Ques.3. Discuss the economic importance of Agar-Agar
Ans. It is jelly-like substance, obtained from some genera of Rhodophyceae. It is universally used as a base for different culture media in laboratories for culturing many fungi, bacteria and some algae. It is often called simply “agar”. Important agar-producing genera in different parts of the world are Gelidium, Gracilaria, Pterocladia, Chondrus and Phyllophora.
The universal use of agar-agar in culture media is mainly because it contains galactose and a sulphate, melts between 90-100°C and becomes solid at low temperatures.
It is also used in packing canned foods, in treatment of constipation and in cosmetic, leather, textile and paper industries. It is also often given as a laxative.
Dried agar-agar is used for proplased stomach by the physicians. Many pills and ointments are also prepared by using agar-agar.