Table 4. Material properties of PHB from C. fritschii.
| Sources of PHB | Thermal properties | Mechanical properties2 | Molecular weight | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Tm (°C) | Tg (°C) | Tcc (°C) | ∆Hm (J/g) | Xc (%) | Elongation at break (%) | Tensile strength (MPa) | Young’s modulus (MPa) | Mw (kDa) | Mn (kDa) | Mw/Mn | |
| Commercial PHB1 | 175.4 (159) | 3.5 | 48 | 99 | 68 | 5.8 ± 1.1 | 24 ± 3 | 820 ± 300 | 970 | 330 | 2.9 |
| Chlorogloea fritschii | 171.6 (171) | 3.2 | 54 | 65 | 45 | 5.5 ± 1.8 | 23 ± 6 | 712 ± 256 | 545 | 256 | 2.1 |
Sixteen-d old photoautotrophically-grown cells were transferred to -N-P medium in the dark with 0.1% (w/v) acetate for 6 d. The dried biomass was extracted for PHB. Tm, melting temperature (first melting peak shown in parentheses); Tg, glass-transition temperature; Tcc, cold-crystallization temperature; ∆Hm, enthalpy of fusion; Xc, crystallinity; Mw, weight-average molecular weight; Mn, number-average molecular weight; Mw/Mn, polydispersity.
1Data from Sigma-Aldrich (St. Louis, MO, USA).
2The mechanical properties are shown as the mean ± 1 SD of three independent experiments.