Table 1 Media composition during bioreactors’ operation
a. Media composition tested till the beginning of Experiment 1 as shown in Fig. 1c | |||||
|---|---|---|---|---|---|
Component | Medium variant | ||||
Variant 1 | Variant 2 | Variant 3 * | Variant 4 | Variant 5 | |
Na2HPO4 (g/L) | 6.78 | 6.78 | 1.7 | 0.68 | 1.36 |
KH2PO4 (g/L) | 3.00 | 3.00 | 0.75 | 0.30 | 0.50 |
NaCl (g/L) | 0.50 | 0.50 | 0.13 | 0.05 | 0.10 |
NH4Cl (g/L) | 1.00 | 1.00 | 0.25 | 0.10 | 0.20 |
Yeast extract (g/L) | – | 2.00 | 0.50 | 0.50 | 0.50 |
Substrates | Mixture of short-chain fatty acids and their sodium salts as described for Experiment 1, see part b of the Table | ||||
pH adjustment | + | − | − | − | − |
Final pH | 7.1–7.3 | 6.0–6.3 | 5.0–5.6 | 4.8–5.5 | 4.9–5.5 |
b. Media composition during Experiments 1 and 2 (pH values shown in Table 2) | ||||||||
|---|---|---|---|---|---|---|---|---|
Bioreactor | M1—lactate | M2—butyrate | M3—propionate | M4—acetate | ||||
Substrates in Medium Variant 3 | ||||||||
Experiment | 1 | 2 | 1 | 2 | 1 | 2 | 1 | 2 |
Sodium lactate (g/L) | 10.71 | 15.30 | 1.30 | – | 1.30 | – | 1.30 | – |
Sodium butyrate (g/L) | 1.30 | – | 9.00 | 12.80 | – | – | – | – |
Sodium propionate (g/L) | – | – | – | – | 9.00 | 12.80 | – | – |
Sodium acetate trihydrate (g/ L) | – | – | – | – | – | – | 9.80 | 17.00 |
Butyric acid (g/L) | – | – | – | – | 0.94 | – | 0.94 | – |
Propionic acid (g/L) | 0.96 | – | 0.96 | – | – | – | 0.96 | – |
Acetic acid (g/L) | 0.96 | – | 0.96 | – | 1.00 | – | – | – |