Table 1 Batch acidogenesis of sucrose and raffinose mixtures using γ-alumina-supported anaerobic mixed culture
Initial sugar composition | Repeated batch | Final pH | Ethanol (mL/L) | Acetic acid (g/L) | Propionic acid (g/L) | Butyric acid (g/L) | Lactic acid (g/L) | Succinic acid (g/L) | Malic acid (g/L) | Valeric acid (g/L) | Total VFAs (g/L) | Residual sugar (g/L) | Sugar conversion (%) | VFA yield (g/g) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
100% sucrose | 1 | 5.6 | 0.55 | 1.21 | 0.29 | 1.31 | 1.23 | - | - | - | 4.04 | 0 | 100 | 0.20 |
2 | 5.1 | 0.44 | 1.73 | 1.15 | 1.29 | 1.88 | - | - | 2.80 | 8.85 | 0 | 100 | 0.44 | |
3 | 4.7 | 0.34 | 1.50 | 0.79 | 1.05 | 3.43 | - | - | 1.43 | 8.20 | 0 | 100 | 0.41 | |
70% sucrose 30% raffinose | 1 | 5.6 | 0.74 | 1.44 | 0.69 | 2.56 | 0.63 | - | - | - | 5.32 | 0 | 100 | 0.27 |
2 | 5.2 | 0.40 | 1.73 | 1.24 | 1.96 | 0.70 | - | - | - | 5.63 | 0 | 100 | 0.28 | |
3 | 4.9 | 0.20 | 0.99 | 0.64 | 0.94 | 0.81 | - | - | 2.33 | 5.71 | 0 | 100 | 0.29 | |
50% sucrose 50% raffinose | 1 | 5.4 | 1.04 | 1.19 | - | 1.36 | 1.45 | - | - | - | 4.00 | 0 | 100 | 0.20 |
2 | 5.0 | 0.85 | 1.43 | 0.53 | 1.51 | 1.36 | - | - | 2.64 | 7.47 | 0 | 100 | 0.37 | |
3 | 4.7 | 0.30 | 1.04 | 0.47 | 1.01 | 3.77 | 0.86 | 0.94 | - | 8.09 | 0 | 100 | 0.40 | |
30% sucrose 70% raffinose | 1 | 5.5 | 0.98 | 1.53 | 0.35 | 1.77 | 1.09 | 0.86 | - | - | 5.60 | 0 | 100 | 0.28 |
2 | 5.1 | 0.47 | 1.49 | 0.58 | 1.87 | 0.98 | - | - | - | 4.92 | 0 | 100 | 0.25 | |
3 | 4.8 | 0.29 | 1.39 | 0.68 | 1.55 | 2.36 | - | - | 2.32 | 8.30 | 0 | 100 | 0.42 | |
100% raffinose | 1 | 5.2 | 1.4 | 2.63 | 1.55 | 3.20 | 1.11 | - | - | - | 8.49 | 0 | 100 | 0.42 |
2 | 4.9 | 0.6 | 1.11 | 0.51 | 1.34 | 1.36 | - | - | 2.83 | 7.15 | 0 | 100 | 0.36 | |
3 | 4.5 | 0.1 | 0.32 | 0.37 | 0.75 | 4.53 | - | - | - | 5.97 | 0 | 100 | 0.30 |