Economic importance of Algae
Since from olden days Algae species are intimately connected with human beings as a source food, medicine and other uses. Algae are taking an active role in human beings.
1. Primary Producers:
Algae are the main Oxygen producers in aquatic areas. They are also useful in decreasing water pollution by realizing Oxygen. 10% of photosynthesis is occurred by the algae in total photosynthesis quantity. With these activity algae forms 1.6-15.5 x 10 to the power of 11 tones of carbonic material like food.
2. Algae as food:
Algae species are used as food in several countries in several forms. Algae species have proteins, vitamins (A, B, C and E), lipids, and minerals. Laminaria species is the important edible seaweed in Japan and the food item ‘Kombu’ is prepared from it. ‘Aonori’ from Monostroma; ‘Asakusa Nori’ from Porphyra are prepared in different countries. Porphyra has 35% protein, 45% carbohydrates, Vitamins B and C and Niacin. Nostoc is used as food material in South America.
3. Algae as fodder for cattle:
Rhodymenia palmate is used as food for sheeps in Narvey. Laminaria saccharina, Pelvitia, Ascophyllum, etc. species are used as food for cattles.
4. Algae as fertilizers:
Blue-green algae are treated as bio-fertilizers from olden days. Nostoc, Oscillatoria, Scytonema, Spirulina, etc. are used as fertilizers to rice fields. All these algae are fixed the atmosphere Nitrogen in to ground. Cultivation of Spirulina is gaining importance as feed for fish, poultry and cattle.
5. Algae in Pisi culture:
Sea algae are used as food for fishes. So they play an important role in Pisi culture. Some green-algae, Diatoms, some blue-green algae are used as food material to fishes. These are also making the water clean, by realizing Oxygen.
6. Algae in reclamation of alkaline or Usar soils:
Our country has more number of alkaline soils or sterile soils. Blue-green algae like Nostoc, Oscillatoria, Scytonema, Spirulina are modified the soils in to fertile soils. Because they fixed Nitrogen in to soil. Nearly they fixed 400 K.g. of Nitrogen per year. Soil erosion is also reduced by these algae.
7. Algea in industry:
Iodine industry is mainly depended upon algae. Algae belonging to Phaeophyceae, like Laminaria, Ecklonia, Eisenia, etc. are used in the industry to prepare Iodine in industries. Phyllophora is used to prepare Iodine in Russia.
Alginates are the salts of alginic acid found in the cell wall of phaeophyceae. Alginates are extracted from Fucus, Laminaria, Macrocystis and Ecklonia. Alginates are used in the preparation of flame-proof fibrics, plastics, paints, gauze material in surgical dressing, soups, ice creams etc.
Agar-agar is a jelly like substance of great economic value. It is obtained from certain red algae like Gelidium, Graciliaria, and Gigartina. Agar is used as a culture medium for growing callus in tissue culture.
10. Carragheen or Carragheenin:
It is extracted from cell walls of red algae like Chondrus and Gigartina. It is a polysaccharide esterfied with sulphate. It is used as emulsifier in pharmaceutical industry and also in textile, leather, cosmetics and brewing industries.
Diatoms deposits at marine and fresh water areas. They are rich with silica. It is called as diatomite. It is used in the preparation of Dynamite in olden days. But now it is used in different industries like glass, metal polishing, paints, tooth pasts, soups, etc.
It is a type of glue obtained from a red alga Gloipeltis furcata. It is used as an adhesive as well as sizing agent for paper and cloth. Chemically it is similar to agar-agar except that there is no sulphate ester group.
The brown sea weeds popularly called as kelps yield potash, soda, and iodine. Some sea weeds are rich source of iron, zinc, copper, manganese and boron. Bromine is extracted from red algae such as Polysiphonia and Rhodymenia.
14. Antibiotics and Medicines:
Antibiotic Chlorellin, obtained from Chlorella is effective against a number of pathogenic bacteria. Extracts from Cladophora, Lyngbya can kill pathogenic Pseudomonas and Mycobacterium. Laminaria is used as one of the modern tools for abortion. Seaweeds have beneficial effect on gall bladders, pancreas, kidneys, uterus and thyroid glands.
15. Role of Algae in Sewage Disposal:
Some species like Chlamydomonas, Scenedesmus, Chlorella, Pondorhina, Euridina, etc are living in sewage water. They are mainly useful to clean the water by realizing Oxygen. They also modified the carbonate material in the water into N, P, K fertilizers.
16. Algae as research material:
In biological research algae are useful because of their rapid growth, brief life span and easy mode of cultivation. Chlorella, Scenedesmus and Anacystis are used in investigations in photosynthesis. Blue-green algae are used in studies on nitrogen fixation. Researches in Genetics and Cytology are carried out on Acetabularia.
17. Algae in Space:
Chlorella and Synechococcus are finding application in space ships and nuclear submarines as oxygen regenerating and food and water recycling organisms.
Harmful aspects of Algae
Some algae species like Microcystis, Lyngbya are develop water blooms in water areas. They secrete toxic materials into water. That they polluted the water.
The algae, Cephaleuros virescence causes for red rust tea in tea plant.
Some algae species are caused for some skin diseases.
Dianophlagellate is caused for the death of fishes in water.
By Leshan Wannigama