Biosynthesis and Characterization of Polyhydroxyalkanoate Block Copolymer P3HB- b -P4HB
2011; American Chemical Society; Volume: 12; Issue: 9 Linguagem: Inglês
10.1021/bm200660k
ISSN1526-4602
AutoresDie Hu, Ahleum Chung, Linping Wu, Xin Zhang, Qiong Wu, Jinchun Chen, Guo‐Qiang Chen,
Tópico(s)Carbon dioxide utilization in catalysis
ResumoPolyhydroxyalkanoates (PHA) synthesis genes phbC and orfZ cloned from Ralstonia eutropha H16 were transformed into beta-oxidation weakened Pseudomonas putida KTOY08ΔGC, a mutant of P. putida KT2442. The recombinant P. putida strain termed KTHH06 was able to produce a short-chain-length PHA block copolymer consisting of poly(3-hydroxybutyrate) (P3HB) as one block and poly(4-hydroxybutyrate) (P4HB) as another block. One-dimensional and two-dimensional nuclear magnetic resonance (NMR) clearly indicated the polymer was a diblock copolymer consisting of 20 mol % P3HB as one block and 80 mol % P4HB as another one. Differential scanning calorimetric (DSC) showed that P3HB block melting temperatures (T(m)) in the block copolymer P3HB-b-P4HB was shift to low temperature compared with homopolymer P3HB and a blend of P3HB and P4HB. The block copolymer with a number average molecular weight of 50000 Da and a polydispersity of 3.1 demonstrated a better yield and tensile strength compared with that of its related random copolymer and blend of homopolymers of P3HB and P4HB.
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