Climate change is a pressing global issue that is caused by the consumption of fossil fuels. Cell factories are biological systems that are engineered to produce a wide range of products which can play a crucial part in reducing the dependency on fossil fuels. Within this thesis the genetic toolbox of Pseudomonas taiwanensis VLB120 was expanded and implemented to generate a chassis strain to enlarge the product portfolio of this emerging industrial-relevant cell factory.

While S. cerevisiae is one of the most used hosts in biotechnology, many aspects of its volatile metabolites are sparsely researched. This works aims to demonstrate different topics, for example how CO2 production can be avoided by combining bio- and chemocatalysis, how targeting the production of volatile compounds can lower downstream processing costs, and how SESI-Orbitrap MS opens new possibilities to measure the volatilome online in real-time.

Reduced, valuable compounds can be produced using metabolically engineered microbes. The production of such molecules often relies on redox-cofactor-dependent biocatalysis in microbial production hosts. The prerequisite for outstanding performance requires a basic understanding of the redox metabolism of the production host, a simple redox chassis, and a target molecule. In this thesis, these prerequisites are addressed using the obligate aerobe Pseudomonas taiwanensis VLB120.

Given the persistent growth in demand for food, energy, and chemicals in the coming decades, a shift from fossil-based raw materials to sustainable alternatives is required. Using renewable carbon sources will allow a future that is independent of fossil carbon. Itaconate functions as a bio-based building block with many applications. This work focused on metabolic engineering and bioprocess optimization strategies to establish a sustainable Ustilaginaceae itaconate production using CO2-derived co-substrates.

The life expectancy of liver cirrhosis patients drastically worsens with decompensation. In this work, a clinical score was developed to identify patients at high risk for decompensation enabling targeted treatment. Furthermore, to facilitate treatment and drug development for liver cirrhosis patients, a PBPK framework for liver cirrhosis was developed. The presented work provides two tools for treatment optimization of liver cirrhosis patients potentially improving patient health in the future.