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Propionic
Acid
Fermentations |
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Propionic
Acid
Fermentations -
In
this
fermentation,
pyruvate
is
first
carboxylated
to
yield
oxalo
acetate
which
is
then
reduced
to
succinate
and
then
decarboxylated
to
propionate.
The
overall
process
utilizes
four
hydrogens
per
pyruvate
and
for
each
of
two
pyruvates
reduced
to
propionate,
a
third
pyruvate
is
formed
from
a
triose
arid
this
is
then
oxidized
to
acetate
and
CO2
with
the
generation
of
one
mole
of
ATP
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The
propionic
bacteria
can
also
utilize
lactic
acid
which
is
first
oxidized
to
pyruvate,
a
part
of
which
is
then
reduced
to
propionate
and
the
rest
is
oxidized
to
acetate
and
CO2.
In
this
process
one
mole
of
ATP
is
generated
per
nine
carbons
and
because
of
this
propionic
bacteria
generally
grow
very
slowly.
This
fermentation
is
important
in
swiss
cheese
production
in
which
the
propionic
acid
contributes
to
the
characteristic
flavou
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