March 29, 2014
Plastics produced from unused and non-food plant resources
RIKEN CSRS and Kaneka Corporation have succeeded in producing polyhydroxyalkanoate (PHA) by giving multiple microorganisms aromatic compounds as the sole carbon source. The carbon sources acting as food for the microorganisms in the study are lignin derivatives, which are the major components of plant cell walls. These represent valuable currently unused and non-food plant resources. The experimental results confirmed PHA synthesis by a PHA-producing bacteria, Ralstonia eutropha H16 (Cupriavidus necator), which can utilize a number of aromatic compounds found in lignin derivatives such as 4-hydroxybenzoic acid (4-HBA).
By using 4-HBA, PHA can be stored inside the microbe up to about 63wt% (percent concentration of mass), showing high productivity. The molecular weight of the PHA after refining is slightly lower than PHAs synthesized from sugar or vegetable oils. However, the physical properties of the lignin-derived PHA show potential for the production of plastic products such as films.
This achievement provides insights for building the fundamental technologies to use microbes for producing materials from lignin, a biomass source that has proved difficult to handle. The results can also be applied to reutilization of liquid wastes from paper factories, expanding the horizon for new possibilities in the biomass industry.
ACS Sustainable Chemistry & Engineering doi: 10.1021/sc500066f
S. Tomizawa, J- A. Chuah, K. Matsumoto, Y. Doi, K. Numata,
"Understanding the limitations in the biosynthesis of polyhydroxyalkanoate (PHA) from lignin derivatives".
Enzyme Research Team, Biomass Engineering Program Cooperation Division