Morphological bacterial changes caused by compound 16 in B. subtilis. Morphological changes of B. subtilis caused by compound 16 were studied as explained in the Materials and Methods section. B. subtilis was incubated for 2 h at 37 °C in aerobic conditions with 4 × MIC of 16 (D–F). Control (A–C) was bacteria with no antibiotics added. At the end of the incubation, bacteria were fixed and membrane (A,D,G) and DNA (B,E,H) were stained using FM4-64FX (red signal) and DAPI (blue signal), respectively. Membrane and DNA signals were merged in the figure in (C,F,I). The effect of amoxicillin, an inhibitor cell wall synthesis, is shown for comparison in (G–I). Bacteria were observed using confocal microscope and images representative of observed effect were taken. The white scale bar on the bottom right corner corresponds to 4 µm.