FIG. 4.

Effects of adventitious expression of ftsZ carried by the pMT177Z plasmid on the bacterial growth rate in liquid culture and on the CFA of rne deletion mutant strains. (A) Effects of ftsZ complementation on colony formation. KSL2000(pBAD-RNE) or MT2000 (recA⁺ strain; pBAD-RNE) containing the pMT177Z plasmid were grown to mid-log phase at 37°C in LB medium supplemented with 0.1% arabinose and antibiotics. After being washed with LB, the cells were diluted (approximately 10⁻⁵) and the same volume of culture was spread on LB plates containing or lacking 0.1% arabinose. The plates were incubated at 37°C for 72 h. Colonies were seen on the plate containing 0.1% arabinose after 12 h. (B) Effects of pMT177Z on cell growth in strains also complemented by expression of full-length RNase E, N-RNase E, or RNase G. N3433(pKAN7), KSL2000(pBAD-RNE), KSL2009(pBAD-NRNE), and KSL2010(pBAD-RNG) containing either the pACYC177 (pACYC177Δkan for N3433) plasmid or the pMT177Z plasmid were grown at 37°C in LB medium supplemented with arabinose and antibiotics as indicated in Materials and Methods. Increases in cell density were monitored by measuring the OD₆₀₀. At time zero, the OD₆₀₀ values of all cultures were adjusted to 0.1.