Biopolymers

The global potential of bioplastics in numerous markets is surprisingly at odds with low development at industrial scale. High costs from processed feedstock and those associated with product recovery from inefficiently fermented broth delays its implementation. Polyhydroxybutyrate (PHB) is the best studied biodegradable bioplastic and Cupriavidus necator one the most common wild bacterial strain that synthesizes it from substrates different from sugars. In this work, glycerol has been exploited as inexpensive biological feedstock and the understanding gained of PHB synthesis translated to a mathematical model that can be used for process evaluation. This low-structured model is a robust tool for forecasting the fermentation profiles and identifying the best operational conditions, which greatly reduces the number of experiments needed to optimize the process. Due to the nature of the PHB synthesis, accumulated intracellular whenever environmental conditions deprive cells of growing, fed-batch configuration is the most widespread practise. In silico studies of continuous and semi-continuous fermentations are being developed in order to maximize the fermentation outcomes through better designs. The integration of PHB production within the biodiesel plants where the glycerol comes from, together with an improved knowledge of the biological process, subject to design, control and optimization, will contribute in reducing the gap between petroleum-based plastics and the bio-base counterparts.