L. buchneri did not metabolize lactic acid in FC with 6% NaCl
when the initial pH was 5.0 (Fig. 1). Oude Elferink et al. (2001) have
shown that the metabolism of lactic acid to acetic acid and 1,2-
propanediol by L. buchneri in laboratory media required acid induction.
They observed that lactic acid was degraded upon incubation
in MRS when cells were grown in chemostat cultures at pH
3.8, 4.0, and 4.3, but not at 5.8. Similar behavior observed in FC
containing 6% sodium chloride suggests that the low pH that is
typical of fermented cucumbers may be favorable for induction of
the lactic acid degrading activity of L. buchneri. It has also been
found that L. buchneri can degrade lactic acid in fermented cucumber
media containing 1.1% calcium chloride at pH 3.2 (Franco
and Pérez-Díaz, 2012b). Further research to determine the lower
pH limit for lactic acid utilization by L. buchneri in cucumber fermentations
is warranted.