FIG. 4.

Arrangement of ptb-buk operon from C. beijerinckii NCIMB 8052 and Northern blot analysis of RNA isolated from C. beijerinckii NCIMB 8052 following growth in 1 liter of MP2 medium containing 0, 20, or 60 mM sodium acetate and probed with a DNA probe complementary to ptb from C. beijerinckii NCIMB 8052, as indicated by the dotted line. The bars and arrows indicate the sizes of the bands and their corresponding genes in the operon, respectively. Samples were collected following growth for 6, 24, and 48 h, as indicated. Lane M represents biotin-labeled RNA size markers (Ambion), and their corresponding sizes are given on the right. The Northern blot is representative of duplicate experiments. conc., concentration.