TABLE 1.
PHA production in SK2 wild-type and C9 mutant strains grown on different carbon sources
| Strain | Substrate | Mean ± SD
|
|||||||
|---|---|---|---|---|---|---|---|---|---|
| PHA yield (mg/liter)a | Monomer composition of hydroxyalkanoates (mol%)b
|
Molecular mass (kDa)c | |||||||
| C4 | C5 | C6 | C8 | C10 | C12 | ||||
| SK2 wild type | Pyruvate | 6.5 ± 1.2 | 100 | —d | — | — | — | — | 279 ± 23 |
| SK2 wild type | Octadecane | 18.0 ± 3.8 | — | — | 2 ± 0.3 | 20 ± 2.5 | 48 ± 3.7 | 30 ± 2.1 | 277 ± 38 |
| C9 mutant | Pyruvate | 112 ± 16.8 | 98 ± 0.4 | 2 ± 0.1 | — | — | — | — | 352 ± 16 |
| C9 mutant | Octadecane | 2,560 ± 165.1 | — | — | 4 ± 0.2 | 18 ± 2.0 | 37 ± 2.5 | 39 ± 1.8 | 350 ± 42 |
a
To quantify PHA, the polyesters were extracted with chloroform as described in Materials and Method section and accurately weighed after gel permeation and gas chromatography analysis.
b
The molar fraction of polyester was calculated by gas chromatography according to the area of the peak of FAMEs obtained after methanolysis. Pure FAMEs were used for calibration. In all cases, data are means ± standard deviations (two independent cultures subjected to three independent analyses).
c
Molecular mass of polymer; means were determined by a gel permeation chromatograph calibrated with polystyrene.
d
—, not detected.