Principal Investigator JoAnne Stubbe
The potential for using biological systems as a source of biodegradable thermoplastics is becoming increasingly attractive given the problems associated with oil based polymers. In collaboration with A. J. Sinskey in the Department of Biology studies have been initiated on several recently cloned and expressed genes for polyhydroxybu-tyrate polymerases. The mechanism of initiation, elongation and termination is being elucidated. Structure and DNA shuffling methods will allow identification of polymerases with altered specificity to produce new materials.
Polyhydroxyalkanoates (PHAs), including polyhydroxybutyrates (PHBs) and polyhydroxyvalerates (PHVs), are biodegradable polymers with thermoplastic and/or elastomeric properties. They are synthesized by various bacteria under nutrient-limited conditions as a carbon storage material and are deposited as amorphous granules within the bacteria. Currently, companies such as Metabolix and Proctor and Gamble are pursuing the commercialization of PHAs as competitive plastics. Our research aim is to understand the mechanisms of PHA homeostasis. These mechanisms provide an important paradigm for non-template driven polymerization processes in biology. Ultimately, we would like to apply our knowledge about PHA homeostasis to engineer new biodegradable polymers and produce them in an economically competitive fashion.
Tools we use in the PHB project:(*) Pre-steady state kinetics(*) Biochemical assays(*) Organic synthesis(*) X-ray crystallography(*) Transmission electron microscopy(*) Fluorescence microscopy(*) Molecular biology