The organic solvent tolerance of Escherichia coli was measured under condit
ions in which OmpF levels were controlled by various means as follows: alte
ration of NaCl concentration in the medium, transformation with a stress-re
sponsive gene (marA, robA, or soxS), or disruption of the ompF gene. It was
shown that solvent tolerance of E. coli did not depend upon OmpF levels in
the membrane.