Agar-agar

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  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}).
        [1913 Webster]
  
     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.
          [Webster 1913 Suppl.]

From WordNet (r) 2.0 [wn]:

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