Low level of growth occurred with exposure to only peptone or tryptone. It is Malt extract medium modified by the addition of Yeast extract and peptone. It contains yeast extract, peptone, double-distilled water, and glucose or dextrose. The vaccine's polysaccharide sugars are grown separately in soy peptone broths. The enzyme trypsin can hydrolyze a phosphate-containing peptone. YEPD typically contains 1% yeast extract, 2% peptone, and 2% glucose/dextrose in distilled water. They can both oxidise arabinose, but only "S. liquefaciens" can ferment arabinose in peptone water. In the lab, colonies can be cultured in a glucose-salt liquid medium fortified with peptone. Alkaline Peptone Water is used for the cultivation of vibrio. In this test, the organism under consideration is grown in peptone water broth. Peptone iron agar contains the amino acid cysteine and a chemical indicator, ferric citrate. Peptone metabolism by "Shigella" and "Salmonella" alkalises the medium, turning a pH indicator blue. A key component of granada medium is Proteose Peptone N3 (Difco & BD). Development was analyzed with and without supplemented nutrients (glucose, ammonium, phosphate, peptone).