Table 1.
The CCRD matrix used to study the effects of independent variables (initial moisture content of the culture medium, temperature of incubation and supplementation with wheat bran) on the production of protease, lipase, phytase and keratinase by A. niger LBA02 using chicken feather meal as solid substrate
| Runs | Independent variables (coded/real values) | ||
|---|---|---|---|
| x1/Moisture (%) | x2/Temperature (°C) | x3/Wheat bran (%) | |
| 1 | − 1.00 (41) | − 1.00 (24) | − 1.00 (9) |
| 2 | − 1.00 (41) | − 1.00 (24) | + 1.00 (21) |
| 3 | − 1.00 (41) | + 1.00 (36) | − 1.00 (9) |
| 4 | − 1.00 (41) | + 1.00 (36) | + 1.00 (21) |
| 5 | + 1.00 (59) | − 1.00 (24) | − 1.00 (9) |
| 6 | + 1.00 (59) | − 1.00 (24) | + 1.00 (21) |
| 7 | + 1.00 (59) | + 1.00 (36) | − 1.00 (9) |
| 8 | + 1.00 (59) | + 1.00 (36) | + 1.00 (21) |
| 9 | − 1.68 (35) | 0.00 (30) | 0.00 (15) |
| 10 | + 1.68 (65) | 0.00 (30) | 0.00 (15) |
| 11 | 0.00 (50) | − 1.68 (20) | 0.00 (15) |
| 12 | 0.00 (50) | + 1.68 (40) | 0.00 (15) |
| 13 | 0.00 (50) | 0.00 (30) | − 1.68 (5) |
| 14 | 0.00 (50) | 0.00 (30) | + 1.68 (25) |
| 15 | 0.00 (50) | 0.00 (30) | 0.00 (15) |
| 16 | 0.00 (50) | 0.00 (30) | 0.00 (15) |
| 17 | 0.00 (50) | 0.00 (30) | 0.00 (15) |