it was observed that the mutated bacteria lost their hemolytic and phospholipase activity. The flagella of B. cereus are encoded by 2 to 5 fla genes, depending on the strain. Identification For the isolation and enumeration of B. cereus, there are two standardized methods by International Organization for Standardization (ISO): ISO 7932 and ISO 21871. Because of B. cereus ability to produce lecithinase and its inability to ferment mannitol, there are some proper selective media for its isolation and identification such as mannitol-egg yolk-polymyxin (MYP) and polymyxin-pyruvate-egg yolk-mannitol-bromothymol blue agar (PEMBA). B. cereus colonies on MYP have a violet-red background and are surrounded by a zone of egg-yolk precipitate. Below is a list of differential techniques and results that can help to identify B. cereus from other bacteria and Bacillus species. Anaerobic growth: Positive Voges Proskauer test: Positive Acid produced from -glucose: Positive -arabinose: Negative -xylose: Negative -mannitol: Negative Starch hydrolysis: Positive Nitrate reduction: Positive Degradation of tyrosine: Positive Growth at above 50 °C: Negative Use of citrate: Positive The Central Public Health Laboratory in the United Kingdom tests for motility, hemolysis, rhizoid growth, susceptibility to γ-phage, and fermentation of ammonium salt-based glucose but no mannitol, arabinose, or xylose. Growth The optimal growth temperature range for B. cereus is 30-40 °C. At , a population of B. cereus can double in as little as 20 minutes or as long as 3 hours, depending on the food product. Ecology Like most Bacilli, the most common ecosystem of Bacillus cereus is the soil. In concert with Arbuscular mycorrhiza (and Rhizobium leguminosarum in clover), they can up-regulate plant growth in heavy metal soils by decreasing heavy metal concentrations via bioaccumulation and biotransformation in addition to increasing phosphorus, nitrogen, and potassium uptake in certain plants. B. cereus was also shown to aid in survival of earthworms in heavy metal soils resulting from the use of metal-based fungicides, showing increases in biomass, reproduction and reproductive viability, and a decrease in metal content of tissues in those inoculated with the bacterium. These results suggest strong possibilities for its application in ecological bioremediation. Evidence of bioremediation potential by Bacillus cereus was also found in the aquatic ecosystem, where organic nitrogen and phosphorus wastes polluting a eutrophic lake were broken down in the presence of B. cereus. In a study measuring the ability of B. cereus to degrade keratin in chicken feathers, bacteria were found to sufficiently biodegrade