FIG 4 .

Chloramphenicol induced B. subtilis sliding at subinhibitory concentrations. (A) The chloramphenicol fraction was 2-fold serially diluted, and 10 μl of each dilution was applied onto a filter paper disc 0.6 cm away from B. subtilis. The control was the 40% (vol/vol) methanol solvent. (B) Pure chloramphenicol was serially diluted and added to the agar plate. At 1 µM, the maximal sliding response was induced. The control was the plate without chloramphenicol. Pictures were taken at h 24. Filter disc diameter, 0.6 cm. Bar, 1 cm.