2. SYNOPSIS
Beneficial use.
• Primary Producers
• Algae asFood
• Algae as Fodder for cattle
• Industrial Uses
• Medicinal Uses
• Algae & Nitrogen Fixation
• As Fertilizer
• Algae in SewageDisposal
• Algae in LandReclamation
• Drinking Water
• Algae Biological Research
Harmful Use
1 Contamination of WaterReservoirs
2. WaterBlooms
3. Eutrophication
4. Diseases In Human Beings
5. ParasiticActivities
3. ALGAE
Algae are photoautotrophic that can
prepare their own food and they
produce oxygen during photosynthesis.
Algae are ubiquitous. Majority of
algae are abundant in stagnant
waters.
5. 1. Primary Producers
Algae are the main oxygen producers in aquatic areas.
They are also useful in decreasing water pollution by
releasing oxygen.
10% of total photosynthesis carried out by plants is
carried out by the algae.
6. 2. Algae asFood
Algae species are used as food in several countries and in
several forms. Japan is one of the countries where algae
are used as major food ( Porphyra tenara Pheophyceae).
Algae species have rich in proteins, vitamins (A, B, C
and E), lipids, and minerals.
Algae like Laminaria, Alaria, Arthrothamu are commonly
used as vegetables.
Chlorella is utilized for making pastries, cakes,
sandwiches.
7. 3.Algae as fodder for cattle
• Rhodymenia palmata is
used as food for sheep in
Narvey.
• Laminaria saccharina,
Pelvitia, Ascophyllum,
etc. species are used as
food for cattle.
8. 4. Industrial Use
a. Algae as Source of Iodine
• The marine algae are rich in iodine
and several other important minerals.
• By feeding the milk cattle and hens
with algae, iodine quantity of the milk
and eggs may sufficiently be
increased.
9. b. Use of Algae asDiatomite
• Diatomite is fossilized remains
of diatoms. Diatoms are single-
celled aquatic algae which are in
the form of petri dish.
• It is used in car paint, roof
insulation, wall insulation,
cosmetics and bath products.
11. d. Use ofAlgae asAgarAgar
• It is a jelly like substance
obtained from algae.
• It is used in desserts and
• By using agar, microorganisms can
be cultured.
• other cooking. It is also used to
thicken soups and sauces.
12. e. Use as Algin
• Algin is obtained from different algae.
• It is used in adhesive structure in
artificial silk.
• It is used in paints and many
pharmaceutical products.
• It is used in ice creams.
• natural and synthetic rubbers
13. 5. Medicinal use
• Some algae yield antibiotics Chlorellin is
obtained from green alga Chlorella, that inhabits
the growth of certain bacteria.
• Because of high iodine contents, Brown algae is
used in manufacture of various goiter medicines.
• Spirogyra is used for cleaning of optical
instruments.
14. 6. Role in Nitrogen Fixation
• Algae plays in important role in
nitrogen fixation.
• They converts molecular nitrogen
into simpler form such as nitrates
& nitrites.
• A high rice yield has obtained
when the rice field were
inoculated by nitrogen fixation.
15. 7. Algae asFertilizer
• Due to presence of P, K, Ca, and
some trace elements , the sea
weeds are used as fertilizers.
• Chara is used to overcome
calcium deficiency in the fields.
• Fucus is used as manure.
16. 8. Algae in Sewage Disposal
• The effective disposal of sewage
requires oxygen and this oxygen is
brought about by the algal members
present in the sewage like
Chlamydomonas, Chlorella etc.
• The oxygenation by algae also
helps to avoid unpleasant odour
coming out of sewage bodies.
17. 9. Algae in Land Reclamation
• Algae act as binding agent.
• Algae help in reducing the pH of
alkaline soils and increasing the
water holding capacity of these
soils.
18. Drinking Water
Nitzschia palea, a diatom is cultivated in the water to make is useful
for drinking purpose because this alga secrets substance.
Algae In Biological Research
Due to eassy availability of algae, some significant experimental work
has been carried out on them. Most of the photosynthetic experiment
have been performed with the help of Chlorella other algae such as
Acetabularia.
20. 1. CONTAMINATION OF WATER RESERVOIRS
• The algae grows abundantly in water reservoirs meant for domestic
purposes.
• This affects the filtration process and brings bad taste to water due to
decay of dead algal plants.
• Such algae include members of cyanophyta and chlorophyta.
21. 2. WATER BLOOMS
• Sometimes algal plants grow
abundantly and form quit apparent
bodies called water blooms.
• These bodies deplete the oxygen contents
of the water during night time.
• Emit bad smell and secrete certain
poisonous substances harmful to
aquatic animals.
22. 3. Eutrophication
• Algae causes eutrophication in ponds and lakes. It causes
death of aquatic animals.
• The death of cattles occur by drinking the infected water.
• Due to thick layer of algae on surface of water,
photosynthesis does not occur.
23.
24. 4. DISEASES IN HUMAN BEINGS
• The contaminated water causes stomach disorder in
human beings.
• Similarly some algae are responsible for respiratory
disorders, skin diseases and other algae causes allergies.
25. 5. PARASITICACTIVITIES
• Some algae are parasites on other plants and animals
as well.
• Most of these belong to the Rhodophyta (red algae).
26. CONCLUSION
• Algae are simple autotrophic organisms and from simple inorganic
molecules such as carbon dioxide they produce complex organic
compounds using energy from light or inorganic chemical reactions.
• Although algae grows at a fast rate and good producers of lipids in
comparison to other oil sources, harvesting the algae and extracting the
lipids is a challenge to the commercial scale development of algae.
• It helps in maintaining the health of the marine ecosystem because algae are
naturally absorbent of carbon dioxide and also provide oxygen to the water.
• Algae are rich in minerals and vitamins. So they also used as liquid
fertilizer which helps in the repairing level of nitrogen present in the soil
27. REFERENCE
• Botany by Y.D. TIAGI
• Microbiology by R.P.Singh
• Microbiology by Dubey and Maheshwari
• Slide Share
