Table 2 The performance of ABE fermentation with various citrate buffer strengths using glucose
Sodium citrate buffer strengths (mM) | |||||||
|---|---|---|---|---|---|---|---|
10 | 20 | 30 | 40 | 60 | 80 | 100 | |
Initial glucose, g/L | 67.0 | 68.0 | 65.0 | 64.0 | 66.0 | 66.0 | 68.0 |
Residual glucose, g/L | 29.0 | 32.0 | 32.0 | 43.0 | 43.0 | 65.0 | 68.0 |
Maximum OD | 2.0 | 1.9 | 1.6 | 1.3 | 0.9 | 0.1 | 0.1 |
Fermentation time, h | 48 | 48 | 36 | 24 | 24 | 0 | 0 |
Butanol, g/L | 9.0 | 8.3 | 6.8 | 4.3 | 4.5 | 0 | 0 |
Acetone, g/L | 4.9 | 4.0 | 3.1 | 2.4 | 2.6 | 0 | 0 |
Ethanol, g/L | 0.2 | 0.2 | 0.2 | 0.1 | 0.1 | 0 | 0 |
Total ABE, g/L | 14.1 | 12.5 | 10.1 | 6.8 | 7.2 | 0 | 0 |
Butanol yield, g/g | 0.24 | 0.23 | 0.21 | 0.20 | 0.20 | 0 | 0 |
Butanol productivity, g/L/h | 0.19 | 0.17 | 0.14 | 0.13 | 0.12 | 0 | 0 |
Acetic acid, g/L | 1.8 | 2.3 | 3.2 | 3.2 | 3.2 | 0 | 0 |
Butyric acid, g/L | 2.1 | 1.8 | 1.3 | 1.1 | 0.8 | 0 | 0 |