Buffered Listeria Enrichment Broth is used for the selective enrichment ofListeriaspp. A modification ofListeriaEnrichment Broth developed by Lovett, this medium was designed to improve the enrichment ofListeriaspp. with the addition of Disodium Phosphate to increase the buffering capacity.Listeriaspp., found in soil, sewage, and river water in addition to unprocessed foods, are Gram- positive, short and motile rods. Cycloheximide in this formulation inhibits saprophytic fungi, while Nalidixic Acid is used to suppress the growth of Gram-negative organisms. Casein Digest of Peptone, Soy Peptone and Yeast Extract supply necessary growth nutrients such as amino acids, peptides, and other nitrogenous sources. Dextrose is an energy source for bacterial growth. Monopotassium, Dipotassium and Disodium Phosphates act as pH buffers, thereby allowing the growth of pH-sensitive bacteria.