Table 1.
Molecular mass distribution of PHB in transgenic fiber
| Fraction no. | Molecular weight × 103 Da | Fiber
|
A. eutrophus
|
||
|---|---|---|---|---|---|
| μg | % | μg | % | ||
| 1 | >1800 | 0.65 | 2.2 | 0.0 | 0.0 |
| 2 | 1800 | 8.6 | 28.9 | 0.71 | 7.8 |
| 3 | 900 | 6.5 | 21.8 | 1.6 | 17.8 |
| 4 | 600 | 4.6 | 15.4 | 1.4 | 15.6 |
| 5 | 400 | 3.1 | 10.4 | 1.9 | 21.1 |
| 6 | 220 | 2.1 | 7.0 | 1.3 | 14.5 |
| 7 | 165 | 1.7 | 5.7 | 0.84 | 9.2 |
| 8 | 110 | 1.2 | 4.0 | 0.66 | 7.2 |
| 9 | <110 | 1.4 | 4.6 | 0.6 | 6.6 |
| Total | — | 29.85 | 100 | 9.01 | 99.8 |
| Recovery | 29.85/29.7 | 100.5% | 9.01/9.3 | 96.9% | |
PHB isolated from fibers was size-fractionated by gel permeation HPLC using ProGel TSK column (G5000-HXL; Supelco), and 0.5 ml fractions were collected. Each fraction was converted to crotonic acid by acid hydrolysis and quantitated by HPLC. Similarly a duplicate experiment was conducted using PHB granules from A. eutrophus (Sigma). Polystyrene molecular weight standards (nominal mol. wt. range of 0.11 × 106 to 1.8 × 106; Supelco) were used to calibrate the column.