Uses of Algae

Hello!

Algae that we see in water bodies is actually very useful to human beings and animals. Do you know some of their uses? 

Let's see some of them here:

1. Algae, in form of sea weeds, are used as source of food, e.g., Porphyra, Ulva, Laminaria, etc.

2. Algae are used to produce commercial products like agar agar, a jelly like substance Eg Gelidium, Gracilaria etc. Agar agar is also used as culture media in biotechnology laboratory. 

3. Algae are also useful for producing medicines. Antibiotics are produced from certain algae. 

4. Algae like Nostoc, Anabaena etc. are used as manure or living manure; because they can convert atmospheric nitrogen into nitrogenous compounds. 

5. Algae like Chlorella, Chlamydomonas, etc. are used in purification of sewage or ponds; because they help in bacterial decomposition by providing oxygen. 

6. Algae like Chlorella, Synecoccus, etc are used in space travels; because they provide oxygen and absorb carbon dioxide. 

7. Algae like Laminaria, Fucus, Ascophyllum etc. are used to extract iodine; and Polysiphonia, Rhodymenia are used to extract bromine. 

Can you add some more points here?