Gram positive bacteria
|
Gram negative bacteria
|
1.
The bacteria remain coloured with
Gram staining even after washing with alcohol or acetone
|
The bacteria do not
retain the stain when washed with alcohol or acetone. So these type of bacteria
are observed with another stain such as safranin.
|
2.
Outer membrane is absent
|
Present
|
3.
Thicker cell wall. Thickness
varies from 20-80 nm
|
Thin cell wall.
Thickness varies from 8-12 nm
|
4.
Smooth wall
|
Wavy wall and comes
in contact with plasma membrane only at a few loci.
|
5.
The wall contains 70-80% peptidoglycan
(murein or mucopeptide)
|
The wall contains 10-20%
peptidoglycan
|
6.
Teichoic acids may be present
|
Teichoic acids
absent
|
7.
Very little lipid content (0-2%)
|
High lipid content
(20-30%)
|
8.
Lipopolysaccharide layer (LPS)
absent.
|
Present
|
9.
Basal body of the flagellum
contains 2 rings
|
Basal body of the
flagellum contains 4 rings
|
10.
Mesosomes are quite prominent
|
Mesosomes are less
prominent
|
11.
A few pathogenic bacteria belong
to Gram positive group
|
Most of the
pathogenic bacteria belong to Gram negative group
|
12.
E.g. Bacillus subtilis, Mycobacterium,
Noccardia
|
E.g. Escherichia
coli
|
9:44:00 AM
Dr. Kazi Abdus Sobur
Microbiology
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