Level | A Glucose concentration (g/L) | B Inoculation concentration (%) | C pH | D Temperature (˚C) |
−1 | 0.4 | 3 | 6 | 35 |
0 | 0.6 | 5 | 7 | 37.5 |
1 | 0.8 | 7 | 8 | 40 |