Biosynthesis and modification of PHAs
Polyhydroxyalkanoates (PHAs) are biodegradable polyesters produced by bacteria as intracellular storage materials. We have isolated several microorganisms that have very interesting characteristics regarding PHA biosynthesis, and developed novel PHAs containing various functional groups, including cyclohexyl, alkoxy, and unsaturated groups in the side chains. Chemical modifications of these PHAs to produce materials with improved properties which are suitable for biomedical applications have been also developed. We are currently investigating the potential use of waste materials as the cheap carbon substrates for the production of PHAs by mixed cultures enriched under aerobic dynamic feeding.