Bacillus cereus, a strong lecithinase positive organism, can be identified using Mannitol-egg yolk-polymyxin (MYP) agar plates. It is an aerobic spore producing organism that is found commonly in soil, in many raw and processed foods,on vegetables, and often a causative agent of food poisoning. MYP Agar contains beef extract and peptone as sources of carbon, nitrogen, vitamins and minerals. D-Mannitol is the carbohydrate source. Phenol red is the pH indicator. Agar is the solidifying agent. Egg Yolk Enrichment 50% provides lecithin. Antimicrobial P is Polymyxin B which inhibits the growth of most other bacteria. Bacteria that ferment mannitol produce acid products and form colonies that are yellow. Bacteria that produce lecithinase hydrolyze the lecithin and a zone of white precipitate forms around the colonies. B. cereus is typically mannitol-negative, produce pink-red colonies in MYP agar with a zone of precipitate around the colonies, indicating lecithinase-positive activity.