Table 5.
Production of lactic acid from pretreated lignocellulosic material using either a separate enzymatic hydrolysis and fermentation process (SHF), or a combined process (SSF)
| Microorganism | Feedstock | Chemical pretreatment | SSF/SHF | Detoxification | Enzymatic hydrolysis | EHa (h) | Inoculum (% v/v) | CLA (g/l) | Y Lc/LA (%) | Y S/LA (%) | Q LA F (g/l/h) | Q LA, O (g/l/h) | Source | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | P. acidilactici DQ2 | Corn stover | 2.5% H2SO4, 3 m, 190C | SSF | Biological 5 days | Acc 1000 15 FPU/g DW | 8 | 20 | 101.6 | 77.2 | ND | 1.06 | 0.45 | Zhao et al. [25] |
| 2 | Bacillus sp. NL01 | Corn stover | 3% H2SO4 2 h RT, 5 m 170C, SE | SHF | Centrifugation after EH | Cell 1.5L 15 FPU/g DW + Novo 188 30 CBU/g DW | 48 | 8 | 61.3 | ND | 70 | 1.46 | 0.67 | Ouyang et al. [21] |
| 3 | B. coagulans DSM2314 | Wheat straw | 10% NaOH, 16 h, 85C | SSF | None | GC220 18 FPU/g DW | 2 | 20 | 40.7 | 43 | 81 | 0.74 | 0.56 | Maas et al. [11] |
| 4 | E. faecalis RKY1 | Oak wood | 0.5%H2SO4 24 h RT, 5 m 215C, SE | SHF | Centrifugation after EH | Cell 1.5L 15 FPU/g DW + Novo 188 30 CBU/g DW | 48 | ? | 93 | ND | 80 | 1.7 | 0.74 | Wee et al. [26] |
| 5 | B. coagulans DSM2314 | Sugarcane bagasse + LF | 0.72% H2SO4, 15 m, 170C, SE | SSF | None | GC220 13.4 FPU/g DW | 5 | 5 | 64.1 | 74 | 80 | 0.78 | 0.72 | This article |
| 6 | B. coagulans DSM2314 | Sugarcane bagasse + LF | 0.72% H2SO4, 15 m, 170C, SE | SSF | None | GC220 13.4 FPU/g DW | 5 | 5 (Fu P) | 74.6 | 87 | 94 | 0.92 | 0.79 | This article |
| 7 | B. coagulans DSM2314 | Sugarcane bagasse | 0.72% H2SO4, 15 m, 170C, SE | SSF | None | GC220 15.2 FPU/g DW | 4 | 5 (Fu P) | 70.4 | 83 | 90 | 1.14 | 0.98 | This article |
| 8 | B. coagulans DSM2314 | Sugarcane bagasse | 0.72% H2SO4, 15 m, 170C, SE | SSF (two-stage) | None | GC220 15.2 FPU/g DW | 6 | 5(Fu P) | 58.7 | 73 | 90 | 1.81 | 1.33 | This article |
LF liquid fraction, RT room temperature, EH enzymatic hydrolysis. Acc accelerase, Cell cellulast, Novo novozymes. nd not determined, Fu P furfural preculture, C LA concentration of lactic acid at the end of the SSF in g/l, Y Lc/LA lactic acid production yield on total lignocellulosic sugars in W/W, Y s/LA estimated conversion efficiency of sugar monomers to lactic acid in W/W, Q LA.F average volumetric lactic acid productivity during fermentation phase in g/l/h, Q LA.O average volumetric lactic acid productivity over the total process in g/l/h, Fu P inoculum precultivated in the presence of 1 g/l furfural
aEnzymatic hydrolysis time required during SHF, or pre-hydrolysis time prior to inoculation during SSF