Differences between Gram Positive and Gram Negative Bacteria

Differences between Gram Positive and Gram Negative Bacteria

S.N.	Characteristics	Gram Positive	Gram Negative
1	Gram Reaction	Retain crystal violet dye and stain blue or purple	Can be decolorized to accept counterstain (safranin) and stain pink or red
2	Cell Wall	Cell Wall is 20-30 nm thick.	Cell Wall is 8-12 nm thick.
3	Cell Wall	The wall is Smooth.	The wall is wavy.
4	Peptidoglycan Layer	Thick (multilayered)	Thin (single-layered)
5	Teichoic Acids	Present in many	Absent
6	Periplasmic Space	Absent	Present
7	Outer Membrane	Absent	Present
8	Porins	Absent	Occurs in Outer Membrane
9	Lipopolysaccharide (LPS) Content	Virtually None	High
10	Lipid and Lipoprotein Content	Low (acid-fast bacteria have lipids linked to peptidoglycan)	High (because of presence of outer membrane)
11	Mesosomes	Quite Prominent	Less Prominent
12	Flagellar Structure	2 rings in basal body	4 rings in basal body
13	Toxin Produced	Exotoxins	Endotoxins or Exotoxins
14	Resistance to Physical Disruption	High	Low
15	Cell Wall Disruption by Lysozyme	High	Low (requires pretreatment to destabilize outer membrane)
16	Susceptibility to Penicillin and Sulfonamide	High	Low
17	Susceptibility to Streptomycin, Chloramphenicol and Tetracycline	Low	High
18	Inhibition by Basic Dyes	High	Low
19	Susceptibility to Anionic Detergents	High	Low
20	Resistance to Sodium Azide	High	Low
21	Resistance to Drying	High	Low

Differences between Gram Positive and Gram Negative Bacteria