| Numbering | Coal quality/g | Wheat straw quality/g | Bacteria source/mL | Biogas production/mL | Methane production/mL | Subtract blank group/mL |
| Control | 0 | 0 | 200 | 66.00 | 22.12 | 0 |
| LIG | 20 | 0 | 200 | 205.60 | 61.84 | 39.72 |
| LIG-WS | 20 | 6.25 | 200 | 536.70 | 245.62 | 223.50 |
| WS | 0 | 6.25 | 200 | 365.00 | 120.75 | 98.63 |