Bacterial membrane lipids: diversity in structures and pathways

Abstract

For many decades, Escherichia coli was the main model organism for the study of bacterial membrane lipids. The results obtained served as a blueprint for membrane lipid biochemistry, but it is clear now that there is no such thing as a typical bacterial membrane lipid composition. Different bacterial species display different membrane compositions and even the membrane composition of cells belonging to a single species is not constant, but depends on the environmental conditions to which the cells are exposed. Bacterial membranes present a large diversity of amphiphilic lipids, including the common phospholipids phosphatidylglycerol, phosphatidylethanolamine and cardiolipin, the less frequent phospholipids phosphatidylcholine, and phosphatidylinositol and a variety of other membrane lipids, such as for example ornithine lipids, glycolipids, sphingolipids or hopanoids among others. In this review, we give an overview about the membrane lipid structures known in bacteria, the different metabolic pathways involved in their formation, and the distribution of membrane lipids and metabolic pathways across taxonomical groups.

Profiling and tandem mass spectrometry analysis of aminoacylated phospholipids in Bacillus subtilis

“…In most bacteria, phospholipids are the dominant cell membrane component 1 . The phosphate moieties in these lipid molecules dictate the overall negative nature of bacterial membranes.…”

“…This electrostatic feature makes them susceptible to cationic antibiotic peptides such as defensins 2– 4 . In response to environmental challenges, bacteria constantly change their membrane composition 1, 5 . Incorporation of less saturated and shorter fatty acyl chains makes the membrane more fluidic 1 .…”

“…In response to environmental challenges, bacteria constantly change their membrane composition 1, 5 . Incorporation of less saturated and shorter fatty acyl chains makes the membrane more fluidic 1 . Gram-negative bacteria generally have a high concentration of zwitterionic phosphatidylethanolamine (PE) which masks this anionic surface feature 1, 6 .…”

“…Incorporation of less saturated and shorter fatty acyl chains makes the membrane more fluidic 1 . Gram-negative bacteria generally have a high concentration of zwitterionic phosphatidylethanolamine (PE) which masks this anionic surface feature 1, 6 . In comparison, Gram-positive bacteria in general have much less PE 1 .…”

“…Gram-negative bacteria generally have a high concentration of zwitterionic phosphatidylethanolamine (PE) which masks this anionic surface feature 1, 6 . In comparison, Gram-positive bacteria in general have much less PE 1 . However, they are abundant in aminoacylated phosphatidylglycerol (aminoacyl-PG), especially L-lysyl-PG 5, 7 .…”