Figure 9: Growth of different organisms patterned on a surface
Agarose stamps containing culture media with a square (5 x 5) array of circular posts (1 mm diameter) were used to pattern different organisms. (A) A blue strain of E. coli patterned on BS agar; in the absence of ampicillin, the strain rapidly loses its plasmid, and only some cells produce indigo. (B) B. cereus patterned on BS agar. (C) A schematic showing the location of different bacteria on the agar plate: (1) E. coli clone that produces antibiotics against B. subtilis, (2) E. coli clone that produces indigo (blue), (3) E. coli clone that produces violacein (purple), (4) E. coli clone that produces melanin (brown), and (5) B. subtilis. (D) An image of the colonies after 16 h at 25 C.