FIG 2.

Cell viability and morphology of C. crescentus RNA helicase mutant strains at low temperature. (A) Serial dilutions of the cultures at an OD of 0.1 (10⁻¹ to 10⁻⁵ in 10 μl) were plated in PYE medium and plates were incubated at the indicated temperatures. All strains were incubated at 15°C for 5 days, except for MM82, which was incubated at 15°C for 8 days. The average generation times (G) for four replicates of each culture with the respective standard deviation (SD) are indicated. (B) Cultures were grown in PYE medium at either 30°C or 15°C up to mid-log phase, and the cell morphology was evaluated by light microscopy. The strains used are as follows: NA1000 (wt), MM50 (rhlB), MM74 (rhlE), and MM82 (rhlE-rhlB). Bars indicate 2 μm.