While polymers have become an indispensable part of our daily lives, the vast majority of current commercial polymers are still derived from fossil-based resources and thus contribute to climate change and global warming. Biopolymers, which are biodegradable and derived from renewable and sustainable resources, could offer a solution. However, to be able to cover the broad range of applications of fossil-derived plastics, new types of biopolymers have to be investigated. Even more, the associated production cost should be kept at a minimum to be able to compete with traditional products. With respect to this, the use of industrial gas streams rich in CO2 offers a promising route forward. Yet, in order to capture this CO2 through microbial processes, a significant amount of hydrogen gas is needed, increasing the costs of the process. This project aims to solve this issue by engineering a microbial strain to improve its hydrogen efficiency, thereby significantly lowering production costs. This engineered strain will then be tweaked to produce 2-pyrone-4,6-dicarboxylic acid (PDC) from CO2 as a new and vastly promising building block for the production of biodegradable biopolymers, paving the way towards the sustainable and cost-efficient production of bio-based building blocks for novel polymers with a wide variety of applications.