The Economic Importance of Algae

While algae are not actually true plants, they share several similarities, for example, the presence of chlorophyll and oxygen production through photosynthesis. 

The word algae is derived from the Latin word for 'seaweeds'. Algae can be described as simple, nonflowering, plant-like organisms which range in size from single-celled microalgae to giant, multicellular forms like kelp or seaweed (macroalgae).

There are mainly four types of Algae which are:

 1. Blue-green algae

2. Green Algae 

3. Red Algae 

4. Brown Algae

Algae plays a significant role in various aspects, such as industrial use, food, agriculture, space, and medicines. 

1.0Algae as Food and Fodder

Algae play a crucial role as both food and fodder. They are a vital source of organic nutrients for aquatic animals, supporting pisciculture. 

Some algae, like Diatoms and green varieties, directly serve as food for fish. In turn, these aquatic creatures become a supplementary food source for humans.

Around the world, various algae types are part of human diets such as Blancmanges dishes, Salad, Kombu and soup. 

Spirogyra and Oedogonium are popular in India, while Ulva is significant in Europe. 

Algae, like Porphyra, are rich in vitamins B and C, widely consumed in England, China, Japan, and South Korea. Irish moss was historically widely used in Western Europe.

In China and Japan, seaweeds, including Kombu and Porphyra, constitute about 25% of daily diets, providing proteins, fats, and vitamins A, B, C, and E.

Additionally, algae contribute to commercial vitamins A and D production. They are also used as fodder, with some countries processing seaweeds into cattle feed, enhancing milk production in cattle.

• Chlorella-Chlorella is high in Riboflavin (vitamin B2), Thiamine (vitamin B1) and Iron.
• Chondrus crispus (Irish moss) – Popular dish Blancmanges
• Ulva – Salad in Japan
• Porphyra – used as food having protein and vitamins B &C.
• Laminaria - Kombu food in Japan (Carbohydrate-rich)
• Rhodymenia - dulse food
• Monostroma – use as aonori in Japan.
• Spirulina is the richest source of protein.
• Scenedesmus- equivalent to skimmed milk
• Nostoc – used as soup in China.
• Spirogyra- used in South India.
• Fucus and laminaria are good sources of iodine.
• Bromine found from Polysiphonia species.

2.0Algae Uses in Space Travel

Chlorella (space algae) Scenedesmus and Synchococcus are used as food sources for space travelers. These algae are very rich in proteins (single cell protein) and multiply rapidly and thus synthesize a rich harvest of food utilizing carbon dioxide and liberating sufficient oxygen as a byproduct for use.

3.0Role of Algae in Medicines

• Algae have a rich history in medicinal applications dating back centuries. Ancient Chinese literature mentions the use of Laminaria sp. to treat goitre, benefiting from the iodine content in brown algae.
• Laminariales members have served as surgical tools and aids during childbirth to expand the cervix.
• Chlorellin, an antibiotic, is derived from Chlorella. 
• Red algae contribute to agar, a vital ingredient in pharmaceuticals for pills and ointment production. 
• Carrageenan and alginic acid, found in algae, act as blood coagulants.
• Algal extracts from Codium, Alsidium, and Durvillea have proven effective as vermifuges. In the Unani medicine system, various algae are employed to address lung, kidney, and bladder ailments. 
• Cladophora and Lyngbya extracts exhibit antiviral properties, contributing to the diverse medicinal uses of algae.

4.0Role of Algae in the Origin of Petroleum And Gas

• Petroleum and gases, widely recognized as fuels, trace their origins to organic matter in marine environments. Plankton, through photosynthesis, captured solar energy and transferred it to marine animals as food. Organic compounds from both plankton and marine life accumulated in shallow ocean floor mud deposits. 
• Over time, sedimentary processes buried these materials in an oxygen-free environment, transforming them into oil and gas. 
• The natural gas linked with oil, primarily methane, results from the activity of methane-producing bacteria acting on organic compounds of Diatoms and Cyanobacteria. This process contributes to the formation of valuable energy resources beneath the ocean floor.

5.0Algae as a Sewage Disposal

• Algae, including Chlamydomonas, Chlorella, Scenedesmus, and Euglena, play a crucial role in sewage disposal. In sewage tanks, these algae offer an efficient, swift, and economical method of transforming sewage into a valuable, odorless fertilizer. 
• The tanks forster algae growth at the expense of sewage, where the algae, through photosynthesis, generate oxygen for microorganisms. These microorganisms, in turn, decompose the organic components of the sewage.

6.0Algae in Agricultural Fields

• Blue-green soil algae, such as Anabaena and Nostoc, play a crucial role in agriculture by fixing nitrogen in the soil.
• Studies by P. K. De and R. N. Singh have confirmed their significance in nitrogen fixation, particularly in rice fields and the reclamation of barren lands.
• Cyanobacteria, including Oscillatoria, Nostoc, Spirulina, and Cylindrospermum, neutralize soil alkalinity, enhancing soil fertility. 
• In addition to this, seaweeds, like large kelps and red algae, have been utilized for centuries as biofertilizers, particularly in coastal regions. These seaweeds, rich in potassium, are beneficial for crops like potatoes and turnips.
• In some regions, seaweeds are burned, and their ashes are used as a common agricultural practice. 
• In Rajasthan, Spirulina and Anabaena blue-green algae are commercially cultured in Sambhar Lake, serving as valuable manure for local farmers. Concentrated liquid seaweed extracts are also sold as fertilizers and insecticides
• Additionally, ground forms of Lithothamnion, Lichophyllum, and Chara are used instead of lime in certain countries. In fish culture, algae such as chlorella also help to aerate water by removing carbon dioxide and restoring supply of oxygen in photosynthesis. 

7.0Algae in Industries

Algae are valuable in industries, providing key products like:

• Agar-agar :Derived from red algae like Gelidium and Gracilaria, agar is used in microbiology labs, pharmaceuticals, and various food products like bread, pastries, and jellies.
• Algin: Found in brown algae like Ascophyllum and Laminaria, algin is used in thickeners, cosmetics, textiles, plastics, and artificial fibers. It's a key component in emulsifiers for confectionery, dental products, paints, and ice creams.
• Carrageenin: Extracted from red algae like Chondrus crispus, carrageenin is used as an emulsifying and stabilizing agent in food, textiles, pharmaceuticals, and cosmetics.
• Diatomite: Composed of fossilized diatoms, diatomite is used in oil refineries, sugar industries, insulation, construction, soundproofing, and even in toothpaste.
• Kelp: Brown algae like Laminaria are a source of iodine, soda, and potash, with Japan alone producing around 100 tons of iodine annually from kelps.