Table 2.
Performance of different pretreatment method during cassava-based butanol fermentation
| Organism | Carbon source | Pretreatment | Butanol (g/L) | Ethanol (g/L) | Acetone (g/L) | Butanol yield (g/g) | Butanol productivity (g/L h) | Solvent productivity (g/L h) | Reference |
|---|---|---|---|---|---|---|---|---|---|
| C. saccharoperbutylacetonicum N1-4 | Cassava starch | Enzymatic hydrolysis (commercial enzymes)a | 17.5 | 1.1 | 2.7 | 0.33 | 0.24 | 0.30 | [9] |
| Bacillus subtilis WD 161 and C. butylicum TISTR 1032b | Cassava starch | Coculture | 6.7 | Approx. 0.9 | Approx. 2.1 | 0.21 | 0.09 | 0.14 | [7] |
| C. butyricum TISTR1032 | Cassava pulp and cassava wastewater | Enzymatic hydrolysis (commercial enzymes)c | 2.5 | 1.6 | 0.6 | 0.10 | – | – | [26] |
| C. beijerinckii ATCC 55025 and C. tyrobutyricum 25755d | Cassava starch | Coculture | 6.7 | 1.5 | 4.0 | 0.18 | 0.96 | 1.93 | [24] |
| C. acetobutylicum PW12 | Cassava flour | No pretreatment | 12.1 | 1.9 | 4.9 | 0.27 | 0.13 | 0.21 | [25] |
| Mutant strain ART18 of C. acetobutylicum PW12 | Cassava flour | No pretreatment | 16.3 | 2.4 | 5.8 | 0.31 | 0.19 | 0.28 | [25] |
| Clostridium. sp. strain BOH3 | Cassava flour | No pretreatment | 17.8 | 1.6 | 4.8 | 0.30 | 0.25 | 0.34 | This study |
Approx. approximately
aCommercial enzymes: granular starch hydrolyzing enzymes (α-amylase and glucoamylase)
bABE and acids (acetic acid and butyric acid) concentrations are 9.7 and 7.3 g/L with yeast extract/NH4NO3 ratio of 265/100 (mM/mM) in coculture system, respectively
cCommercial enzymes: Liquozyme® SC DS (α-amylase), Spirizyme® Fuel (glucoamylase), and Novozyme® NS 50012 (multienzyme complex)
dImmobilized coculture in two fibrous-bed bioreactors