Abstract: A plating medium for the presumptive identification of Bacillus cereus, Bacillus thuringiensis and/or Bacillus anthrasis that includes a nutrient base to facilitate growth of Bacillus cereus, Bacillus thuringiensis and Bacillus anthrasis, a chromogenic substrate that changes color responsive to the presence of PC-PLC enzymes, and an ingredient that promotes the expression of the PC-PLC enzyme. In a preferred embodiment, the medium includes a second chromogenic substrate that changes color responsive to the presence of PI-PLC enzymes and an ingredient that promotes the expression of the PI-PLC enzyme.