Our results demonstrate
increasing MIC-values as the pH-level increases for
both SCFA and MCFA. This is in agreement with the
findings in propionic acid made by Kwon and Ricke
(1998) and in anaerobic digester conditions for several
SCFA (Salsali et al., 2006). Even though the MIC
values were comparable between the different SCFA
and MCFA, respectively, subtle differences can be
noted. The MIC values of formic acid, for example,
are highly dependent on pH, showing a large range
between the MIC values at pH 4 and 6. In contrast, the
MIC values of propionic acid are less influenced by
changes in pH. When using these acids to inhibit
growth of Salmonella in feed or drinking water, the
correct combination of acid concentration and pH
should be chosen