Peptone manufactured under the Difco Bacto Peptone brand is used as an organic nitrogen source in microbiological culture media for cultivation of a variety of bacteria and fungi.

Principles Peptone is an enzymatic digest of animal protein. Bacto Peptone contains nitrogen in a form that is readily available for bacterial growth. Bacto Peptone has a high peptone and amino acid content, with only a negligible quantity of proteoses and more complex nitrogenous constituents.