Table 2. Experiment design of steepest ascent and corresponding responsea.
| Lactose (g/L) | Peptone (g/L) | Temperature (°C) | EPS production (g/L) | Broth viscosity (mPa•s) | |
| Base pointb | 25.00 | 12.50 | 20.00 | ||
| Origin step unitc | 5.00 | 2.50 | 5.00 | ||
| Sloped | 0.897 | −0.579 | −0.748 | ||
| Proportione | 4.49 | −1.45 | −3.74 | ||
| New unitf | 6.00 | −1.94 | −5.00 | ||
| Experiment 1 | 25.00 | 12.50 | 20.00 | 4.84 | 2203.67 |
| Experiment 2 | 31.00 | 10.56 | 15.00 | 3.17 | 144 |
| Experiment 3 | 37.00 | 8.62 | 10.00 | 7.35 | 4771 |
| Experiment 4 | 42.00 | 6.68 | 5.00 | 1.29 | 24 |
a
X 1, lactose; X 2, Peptone; X 6 , temperature.
b
zero level in the PB design in Table 1.
c
range of the unity level.
d
estimated coefficient ratio from Eq. (1).
e
origin step unit × slope.
f
Proportion ×1.337, where 1.337 is a factor determined by experimenter based on process knowledge or other practical consideration, and 1.337 is appropriate in this example.