Thermal modulation of fatty acid synthesis in Escherichia coli does not involve de novo enzyme synthesis

An increased ratio of unsaturated to saturated fatty acids was synthesized within 30 s after shift of Escherichia coli K-12 from 42 degrees C to 24 degrees C. This was more than 10-fold faster than the induction of beta-galactosidase. Inhibition of ribonucleic acid or protein synthesis had no effect on the response of fatty acid synthesis to temperature shift.