Modeling and Experimental Validation of Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate) Chain Length Distribution

Biodegradable and bio-based polyhydroxyalkanoates (PHAs) are ecological alternatives to conventional crude oil-based polymers. PHAs can be produced by microorganisms using waste streams from the food industry and domestic households, CO2, or other biogenic residues. To increase the current market share of PHAs, producing biopolymers with tailor-made properties by adjusting process parameters is a desirable goal. In the biotechnology community, much is known about different cultivation conditions, e.g., bioreactor concepts or carbon sources, affecting the thermal and mechanical properties of PHAs (McAdam et al., 2020). Those properties depend mainly on chain length distribution and polymer composition. Mathematical modeling can help investigate the effect of different process conditions on chain length distribution quantitatively. This contribution outlines a multiscale model that describes the dynamics of chain length distribution and composition of the copolymer Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate) produced in a fed-batch process with Cupriavidus necator using fructose and propionic acid as carbon sources. Theoretical predictions are compared with experimental findings.