Topic summary
Monoderm bacteria
Extracted from the Wikipedia article Gram-positive bacteria.
Importance of the outer cell membrane
All gram-positive bacteria are bound by a single-unit lipid membrane, and, in general, they contain a thick layer (20–80 nm) of peptidoglycan responsible for retaining the Gram stain. A number of other bacteria—that are bound by a single membrane, but stain gram-negative due to either lack of the peptidoglycan layer, as in the mycoplasmas, or their inability to retain the Gram stain because of their cell wall composition—also show close relationship to the gram-positive bacteria. For the bacterial cells bound by a single cell membrane, the term monoderm bacteria has been proposed.