Converting multiple hydrophobic aromatic plastic monomers into a single water-soluble substrate to increase bioavailability for the synthesis of polyhydroxyalkanoates by bacteria using batch, fed batch and continuous cultivation.

We demonstrate the proof of concept of increasing the bioavailability of carbon substrates, derived from plastic waste, for their conversion to the biodegradable polymer polyhydroxyalkanoate [PHA] by bacteria and test various approaches to PHA accumulation through batch, fed batch and continuous culture. Styrene, ethylbenzene, and toluene are produced from the pyrolysis of mixed plastic waste (Kaminsky, 2021; Miandad et al., 2017), but they are volatile and poorly soluble in water making them difficult to work with in aqueous fermentation systems.

Thermodynamic limitations of PHB production from formate and fructose in Cupriavidus necator.

The chemolithotroph Cupriavidus necator H16 is known as a natural producer of the bioplastic-polymer PHB, as well as for its metabolic versatility to utilize different substrates, including formate as the sole carbon and energy source. Depending on the entry point of the substrate, this versatility requires adjustment of the thermodynamic landscape to maintain sufficiently high driving forces for biological processes. Here we employed a model of the core metabolism of C.