pepton

Pepton is an historical term used to refer to preparations containing peptones, the mixtures of short peptides and amino acids produced by the partial hydrolysis of proteins. In modern terminology, the word peptone is preferred, but older microbiology and physiology texts sometimes use pepton to denote both the hydrolyzed protein digest and solutions that contain it.

Pepton is produced by hydrolyzing proteins such as casein, meat, or gelatin, using acid, alkali, or enzymatic methods. The resulting product is a heterogeneous mixture rich in peptides and amino acids, and it may be sold as a dry powder or as a sterile liquid. In microbiology, pepton-containing preparations serve as nutrient sources in culture media and as diluents for bacterial suspensions, providing a readily utilizable nitrogen source and carbon skeletons for many organisms.

Historically, peptonized preparations and related formulæ were used in digestion studies and as nutritional aids, and the term pepton appears in pharmacology and pathology literature from earlier periods. In contemporary practice, the terminology has largely shifted to peptone, and most current references use that term exclusively, though some laboratory traditions retain the older usage.

See also: peptone, peptone water, culture medium.