Nutrient agar

Nutrient agar
Nutrient agar

Nutrient agar is a microbiological growth medium commonly used for the routine cultivation of non-fastidious bacteria. It is useful because it remains solid even at relatively high temperatures. Also, bacteria grown in nutrient agar grows on the surface, and is clearly visible as small colonies. In nutrient broth, the bacteria grows in the liquid, and is seen as a soupy substance, not as clearly distinguishable clumps. Nutrient agar typically contains (w/v):[1]

  • 0.5 % Peptone
  • 0.3 % beef extract/yeast extract
  • 1.5 % agar
  • 0.5% NaCl

distilled water

  • pH adjusted to neutral (6.8) at 25 °C.

Nutrient broth is made identically, except omitting the agar.


  1. ^ American Public Health Association, American Chemical Society, Association of Official Agricultural Chemists (1920). Standard Methods for the Examination of Water and Sewage. American public health association. pp. p. 95.,M1. 



Wikimedia Foundation. 2010.

Look at other dictionaries:

  • nutrient agar — noun any culture medium that uses agar as the gelling agent • Syn: ↑agar • Hypernyms: ↑culture medium, ↑medium • Hyponyms: ↑blood agar • Substance Meronyms: ↑ag …   Useful english dictionary

  • Casein nutrient agar — (CN) is a growth medium used to culture isolates of lactic acid bacteria such as Streptococcus thermophilus and Lactobacillus bulgaricus . It is composed of standard nutrient agar with the added ingredient of skim milk powder, which contains… …   Wikipedia

  • Agar — or agar agar is a gelatinous substance derived from seaweed. Historically and in a modern context, it is chiefly used as an ingredient in desserts throughout Japan, but in the past century has found extensive use as a solid substrate to contain… …   Wikipedia

  • agar — a gar, n. [See {agar agar}.] 1. common shortened form of {agar agar[2]}. Syn: gelose, agar agar. [PJC] 2. 1 any culture medium that uses agar as the gelling agent; used especially with a modifying prefix, as, EMB agar. The term is applied both to …   The Collaborative International Dictionary of English

  • Agar plate — Infobox Laboratory equipment name = Agar plate caption = An agar plate streaked with microorganisms isolated from a deep water sponge. Individual colonies may be seen center right. acronym = other names = uses = Culturing inventor = manufacturer …   Wikipedia

  • agar — A complex polysaccharide (a sulfated galactan) derived from seaweed (various red algae); used as a solidifying agent in culture media; it has the valuable property of melting at 100°C, but not solidifying until 49°C. [Bengalese] bile salt a. an a …   Medical dictionary

  • nutrient culture medium — a bacterial culture medium containing beef extract and peptone, used as a liquid medium (nutrient broth) or solidified with agar (nutrient agar, plain agar) for the culture of nonfastidious organisms …   Medical dictionary

  • agar-agar — noun a colloidal extract of algae; used especially in culture media and as a gelling agent in foods • Syn: ↑agar • Hypernyms: ↑gum • Substance Holonyms: ↑agar, ↑nutrient agar …   Useful english dictionary

  • agar — n. an extract of certain seaweeds that forms a gel suitable for the solidification of liquid bacteriological culture media. Blood agar is nutrient agar containing 5–10% horse blood, used for the cultivation of certain bacteria or for detecting… …   The new mediacal dictionary

  • Agar nutritivo — El Agar nutritivo es un medio de cultivo usado normalmente como rutina para todo tipo de bacteria. Es muy util porque permanece solido incluso a relativas altas temperaturas. Además, el crecimiento bacteriano en este agar lo hace en la superficie …   Wikipedia Español

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”