Gram
Negative
Bacterial
Cell
Envelope -
The
walls
of
Gram
negative
bacteria
contain
a
lower
amount
of
peptidoglycan
(5-10%)
and
this
constitutes
the
inner
layer
in
the
cell
envelope.
The
biosynthesis
of
the
peptidoglycan
is
similar
to
that
in
Gram
positive
bacteria
but
the
structure
of
the
peptidoglycan
in
the
Gram
negative
bacteria
is
different.
The
degree
of
cross
linking
between
the
glycan
strands
is
less
and
in
fact,
many
of
the
peptide
chains
are
not
cross
linked
Details
of
biosynthesis
of
the
outer
membrane
components
namely
the
lipopolysaccharide,
the
proteins
and
the
phospholipids
are
now
well
known,
The
biosynthesis
of
lipopolysaccharide
in
Salmonella
involves
the
addition
of
galactose,
glucose
and
n-acetyl
glucosamine
residues
sequentially
from
the
activated
carriers
such
as
UDP-n-galactose,
UDP-glucose
and
UDP-n-acetylglucosamine
to
CMP-KDO
(CMP-2-keto
3-deoxyoctonate).
