¹Department of Chemistry, State University of New York, College of Environmental Science and Forestry, Syracuse, New York, USA

²Center for Applied Microbiology, State University of New York, College of Environmental Science and Forestry, Syracuse, New York, USA

Correspondence: Christopher T. Nomura, email: ctnomura@esf.edu, phone: 315-470-6854, fax: 315-470-6856

The biocompatibility and transparency of polylactic acid (PLA) based polymers make them valuable materials with uses ranging from commodity plastics to medical applications. However, the low elasticity and heat resistance of PLA homopolymers limit their usefulness. This can be overcome, by producing copolymers of lactic acid such as poly (lactate-co-3-hydroxyalkanoate)s or P(LA-co-3-HA)s. Differences in mole % of lactate or the size of the 3-hydroxyalkanoate unit in P(LA-co-3HA)s lead to variations in the physical properties of the polymer. There are currently no processes for controlled production of P(LA-co-3-HA)s with precise repeating unit composition. Previously, our group engineered a strain of Escherichia coli (E. coli LSBJ) to produce copolymers with specific repeating unit compositions Our research aims to develop a system for biosynthesis of P(LA-co-3-HA) copolymers with desired composition using E. coli LSBJ as a biocatalyst in a high cell density fermentation process. The mole % of lactate and the size of the 3-hydroxyalkanoate unit can be regulated by feeding specific ratios of lactate and different fatty acids to E. coli LSBJ. We can use this method to produce P(LA-co-3-HA) polymers with specific lactate to 3-hydroxyalkanoate ratios yielding polymers with desired physical properties.