Table 1.
Summary of key parameters for the expression and purification of NT*Bri2 BRICHOS expressed in bioreactor cultivations in this study
| Culture | #1 | #2 | #3 | #4 | #5 | #6 | #7 | #8 | #9d |
|---|---|---|---|---|---|---|---|---|---|
| Temperature (°C) | 30 | 30 | 25 | 25 | 25 | 25 | 25 | 25 | 25 |
| Medium | LB | TB | da Silva | Korz | Wyre | da Silva | da Silva | da Silva | da Silva |
| Substrate in feed | Glycerol | Glycerol | Glycerol | Glycerol | Glycerol | Glycerol | Glycerol | ||
| IPTG (µM) | 500 | 500 | 33 | 33 | 33 | 50 | 150 | 500 | 150 |
| OD600 induced | 1 | 0.6 | 30 | 13 | 35 | 32 | 25 | 29 | 60 |
| OD600 harvest | 8.4 | 31 | 121 | 50 | 61 | 190 | 106 | 76 | 176 |
| Induction time (h) | 21 | 21 | 15 | 10 | 10 | 20 | 20 | 20 | 22 |
| Total culture time (h) | 26 | 26 | 39 | 39 | 39 | 47 | 47 | 47 | 49 |
| Culture Size (mL) | 400 | 400 | 325 | 274 | 307 | 910 | 900 | 907 | 1180 |
| Wet Cell Weight (g/L) | 13 | 32 | 197 | 58 | 81 | 200 | 120 | 82 | 214e |
| Expression level (g/L)a | 0.53 | 0.82 | 2.1 | 2.1 | 2.7 | 7.9 | 7.9 | 6.2 | 18.8f |
| % of culture purified | 100% | 100% | 25% | 100% | 50% | 9.1% | 11.6% | 25% | 7.1% |
| Purified (mg)b | 37 | 73 | 40 | 70 | 92 | 133 | 428 | 510 | 540 |
| Yield after purification (g/L)c | 0.09 | 0.18 | 0.49 | 0.26 | 0.60 | 1.61 | 4.12 | 2.25 | 6.41 |
| % of expression level | 17.6% | 22.3% | 23.8% | 11.9% | 22.1% | 20.4% | 51.8% | 36.4% | 34.1% |
aExpression level of NT*-Bri2 BRICHOS was estimated with SDS-PAGE. See also Additional file 1: Figures S2, S3
bProtein yield was calculated using Abs280 and the protein specific extinction coefficient after NT*-Bri2 BRICHOS was eluted and dialyzed to remove imidazole
cYield of NT*-Bri2 BRICHOS after purification
dCulture #9 was repeated 2 more times to estimate the batch-to-batch variation see Additional file 1: Table S1
eDry cell weight for culture #9 was 82 g/L
fThe expression level calculated by considering the % of NT*-Bri2 BRICHOS relative to the total protein content and the dry cell mass is 15.2 g/L