The acidity produced by these bacteriophage-spiked co-cultures was
slightly lower than that observed from the LC-ST co-cultures without
phage during the first 24 h, which might be due to phage invasion
that weakened the acidification ability of the S. thermophilus strain.
Virulent S. thermophilus phageφ101 was previously shown to be
destructive to a corresponding sensitive strain during fermentation