Table 1 Optimization of low-cost substrate and culture conditions for lipopeptide production by Bacillus subtilis SNW3
Factors | Ranges |
|---|---|
Temperature (°C) | 15, 30, 37 and 50 |
pH | 2, 4, 6, 8, 10, 12 |
Agitation speed (rpm) | 0, 150, 250 |
Inoculum size (%, w/v) | 0.5, 1, 1.5, 2, 2.5 |
Nitrogen source (0.1%, w/v) | Urea, sodium nitrate, ammonium nitrate |
Carbon source (conc. 2%, w/v) | White beans powder, potato peels powder, molasses, waste frying oil, yeast extract |
Carbon and nitrogen source ratio (W.B.P + W.F.O + U) w/v | 11 + 0.5 + 0.1, 8 + 1 + 0.1, 6 + 1.5 + 0.1, 3 + 2 + 0.1 |