Table 5 pH values, concentrations of undissociated (Und.) acids (g/kgDM) and listeria counts in contaminated silages after 30 days. MIC values for L. monocytogenes are given for comparison.
From: Survival of Listeria monocytogenes in Wilted and Additive-Treated Grass Silage
Silages treated with: | MIC values (g/kgDM) after [21] | ||||
|---|---|---|---|---|---|
No additive | Formic acid | Lactic acid bacteria | Anaerobic conditions | Aerobic conditions | |
Low DM level (200 g/kg) | |||||
pH | 4.9 | 4.3 | 3.9 | 4.5 to 5.1 | 4.8 to 5.1 |
Und. lactic | 5.8 | 20.7 | 61.3 | 0.36 | 1.44 |
Und. acetic | 3.3 | 8.1 | 8.7 | 0.96 | 1.44 |
Und. formic | <0.1 | 0.7 | <0.1 | - | - |
Sum of undissociated acids | 9.1 | 29.5 | 70.1 | - | - |
L. monocytogenes (log cfu/g) | 2.3 | nd | nd | - | - |
Medium DM level (430 g/kg) | |||||
pH | 5.8 | 5.5 | 4.1 | 4.5 to 5.1 | 4.8 to 5.1 |
Und. lactic | 0.3 | 0.2 | 30.9 | 0.12 | 0.48 |
Und. acetic | 0.3 | 0.3 | 4.1 | 0.32 | 0.48 |
Und. formic | 0 | <0.1 | 0 | - | - |
Sum of undissociated acids | 0.7 | 0.5 | 35.0 | - | - |
L. monocytogenes (log cfu/g) | 7.9 | 4.2 | nd | - | - |