Lactobacilli MRS Broth, also referred to asLactobacillusMRS Broth or LMRS Broth, is an agar medium used for the selective isolation and enumeration ofLactobacillifrom various sources which include feces and dairy. Beef Extract and Yeast Extract provide amino acids, peptides, carbohydrates, vitamins, and minerals. Sodium Acetate and Ammonium Citrate serve as both selective agents and energy sources. Potassium Phosphate acts as pH buffer, while Magnesium and Manganese Sulfates provide divalent cations essential for bacterial metabolism. Tween 80 is a surfactant to facilitate nutrient uptake by theLactobacilli. Dextrose is not included in this version of the formulation to provide the user with the freedom to incorporate a desired carbohydrate for additional selectivity.