Characterization Of P(3hb-Co-4hb) Copolymer Synthesis Consisting Of High 4hb Monomer Using Cupriavidus Sp. Usmaa1020 Transformant Strains

Abstract

Polyhydroxyalkanoates (PHAs) are naturally-occurring biodegradable thermopolyesters accumulated by bacteria. Copolyester of Poly(3- hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] were noted for its high biocompatibility. This makes it an excellent candidate for medical as well as biopharmaceutical applications. A Gram-negative bacteria, Cupriavidus sp. USMAA1020 has the ability to synthesized P(3HB-co-4HB) copolymer with various 4HB monomer compositions. Additional copies of PHA synthase gene (PhaC) from Cupriavidus sp. USMAA1020 (PhaC1020) and Cupriavidus sp. USMAA2-4 (PhaC2-4) the key enzyme in PHA synthesis into Cupriavidus sp. USMAA1020 wild-type strain resulted in higher 4HB monomer composition of the copolymer produced. The transformant strains was cultivated with 1,6-hexanediol (0.5175 wt%) and γ-butyrolactone (0.1725 wt%) through one-stage cultivation. 4HB composition up to 93 mol% obtained by Cupriavidus sp. USMAA1020phaC1020 while 91 mol% 4HB molar fraction was obtained by Cupriavidus sp. USMAA1020phaC2-4.