ace·​to·​gen | \ ə-ˈsē-tə-jən How to pronounce acetogen (audio) , -ˌjen \
plural acetogens

Definition of acetogen

: any of various anaerobic bacteria that produce acetic acid in the form of acetate from the metabolism of certain sugars (such as xylose or glucose) or from carbon dioxide and hydrogen Kangaroos produce barely any methane as their dominant gut flora are acetogens, not methanogens.— Bijal Trivedi, New Scientist, 20 Dec. 2008 Interest in acetic acid synthesis by acetogens has focused on synthesis from biomass-derived sugars …— J. G. Zeikus et al., Science, 8 Mar. 1985

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

First Known Use of acetogen

circa 1895, in the meaning defined above

History and Etymology for acetogen

aceto- + -gen (probably after the earlier adjective acetogenic or the specific epithet of Bacillus acetogenes)

Keep scrolling for more

Learn More about acetogen

Time Traveler for acetogen

Time Traveler

The first known use of acetogen was circa 1895

See more words from the same year

Statistics for acetogen

Cite this Entry

“Acetogen.” Dictionary, Merriam-Webster, Accessed 19 Sep. 2020.

Comments on acetogen

What made you want to look up acetogen? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Homophone Quiz

  • three bears two of them look like theyre whispering to a third bear who looks chuffed to be the center of attention
  • In order to judge how people felt, the senator's office hired a firm to take a ______.
Spell It

Can you spell these 10 commonly misspelled words?

Add Diction

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!