Bacterial and fungal cell membranes

Bacterial and fungal cell membranes are essential lipid bilayers that define the boundary of the microbial cell, maintaining homeostasis and facilitating vital processes such as nutrient transport and energy production (NIH, 2023). In bacteria, the membrane is a site for the electron transport chain and cell wall precursor synthesis, while fungal membranes are characterized by the presence of ergosterol, a sterol absent in mammalian cells (StatPearls, 2023). These structures serve as critical therapeutic targets; for instance, polymyxins disrupt the outer membrane of Gram-negative bacteria by binding to lipopolysaccharides, and polyene antifungals like amphotericin B create pores by binding to ergosterol (PubChem, 2024). Because these membranes are fundamental to microbial survival, their disruption often leads to rapid cell death, providing bactericidal or fungicidal activity (PubMed, 2022). However, the structural similarities between microbial and host cell membranes can lead to significant toxicity, such as nephrotoxicity and hemolysis, necessitating careful drug design to achieve selectivity (NCBI, 2021). The bacterial membrane also plays a role in sensing environmental changes and initiating stress responses through various signaling proteins (Wikipedia, 2024). In fungi, the plasma membrane is involved in the secretion of enzymes and the uptake of essential ions like potassium (PubMed, 2023). Resistance mechanisms against membrane-targeting drugs often involve modifications to lipid composition or the charge of the membrane surface (NIH, 2022).

Other names

Microbial membranesCytoplasmic membranesPlasma membranesBacterial outer membraneFungal plasma membrane

Disruption of membrane integrity through pore formation, depolarization of the membrane potential, or competitive binding to essential membrane lipids such as ergosterol or lipopolysaccharides (PubChem, 2024; PubMed, 2022).