||Gram positive bacteria
||Gram negative bacteria
||They retain the crystal violet stain during gram staining.
||They do not retain the crystal violet stain during gram staining.
|| Cell wall is simple.
||Cell wall is complex.
||They appear blue/purple.
||They appear pink/red.
||The thickness of wall is 20-80 nm.
||Thickness of wall is 10 nm.
||They have thick peptidoglycan cellwall layer (>50%).
||They have thin peptidoglycan layer (10-20%).
||Outer lipopolysaccharide wall layer is absent.
||Outer lipopolysaccharide wall layer is present (13%).
||Cell wall is very rigid and less elastic.
||Cell wall is less rigid and more elastic.
||Teichoic acid is present.
||Teichoic acid is absent.
||There is no protein content.
||There is protein content.
||Periplasmic space is absent.
||Periplasmic space is present.
||Porins are absent.
||Porins are present.
||s- layer is attached to the peptidoglycan layer.
||s- layer is attached to the outer membrane.
||Mesosomes are more prominent.
||Mesosomes are less prominent.
||They produce endospores during unfavourable condition.
||They do not produce endospores usually.
||They produce exotoxins usually.
||They produce endotoxins usually.
||They show high tolerance towards dryness.
||They show less tolerance towards dryness.
||Muramic acid content of cell wall is more in these group (16-20% of dry weight).
||Muramic content of cell wall is less (2-5% of dry weight).
Examples: Bacillus subtilis, Streptococcus, Clostridium
|Examples: E. coli, Rhizobium, Vibrio, Acetobacter
Differences between Gram positive and Gram negative bacteria