Table 1.
The kinetic parameters of acarbose fermentation with different fermentation methods.
| Parameter | Cultivation method | ||
|---|---|---|---|
| Control | A | B | |
| Maximum acarbose titer (mg/L) | 3560 | 4950 | 6606 |
| Specific growth rate (1/h) | 0.0086 | 0.0094 | 0.010 |
| Acarbose productivity (mg/L/h) | 21.19 | 29.46 | 39.32 |
| Specific maltose consumption rate (1/h) | 0.0053 | 0.0061 | 0.0103 |
| Specific glucose consumption rate (1/h) | 0.0046 | 0.0048 | 0.0068 |
| Impurity C concentration (mg/L) | 289 | 107 | 212 |
| Impurity C productivity (mg/L/h)a | 1.49 | 0.64 | 1.26 |
| Acarbose/impurity Ca | 12.32 | 46.26 | 31.16 |
aThe value was calculated when acarbose reached its highest titer in the fermentation.
Method A: validamine was added at a final concentration of 20 mg/L in the fermentation medium prior to inoculation in batch culture.
Method B: validamine was added at a final concentration of 20 mg/L in the fermentation medium prior to inoculation in fed-batch culture. Twice feedings of a mixture of 6 g/L glucose, 14 g/L maltose, and 9 g/L soybean flour were performed at 72 h and 96 h.