Table 1 Design of experiment with Taguchi method: selected factors and designated levels
Symbol | Factor | Level | |||
|---|---|---|---|---|---|
L1 | L2 | L3 | L4 | ||
A | Carbon source | Brewer’s spent grain | Waste cooking oil | Molasses | Beet pulp |
B | Nitrogen source | Monosodium glutamate | Ammonium nitrate | Ammonium sulfate | Corn soak |
C | pH | 5 | 6 | 7 | 8 |
D | Inoculum (%) | 3 | 5 | 7 | 9 |
E | Temperature (°C) | 20 | 30 | 37 | 45 |