| Components (%) | Basal medium | Test 1 | Test 2 | Test 3 | Test 4 |
|---|---|---|---|---|---|
| Glucose | 2.0 | 2.0 | 1.0 | 1.0 | 2.0 |
| Yeast extract | 1.5 | 1.0 | 1.0 | 0.5 | 0.5 |
| Casein | 1.0 | - | - | - | - |
| (NH4)2SO4 | 0.5 | 0.25 | 0.25 | 0.25 | 0.25 |
| KH2PO4 | 2.0 | 0.1 | 0.1 | 0.1 | 0.1 |
| K2HPO4 | 2.0 | 0.1 | 0.1 | 0.1 | 0.1 |
| MgSO4 | 0.01 | - | - | - | - |
| Na2HPO4 | 1.0 | 0.05 | 0.05 | 0.05 | 0.05 |
| Vitamin C | 0.8 | - | - | - | - |
| Tween 80 | 0.1 | 0.05 | 0.05 | 0.05 | 0.05 |
| CFU/mL (108) | 4.2±0.2 | 3.9±0.6 | 1.9±0.4 | 2.3±0.9 | 5.0±1.5 |