What is "agar"

agar \a"gar\, n. [See agar-agar.]

1. common shortened form of agar-agar[2].

   Syn: gelose, agar-agar.

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 dehydrated medium powder containing agar and to the gelatinous medium prepared from it.

   Syn: nutrient agar [WordNet 1.5 +PJC] ||

Agar-agar \A`gar-a"gar\, n. [Ceylonese local name.]

1. A fucus or seaweed much used in the East for soups and jellies; Ceylon moss ( Gracilaria lichenoides).

2. A gelatinlike substance, or a solution of it, prepared from certain seaweeds containing gelose (such as Ceylon moss, Gracilaria lichenoides or other seaweeds of the genera Gelidium, Ceramium, Pterocladia, and Eucheuma), and used for solidifying growth media in the artificial cultivation of bacteria, or as a gelling agent in foods; -- usually called simply agar, by abbreviation.

   Note: In composition it is predominantly a polysaccharide, and is not degraded by most bacteria. It thus almost completely replaced the earlier protein-based gelatins used for fixing bacterial colonies on culture plates, as the gelatins were often dissolved by the proteolytic enzymes common in bacteria.

   Syn: gelose, agar.

n. 1 A gelatinous material obtained from the marine algae, used as a bacterial culture medium, in electrophoresis and as a food additive. 2 (context chemistry English) An agarose, the principle constituent of the commercial gel.

1. n. any culture medium that uses agar as the gelling agent [syn: nutrient agar]

2. a colloidal extract of algae; used especially in culture media and as a gelling agent in foods [syn: agar-agar]

Agar (pronounced , , "") or agar-agar (, , "") is a jelly-like substance, obtained from algae. It was discovered in the late 1650s or early 1660s by Mino Tarōzaemon in Japan, where it is called kanten.

Agar is derived from the polysaccharide agarose, which forms the supporting structure in the cell walls of certain species of algae, and which is released on boiling. These algae are known as agarophytes and belong to the Rhodophyta (red algae) phylum. Agar is actually the resulting mixture of two components: the linear polysaccharide agarose, and a heterogeneous mixture of smaller molecules called agaropectin.

Throughout history into modern times, agar has been chiefly used as an ingredient in desserts throughout Asia and also as a solid substrate to contain culture media for microbiological work. Agar can be used as a laxative, an appetite suppressant, a vegetarian substitute for gelatin, a thickener for soups, in fruit preserves, ice cream, and other desserts, as a clarifying agent in brewing, and for sizing paper and fabrics.

The gelling agent in agar is an unbranched polysaccharide obtained from the cell walls of some species of red algae, primarily from the genera Gelidium and Gracilaria. For commercial purposes, it is derived primarily from Gelidium amansii. In chemical terms, agar is a polymer made up of subunits of the sugar galactose.

Agar is a gelatinous substance with culinary and microbiological uses.

Agar may also refer to:

Agar is both a surname and a given name.