TY - JOUR
T1 - Biosynthesis and characterization of hydroxybutyrate-hydroxycaproate copolymers
AU - Caballero, Kathryn P.
AU - Karel, Steven F.
AU - Register, Richard A.
N1 - Funding Information:
use of the gas chromatograpahn d to D.J. Quiram for help with the DSC. Fellowships upportf or K.P.C. wasg enerousplyr ovidedb yt heS hellF oundationP.a rtial support was also provided by PYI and NYI awards from the National Science Foundation (EET-8657409, Biotechnology, to S.F.K.; DMR-9257565, Polymers Program, to R.A.R.).
PY - 1995
Y1 - 1995
N2 - Most polyhydroxyalkanoates (PHAs) reported to date fall into one of two broad classes: either hydroxybutyrate-hydroxyvalerate copolymers (typified by the PHA produced by Alcaligenes eutrophus), or hydroxyoctanoate-rich heteropolymers (typified by the PHA produced by Pseudomonas oleovorans). Few reports of copolymers rich in hydroxybutyrate (HB), but containing a minor proportion of a co-monomer with a'higher carbon number than valerate, have appeared. Here we report on the biosynthesis and characterization of HB-rich polymers containing 2-4mol% of hydroxycaproate (HC) units, as well as a terpolymer containing HC and hydroxyoctanoate (HO) units. These polymers were produced in good yield by Comomonas testosteroni, Bacillus cereus and an unidentified third organism when grown on caproate or octanoate. The minor co-monomers were found to be rejected from the PHB crystallites by X-ray analysis and by quantitative analysis of the melting point depression. The greatly reduced melting point, coupled with the retention of a high degree of crystallinity, could make these materials attractive as melt-processible thermoplastics.
AB - Most polyhydroxyalkanoates (PHAs) reported to date fall into one of two broad classes: either hydroxybutyrate-hydroxyvalerate copolymers (typified by the PHA produced by Alcaligenes eutrophus), or hydroxyoctanoate-rich heteropolymers (typified by the PHA produced by Pseudomonas oleovorans). Few reports of copolymers rich in hydroxybutyrate (HB), but containing a minor proportion of a co-monomer with a'higher carbon number than valerate, have appeared. Here we report on the biosynthesis and characterization of HB-rich polymers containing 2-4mol% of hydroxycaproate (HC) units, as well as a terpolymer containing HC and hydroxyoctanoate (HO) units. These polymers were produced in good yield by Comomonas testosteroni, Bacillus cereus and an unidentified third organism when grown on caproate or octanoate. The minor co-monomers were found to be rejected from the PHB crystallites by X-ray analysis and by quantitative analysis of the melting point depression. The greatly reduced melting point, coupled with the retention of a high degree of crystallinity, could make these materials attractive as melt-processible thermoplastics.
KW - X-ray scattering
KW - copolymer
KW - poly(hydroxybutyrate)
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U2 - 10.1016/0141-8130(95)93522-Y
DO - 10.1016/0141-8130(95)93522-Y
M3 - Article
C2 - 7547720
AN - SCOPUS:0029029485
SN - 0141-8130
VL - 17
SP - 86
EP - 92
JO - International Journal of Biological Macromolecules
JF - International Journal of Biological Macromolecules
IS - 2
ER -