pep·​tone ˈpep-ˌtōn How to pronounce peptone (audio)
: any of various water-soluble products of partial hydrolysis of proteins

Example Sentences

Recent Examples on the Web Once completed, the 60,000 square foot biotech plant will be used to make animal-free peptone proteins that can be used to grow bacteria and other cultures in a lab. Dee Depass, Star Tribune, 22 June 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'peptone.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


German Pepton, from Greek, neuter of peptos cooked

First Known Use

1855, in the meaning defined above

Time Traveler
The first known use of peptone was in 1855

Dictionary Entries Near peptone

Cite this Entry

“Peptone.” Dictionary, Merriam-Webster, Accessed 6 Dec. 2022.

Kids Definition



pep·​tone ˈpep-ˌtōn How to pronounce peptone (audio)
: any of various products that result from the partial breakdown of proteins and that dissolve in water

Medical Definition



pep·​tone ˈpep-ˌtōn How to pronounce peptone (audio)
: any of various protein derivatives that are formed by the partial hydrolysis of proteins (as by enzymes of the gastric and pancreatic juices or by acids or alkalies), that are not coagulated by heat, and that are soluble in water but unlike proteoses are not precipitated from solution by saturation with ammonium sulfate
: a complex water-soluble product that contains peptones and other protein derivatives, is obtained by digesting protein (as meat) with an enzyme (as pepsin or trypsin), and is used chiefly in nutrient media in bacteriology
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