Abstract
Growth of Escherichia coli K-12 JA300 on agar and in medium in the presence of 10 different organic solvents has been investigated to obtain information on solvent tolerance. Cells grew readily in nutrient medium containing n-octane or isooctane, and some tolerant cells grew in the presence of n-hexane. Cyclohexane and p-xylene were toxic. Bacteriocidal effects of organic solvents agreed with their bacteriostatic effects observed previously. The toxicity correlated with the common logarithm of the partition coefficient of the solvents between n-octanol and water. When 13 cations were assessed for their effects on solvent tolerance, it was found that the organism grown in the presence of Mg2+, Ca2+, Ba2+, or Sr2+ had a higher tolerance level towards n-hexane or cyclohexane. The addition of EDTA to medium decreased the solvent tolerance level of the organism.
