Economic Importance of Algae
Beneficial roles of algae
Harmful aspects of Algae
1.Primary Producers:
2. Algae as Food
3. Algae as fodder
4. Algae in Agriculture
5. Algae in Industries
6. Algae in Sewage Disposal
7.Algae and Research
8.Algae Producing, Growth
Hormones
Department of Plant Biology and Biotechnology
G.V.N. College, Kovilpatti.
Beneficial roles of algae
1.Primary Producers:
2. Algae as Food
3. Algae as fodder
4. Algae in Agriculture
5. Algae in Industries
6. Algae in Sewage Disposal
7.Algae and Research
8.Algae Producing, Growth Hormones
Department of Plant Biology and Biotechnology
G.V.N. College, Kovilpatti.
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.
Department of Plant Biology and Biotechnology
G.V.N. College, Kovilpatti.
Beneficial roles of algae
1.Primary Producers:
2. Algae as Food
3. Algae as fodder
4. Algae in Agriculture
5. Algae in Industries
6. Algae in Sewage Disposal
7.Algae and Research
8.Algae Producing, Growth Hormones
Department of Plant Biology and Biotechnology
G.V.N. College, Kovilpatti.
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.
Department of Plant Biology and Biotechnology
G.V.N. College, Kovilpatti.
2. Algae as Food
•Many freshwater and marine algae have been utilized
as a direct source of food.
•Algae are rich in proteins, carbohydrates, oils,
vitamins A,B,C and E and minerals
Example
Cyanophyceae (or) Blue green algae – Nostoc & Spirullina
Brown Algae – Sargassum
Green Algae – Chlorella
3. Algae as fodder
Many sea-weeds are directly used as feed for cattle, poultry and aquatic
organisms. Example: Laminaria and Fucus
Sea-weed meal increases the egg-laying capacity of poultry.
4. Algae in Agriculture
a. Algae as Green Manure
Sargassum, and Gracilaria are commonly used as green manures in
agriculture.
Sea weed manure increases the yield of barley, potato, coconut palms,
citrus, etc.
b. Algae as Nitrogen Fixers (Biofertilizers)
Many blue-green algae have the ability to fix the atmospheric nitrogen in
the soil.
e.g.: Nostoc, Anabaena, Spirulina
c. Algae used for Reclamation of Soils
Saline and alkaline soils can be converted into productive soil by growing
some blue-green algae.
Department of Plant Biology and Biotechnology
G.V.N. College, Kovilpatti.
5. Algae in Industries
In industries, many algae have been used as sources for the
extraction of commercial products such as agar-agar,
carrageenin, algin and diatomite.
a. Agar-agar
"
Agar agaf is a gelatinous, polysaccharide obtained from some
red-algae such as Gelidium, Gracilaria and Gigqrtina.
Agar-agar is used for making artificial culture media for
algae, fungi, bacteria and plant tissues in biological
laboratories.
It is used as emulsifier in the preparation icecreams, fruit
jellies and dairy products.
It is used as sizing agent in leather and textile industries.
It is used in paper making.
Department of Plant Biology and Biotechnology
G.V.N. College, Kovilpatti.
b. Algin
Alginic acid is extracted from Laminaria,
Macrocystis andAscophyllum.
1. Alginic acid is used in making antibiotic
capsules like aureomycin.
2. It is used as painting pastes in textile industry.
3. It is used as thickeners in cosmetics,
pharmaceutical products, paints and polishes.
4.Alginates are used as emulsifiers in
toothpaste,ice .cream etc.
5. They are also used in the production of
plastics, rubber and artificial fibres.
Department of Plant Biology and Biotechnology
G.V.N. College, Kovilpatti.
Food scientists (not cooks -- food scientists make
processed foods) use these substances for four main
reasons:
• They thicken things: Ice cream, marshmallow fluff,
pancake syrup, etc., all benefit from thickening.
• They emulsify things: They help liquids to stay mixed
together without separating.
• They change the texture: Generally, a gum will make
something thicker or chewier.
• They stabilize crystals: A gum might help prevent sugar
or ice from crystallizing.
c. Carrageenin
Carrageenin is a mucilaginous substance extracted from red alga
Chondrus crispus and Gigartina.
It is used in food industry, textiles, pharmaceutical industry and
leather industry.
d. Diatomite
Diatomite is a rock like deposit formed by the
deposition of siliceous cell walls of diatoms over millions of
years back.
Some of the uses of diatomaceous earth are1. Diatomite is used as filtering medium for oils and solvents.
2. It is used as cleaning agent for some solvents.
3. It catalyses dehydrogenation of vegetable oils.
4. It is used in the insulation of refrigerators, boilers, pipes, etc.
Department of Plant Biology and Biotechnology
G.V.N. College, Kovilpatti.
c. Carrageenin
Carrageenin is a mucilaginous substance extracted from red alga
Chondrus crispus and Gigartina.
It is used in food industry, textiles, pharmaceutical industry and
leather industry.
d. Diatomite
Diatomite is a rock like deposit formed by the
deposition of siliceous cell walls of diatoms over millions of
years back.
Some of the uses of diatomaceous earth are1. Diatomite is used as filtering medium for oils and solvents.
2. It is used as cleaning agent for some solvents.
3. It catalyses dehydrogenation of vegetable oils.
4. It is used in the insulation of refrigerators, boilers, pipes, etc.
Department of Plant Biology and Biotechnology
G.V.N. College, Kovilpatti.
5. 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.
Department of Plant Biology and Biotechnology
G.V.N. College, Kovilpatti.
6.Algae and Research
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.
7.Algae Producing, Growth Hormones
Growth hormones like Indole acetic acid (IAA) is extracted
from algae like Laminaria, Fucus, etc.
8.Algae in Space:
Chlorella and Synechococcus are finding application in space
ships and nuclear submarines as oxygen regenerating and
food and water recycling organisms.
Department of Plant Biology and Biotechnology
G.V.N. College, Kovilpatti.
Harmful aspects of Algae
 Some algae species like Microcystis, Lyngbya are develop
water blooms in water areas.
 They secrete toxic materials into water and polluted the
water.
 Some algae species are caused for some skin diseases.
Dianophlagellate is caused for the death of fishes in water.
Department of Plant Biology and Biotechnology
G.V.N. College, Kovilpatti.