ClpP and CsrA are important for growth at low temperature. A) S. Typhimurium C5 and isogenic mutants were grown exponentially in LB at 37°C up to an OD600 of 0.4. The cultures were then serially diluted (10−1-, 10−2-, 10−3-, and 10−4-fold), and 10 μl of each dilution was spotted onto LB plates. The plates were incubated at 10, 15, 21 and 37°C. The result presented is representative at least two experiments. B) The clpP are diluted as in a) and grown first at 10°C for 12 days and then transferred to 37°C for 1 day. A culture grown at 37°C for 1 day is included as control.