Table 1.
Comparative cell growth and volumetric productivity (protein titre) during recombinant disulphide-bond protein production in oxygen-depleted conditions
| Proteins | Cell growtha and protein titreb | ||||
|---|---|---|---|---|---|
| Culture to flask volume ratio (Oxygen transfer) | Oxygen level | ||||
| 5:50c | 10:50 | 25:50 | 15%d | 3% | |
| scFv13R4 | 5.49 ± 0.05 | 4.35 ± 0.17 | 2.85 ± 0.05 | 5.57 ± 0.09 | 2.43 ± 0.05 |
| 10.78 ± 2.37 mg/L | 6.30 ± 0.63 mg/L | 4.25 ± 0.49 mg/L | 10.40 ± 1.39 mg/L | 3.59. ± 0.45 mg/L | |
| scFv13R4CM | 5.01 ± 0.12 | 4.13 ± 0.09 | 2.83 ± 0.13 | 4.43 ± 0.05 | 2.34 ± 0.05 |
| 8.29 ± 0.76 mg/L | 7.13 ± 1.01 mg/L | 4.72 ± 0.88 mg/L | 9.15 ± 1.39 mg/L | 2.35 ± 0.40 mg/L | |
| RNase A | 3.65 ± 0.09 | 2.56 ± 0.00 | 1.84 ± 0.08 | 2.93 ± 0.05 | 1.92 ± 0.00 |
| 3.24 ± 0.49 mg/L | 3.14 ± 0.50 mg/L | 2.27 ± 0.29 mg/L | 4.55 ± 0.60 mg/L | 2.63 ± 0.41 mg/L | |
| NGRP | 8.87 ± 0.46 | 5.33 ± 0.17 | 3.31 ± 0.09 | 4.83 ± 0.17 | 2.51 ± 0.05 |
| 12.65 ± 2.11 mg/L | 8.83 ± 0.40 mg/L | 3.66 ± 0.78 mg/L | 5.88 ± 1.40 mg/L | 2.99 ± 0.52 mg/L | |
aFinal cell density was measured as Abs600 (Final OD600) recorded 4 h after induction
bTotal protein titre was determined from the Western blot quantification data (glycosylated and non-glycosylated), normalised and converted from sample OD600 of periplasmic fraction and sample volume for Western blot. For the final cell density and protein titre, the average of three biological replicates is shown and the errors indicate standard deviation
c5, 10, and 25 ml of cell culture were grown in 50 ml shake flask to have culture with different culture to flask volume ratio
dVariation in oxygen level was performed by growing the cells in 24-well plate incubated in hypoxic chamber exposed to 3% O2 (hypoxic) or 15% O2 (normoxic). The change (increasing or decreasing) of cell growth and protein titre relative to control (cell cultivation under more oxygenated conditions, 5/50 culture to flask volume ratio or 15% O2) was analysed by t-test with Welch’s correction (Additional file 2: Table S2 and S3)