Inhibitory action of a non-metabolizable fatty acid on the growth of Escherichia coli: role of metabolism and outer membrane integrity.
The inhibitory action of decanoic acid on both Escherichia coli K-12/154 (normal lipopolysaccharide) and E. coli RC59 (defective lipopolysaccharide) was studied. A correlation was found between the doubling time of E. coli 154 growing in different media and the lethal effect of 0.4% decanoic acid on this bacterium. Decanoic acid (0.4%) exerted a lytic action on glucose-starved and NaN3-inhibited cells of E. coli 154 and RC59. Exponentially growing cultures of both strains were not affected by the addition of 0.4% methyldecanoate, but cells of E. coli RC59 reaching the stationary phase were attacked by that compound. A bactericidal action of 0.4% methyldecanoate on exponential E. coli 154 and RC59 was observed when sodium azide was also present in the media. Concentrations lower than 0.01% methyldecanoate had a lytic effect on spheroplasts from E. coli 154 and RC59. These results indicate that the inhibitory action of a non-metabolizable fatty acid on E. coli depends on the cellular metabolic activity and the outer membrane integrity.
D001386:Azides / Q000494:pharmacology; D001433:Bacteriolysis; D002462:Cell Membrane / Q000502:physiology; D003652:Decanoic Acids / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D013104:Spheroplasts / Q000187:drug effects*
D001386:Azides; D003652:Decanoic Acids