Table 3.

Antibacterial mechanisms of action proposed for citral.

Microorganism	Mechanism	Ref.
C. sakazakii	Citral affected the cell membrane of C. sakazakii, as demonstrated by the decrease in intracellular ATP concentration, the reduction in pH, and the hyperpolarization of the cell membrane.	[60]
Salmonella enterica serovar Typhimurium	Studies on bacteria showed that citral alters the lipid content of Salmonella enteritidis cell membranes, increasing the proportion of saturated fatty acids.	[53]
E. coli MG1655	Cell death under aerobic conditions was mainly due to oxidative DNA damage and was independent of the tricarboxylic acid cycle, Fenton reaction, and iron availability. Other structures, such as phospholipids, could probably be an important target of citral.	[49]
V. parahaemolyticus	Citral caused damage to the wall and membrane of bacterial cells, based on the observation of morphology by electron microscopy. Treatment with citral at sub-inhibitory concentrations caused a decrease in biofilm formation, motility, extracellular production of polysaccharides, and the levels of transcription of genes.	[47]

ATP: adenosine triphosphate.