Figure 5. Effect of increased outer membrane permeability on Escherichia coli MC4100 resistance to (+)-limonene.

Survival curves of Escherichia coli MC4100 (•) and its defective mutant ΔlptD4213 (▪) after exposure to 200 µL/L of (+)-limonene in citrate-phosphate buffer of pH 4.0 (A) and pH 7.0 (B). Cells were recovered in TSAYE (•, ▪) and TSAYE-SC (sodium chloride: ○, □). Arrows indicate survival counts under detection limit. Error bars indicate standard error.