Pretreatment conditions | Enzyme loadingb | Stage 1 | Stage 1 + stage 2 |
|---|
Soluble fractions | Insoluble fractions | Soluble fractions | Insoluble fractions |
|---|
Glu (g) | GOS(g) | Xyl (g) | XOS (g) | SL (g) | L-GOS (g) | ISL (g) | Glu (g) | Xyl (g) | SL (g) | ISL (g) |
|---|
A | High | 7.5 | 19.7 | 4.0 | 14.7 | 1.2 | 23.8 | 21.8 | 52.7 | 18.6 | 1.2 | 21.8 |
B | Medium | 31.2 | 15.5 | 6.8 | 12.2 | 0.5 | 4.9 | 23.0 | 50.8 | 18.7 | 0.5 | 23.0 |
- aThe calculation is based on 100 g dry weight poplar wood, which contains 54.2 g glucose, 19.1 g xylose and 23.7 g lignin; A: 270°C, water only, 25 mL/minute, 10 minutes; B: 240°C, 0.05% (w/w) H2SO4, 25 mL/minute, 8 minutes; the water consumption for water only (that is, 270°C, 10 minutes, 25 mL/minute) and dilute acid (that is, 240°C, 0.05% (w/w) H2SO4, 8 minutes, 25 mL/minute) operations was approximately 250 mL and 200 mL, respectively, which led to around 0.2 to 0.25% (w/w) overall solid to liquid ratio with a solid loading of 0.5 g. bHigh enzyme loading: 100 mg protein Ctec 2 (93 filter paper units (FPU)) with 20 mg Htec2/g glucan + xylan; medium enzyme loading: 10 mg protein Ctec 2 (9.3 FPU) with 2 mg Htec2/g glucan + xylan. Glu, glucose; Xyl, xylose; XOS, xylooligomers; GOS, soluble glucose oligomers; L-GOS, insoluble glucan derivatives; SL, soluble lignin; ISL, insoluble lignin.
