Material utilisation of renewable resources in the form of a bio-based chemical and polymer production will become hugely important in the future. Whereas various possibilities exist for the substitution of fossil fuels in the energy and transport sectors, the only future alternative available for the polymer sector is biomass.
Fermentative Production of Biopolymers
A key focus of activity at PFI Biotechnology is the fermentative production of biopolymers for substitution of petroleum-based plastics.
We are currently conducting research on the production of polyhydroxybutyric acid (PHB) and other polyhydroxyalkanoates (PHA) by means of specific bacterial strains. PHB, PHB copolymers, and other PHAs are intracellular storage substances accumulated by various microorganisms. They can be used to produce thermoplastic biopolymers with excellent material properties which can easily hold their own in competition with petroleum-based plastics such as polyethylene (PE) or polypropylene (PP). In contrast to the latter, however, they are completely biodegradable and can be composted.
Broad application of biopolymers is offset by their still very high prices. These are due, on the one hand, to the cost of raw materials because they are currently produced mainly from sugars (fructose or maltose); on the other hand, separation and purification of PHB from cellular material incur relatively high processing costs.
PHB from Residual Biomass
PFI Biotechnology is therefore pursuing the goal of producing PHB from low-cost residual biomass such as straw. A combination of thermal and enzymatic digestion processes transforms hemicelluloses and lignocellulose into a form suitable for fermentation. Energy for the process is provided by biogas generation from residual materials. In parallel we are investigating new approaches to solvent-free isolation of the target product.
Other research projects include fermentations on the basis of pentoses from hydrolysed hemicelluloses. Production of the valuable sugar alcohol xylitol from xylose with the aid of special yeasts is a key area of activity.