32 Mutz, Mario Marienhagen, Jan Elling, Lothar 162610 160000 RWTH Aachen University Aachen English 1 Online-Ressource : Illustrationen Aromatic compounds have numerous applications in the chemical, pharmaceutical, and food industries. Currently, aromatics are produced chemically, utilizing crude oil or natural gas-based substrates such as benzene, toluene and xylene. These processes have the disadvantage that they use fossil feedstocks and thus contribute to both, environmental pollution and climate change. Here, microbial production of aromatics might represent an alternative for a more environmentally friendly production of these indispensable compounds using renewable substrates. The aim of this study was the construction of Corynebacterium glutamicum strains for the production of anthranilic acid and para-coumaric acid based on renewable feedstocks. For this purpose, rational metabolic engineering strategies were applied including episomal overexpression of heterologous and endogenous genes, gene deletions, and further chromosomal modifications to achieve the accumulation of these aromatic compounds. Anthranilic acid can be decarboxylated to the platform chemical aniline, which is a precursor for the synthesis of polyurethane plastics and likewise by decarboxylation, para-coumaric acid can be converted to para-hydroxystyrene, which is a monomer building block for the manufacturing of plastics and resins. Accumulation of anthranilic acid was achieved by the introduction of feedback-resistant enzyme variants of 3-deoxy-arabinoheptulosonate-7-phosphate synthase and anthranilate synthase to enhance the carbon flux into the shikimate pathway. Subsequently, the introduction of the Isomerase pathway resulted in the production of anthranilic acid from a carbon source mixture of glucose and xylose, which can potentially be obtained from agricultural waste streams. In addition, biosensors were used to identify variants of anthranilate synthase with an increased degree of resistance towards tryptophan-mediated feedback inhibition. The microbial synthesis of para-coumaric acid was achieved by functional implementation of a tyrosine ammonia-lyase, catalyzing the non-oxidative deamination of tyrosine and the product titer was increased by modification of the shikimate pathway for increased tyrosine supply. Finally, the engineered strain was used in a co-cultivation to enable the production of the para-coumaric acid-derived valuable plant polyphenol resveratrol from glucose. This study demonstrates the successful construction of microbial cell factories for the production of aromatic compounds derived from the shikimate pathway. The established processes are based on renewable feedstocks, which could contribute to a sustainable supply of aromatic platform chemicals in the future. Veröffentlicht auf dem Publikationsserver der RWTH Aachen University ; Dissertation, RWTH Aachen University, 2024 ; 2, ; PUB:(DE-HGF)11, ; Dissertation / PhD Thesis Dissertation RWTH Aachen University 2024 2024 RWTH-2024-08997 2024 https://publications.rwth-aachen.de/record/993818