TABLE 3.
Purification of avicin A
| Purification step | Vol (ml) | Recovery (%) | Protein concn (mg/ml)a | Antimicrobial activity (bacteriocin units/ml) | Sp act (bacteriocin units/mg) | Increase in sp act (fold) |
|---|---|---|---|---|---|---|
| Culture supernatant | 500 | 100 | 19.9 | 1.3 × 103 | 65 | 1.0 |
| Ammonium sulfate precipitate | 50 | 80 | 6.06 | 1.0 × 104 | 1,650 | 26 |
| Ion-exchange chromatography | 10 | 16 | 0.28 | 1.0 × 104 | 35,700 | 570 |
| First reversed-phase chromatography | 2 | 26 | 0.8 | 8.2 × 104 | 1.02 × 105 | 1,600 |
| Second reversed-phase chromatography | 1 | 32 | 0.11 | 2.05 × 105 | 1.86 × 106 | 29,000 |
a
The protein concentration was determined either by determining the optical density at 280 nm or by using the calculated absorbance value for purified avicin A (from the second reversed-phase chromatography fraction) (1 mg/ml = 3.257).