Gracilaria lichenoides
(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.] |