Date of Award


Document Type




Thesis Advisor

Christopher T. Nomura


Polymers, E. coli


In the medical field, specialty polymers have great potential to meet the demands for bioabsorbable materials as base materials for new technologies. Targeted drug delivery, scaffolds for stem cell growth and intraoperative hemostasis are just a few of the many potential applications for these polymers. Bacterially derived polymers, which are known to be biocompatible, often contain harmful endotoxins. Removal of these endotoxins is necessary to create a safe biocompatible product that meets the FDA requirements on endotoxin limits for implants. This study examines the effectiveness of methanol and sodium hydroxide purification of Clear Coli™ developed by Lucigen and on LSBJ and RSCO2 strains of£. coli. The two purification methods, a non-solvent precipitation and a 0.2 M sodium hydroxide treatment method, were evaluated for their efficacy in removing endotoxin. Poly(3- hydroxybutyrate) was produced in all three strains harboring the recombinant enzymes PhaCl(STQK), PhaA, and PhbB. Sodium hydroxide proved to be the most effective for method of removing endotoxins. After a single round of Na OH purification, 87% of endotoxins were removed from LSBJ and all detectable endotoxins were removed from RSCO2. It required three rounds of methanol purification to achieve a 77% reduction of en do toxin in LSBJ and removal of all detectable levels of endotoxin for RSCO2. Clear Coli was easiest to purify as one round of methanol purification removed 70% of LAL detected endotoxins from the polymer.