pH was further characterized regarding osmotolerance and product inhibition. A successful scale-up to a 2-liter stirred tank reactor was accomplished without drawbacks in either titer or yield compared to pure glucose fermentations. The process was then further optimized regarding pH, nitrogen concentration, and pH adjusting agent before being scaled to a 150 L bioreactor. The fermentation shows the proof-of-concept for the scale-up of itaconic acid production with an alternative feedstock as the sole carbon source. Especially early-stage bioprocess development is impossible without shake flasks. To evaluate the suitability of different shake flask sizes, a procedural analysis of the commercially available shake flasks from 50 – 5000 mL was conducted. This analysis showed that no general recommendation for a specific parameter set can be made, which is valid for all cultivations. These rather depend on the chosen production strain and process. This study describes an approach for fast and reliable process development for biorefinery concepts and highlights the importance of engineering parameters for the successful implementation of shake flasks within the process development of these concepts. LB - PUB:(DE-HGF)11 DO - DOI:10.18154/RWTH-2024-04243 UR - https://publications.rwth-aachen.de/record/984806 ER -