Table 1.
Plackett–Burman experimental design with four independent variables along with the model response BC yield (mgDW/gCPW). The averaged values ± standard deviations from triplicate cultivations after 14 days of static incubation at 30 °C are presented. Factors A, B, C and D correspond to CPW sugars (g/L), initial pH, inoculum concentration (OD600nm) and YE (g/L).
| CPW Sugar Concentration (A) | Initial pH (B) | Inoculum Concentration (C) | YE Concentration (D) | BC Yield (mgDW/gCPW) a | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Runs | g/L | Level | pH | Level | OD600nm | Level | g/L | Level | Final pH | |
| 1 | 40 | +1 | 7 | +1 | 0.05 | −1 | 5 | +1 | 12.0 ± 4.5 | 2.8 |
| 2 | 20 | −1 | 7 | +1 | 0.2 | +1 | 5 | +1 | 34.0 ± 4.6 | 3 |
| 3 | 20 | −1 | 7 | +1 | 0.2 | +1 | 0 | −1 | 13.0 ± 0.9 | 2.8 |
| 4 | 20 | −1 | 5 | −1 | 0.05 | −1 | 5 | +1 | 26.5 ± 2.8 | 3 |
| 5 | 40 | +1 | 5 | −1 | 0.2 | +1 | 5 | +1 | 31.0 ± 10.9 | 2.5 |
| 6 | 20 | −1 | 5 | −1 | 0.05 | −1 | 0 | −1 | 18.0 ± 4.6 | 2.5 |
| 7 | 20 | −1 | 5 | −1 | 0.2 | +1 | 5 | +1 | 31.0 ± 1.5 | 3 |
| 8 | 40 | +1 | 7 | +1 | 0.05 | −1 | 5 | +1 | 23.5 ± 3.2 | 2.5 |
| 9 | 40 | +1 | 7 | +1 | 0.2 | +1 | 0 | −1 | 8.0 ± 2.2 | 3 |
| 10 | 20 | −1 | 7 | +1 | 0.05 | −1 | 0 | −1 | 12.5 ± 2.3 | 3 |
| 11 | 40 | +1 | 5 | −1 | 0.2 | +1 | 0 | −1 | 11.0 ± 0.6 | 2.5 |
| 12 | 40 | +1 | 5 | −1 | 0.05 | −1 | 0 | −1 | 7.0 ± 1.1 | 2.8 |
a The BC yield and the standard deviation values were the means obtained from triplicate experiments and have been rounded to the nearest integer.