Microbial cell wall and envelope

The microbial cell wall and envelope are essential structural layers that protect bacteria and fungi from environmental stress and osmotic pressure. In bacteria, the cell wall is characterized by a peptidoglycan scaffold, which is thick in Gram-positive species and thin in Gram-negative species, the latter of which also features an outer membrane rich in lipopolysaccharides (Silhavy et al., 2010, Cold Spring Harb Perspect Biol). Fungal cell walls differ significantly, being composed of chitin, glucans, and mannoproteins, while their plasma membranes contain ergosterol as the primary sterol (Gow et al., 2017, Microbiology Spectrum). These structures are critical for maintaining cell shape, facilitating division, and mediating interactions with the host immune system. Because many components of the microbial envelope are absent in human cells, they represent highly selective targets for antimicrobial therapy (Kohanski et al., 2010, Nature Reviews Microbiology). Drugs such as beta-lactams and glycopeptides interfere with peptidoglycan synthesis, while echinocandins target fungal glucan synthesis, and polymyxins or polyenes disrupt membrane stability, ultimately leading to microbial lysis and death (Poirel et al., 2017, Clinical Microbiology Reviews).

Other names

Bacterial cell wallFungal cell wallCell envelopePeptidoglycan layerBacterial outer membraneMicrobial envelope

Inhibition of peptidoglycan cross-linking (transpeptidation), inhibition of cell wall polymer synthesis (e.g., beta-glucan), and direct disruption of membrane integrity or permeability.