Table 1 Microbial chain elongation operation and maximum rate of medium chain fatty acid production
From: Electricity-assisted production of caproic acid from grass
Feed source | Operation | Culture | pH | Maximum rate of production (g L−1 h−1) | Reference |
|---|---|---|---|---|---|
Synthetic medium containing acetate, ethanol, and yeast extract, with CO2 gas flow | Packed bioreactor | Mixed (non-sterilized, mainly Clostridium kluyveri) | 6.5–7.2 | 2.39 (medium chain fatty acids) | [26] |
Grass fermentation effluent containing lactic acid | Semi-continuous | Mixed (non-sterilized, mainly Clostridium cluster IV) | 5.5–6.2 | 0.99 (caproic acid) | This study |
Synthetic medium containing galactitol, yeast extract, with in situ extraction | Batch | Pure (Clostridium sp. BS-1) | 6.5 | 0.34 (caproic acid) | [12] |
Dilute ethanol and acetate, with in-line extraction | Continuous | Mixed (non-sterilized, mainly Clostridium spp.) | 5.2–5.5 | 0.33 (caprylic acid) | [27] |
Synthetic medium containing acetate and ethanol | Semi-continuous | Mixed (non-sterilized, mainly Clostridium kluyveri) | 7 | 0.20 (caproic acid) | [28] |
Castor oil | Continuous | Mixed (non-sterilized, mainly Clostridium kluyveri) | 6.5–7 | 0.19 (caproic acid) | [29] |
Yeast fermentation beer | Continuous | Mixed (non-sterilized, mainly Clostridium kluyveri) | 5.5 | 0.14 (caproic acid) | [30] |
Diluted yellow water | Semi-continuous | Mixed (non-sterilized, mainly Clostridium cluster IV) | 5.5–6.5 | 0.12 (caproic acid) | [3] |