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CULTURE OF BLUE GREEN ALGAE AND ITS

IMPORTANCE

Introduction: Blue-green algae, also known as Cyanobacteria, are a

group of photosynthetic bacteria that many people refer to as "pond scum."

Blue-green algae are most often blue-green in color, but can also be blue,

green, reddish-purple, or brown. Blue-green algae generally grow in lakes,

ponds, and slow-moving streams when the water is warm and enriched with

nutrients like phosphorus or nitrogen.

When environmental conditions are just right, blue-green algae can grow

very quickly in number. Most species are buoyant and will float to the

surface, where they form scum layers or floating mats. When this happens,

we call this a "blue-green algae bloom." In Wisconsin, blue-green algae

blooms generally occur between mid-June and late September, although in

rare instances, blooms have been observed in winter, even under the ice.

Many different species of blue-green algae occur in Wisconsin waters, but

the most commonly detected include Anabaena sp.,

Aphanizomenon sp., Microcystis sp., and Planktothrix sp. It is not always the

same species that blooms in a given water body, and the dominant species

present can change over the course of the season.

Nutrient composition: Blue-green algae are widely considered to

be a whole food for the skin and body.

It contains a broad spectrum of nutrients, including essential fatty acids,

vitamins, minerals, proteins, amino acids, and enzymes.

Blue-green algae contains : vitamin A (beta-carotene), vitamin C

(ascorbic acid), choline, folic acid, thiamin (vitamin B1), riboflavin (vitamin

B2), niacin (vitamin B3), pantothenic acid (vitamin B5), pyridoxine (vitamin

B6), cobalamin (vitamin B12), biotin, vitamin E, and vitamin K.

It also contains several essential trace minerals, including calcium, chloride,

chromium, copper, iron, magnesium, manganese, phosphorus, potassium,

sodium, and zinc.

Blue-green algae are one of the very few botanical sources for all twenty

essential amino acids.

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Properties of Blue Green Algae: A simple organism, blue

green algae lacks the distinct organs like leaves and roots of land plants, and

has some characteristics of bacteria. They are a rich source of probiotics,

useful to replace good bacteria lost through the use of antibiotics in humans.

They are also prized for their chlorophyll content. The structure of

chlorophyll is very similar to that of hemoglobin, making the nutrients in

blue green algae easily assimilated by humans. History of BGA: Blue green alga was used by the ancient Egyptians

as colorful eye shadow. The largest and most complex marine forms of

algae, seaweeds are an important source of food in many countries. Also,

called vegetable plankton, blue green algae grows throughout the world.

Culture (Spirulina):

Systematic position

Spirulina is a blue green algae belonging to ---

Class: Cyanophyceae

Order: Nostocales

Family: Oscillatoriaceae

The research work in India with regard to utilization has largely been

carried out with 2 species.

1. Spirulina platensis & 2. S. fusiformis

BGA in aquarium

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Culture of BGA:

1. The commercial design of spirulina culture system comprises a network

of cement raceways with paddle-wheel agitation to prevent algal

accumulation at the surface & to ensure uniform distribution of nutrients,

with modification in terms of vertical reactors, tubular reactors etc.

2. The outdoor culture parameters are cement raceways or vats preferably

with a mid-rib for facilitating water circulation.

3. Culture medium depth 15-20 cm, agitation 20cm/sec,.

4. Temperature 25-35 °C, light intensity 20-30k lux , hardness 120 mg/l,

5. PH 9-11 provided with nutrients. Zarrouk’s medium is used in indoor

culture.

6. Pure culture may be maintained in Zarrouk‘s medium in a room provided

with a simple algal culture chamber consisting of rack with 2-4 tubes.

7. The culture volume is gradually upgraded to the level of outdoor cisterns

where mass culture medium may be used.

8. Provision of half of the quantity of sodium bicarbonate (9 g/l) or carbon-

di-oxide bubbling is suggested.

9. Several low cost inputs like biogases’ slurry have been tried with

measurable success, which may be incorporated.

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10. Individuals can maintain about 100 m² of area in the form of cement

vats 15-20 no. to whom the central unit of the village could supply nutrient

inputs on a weekly basis & in turn collect the spirulina produced.

11. A continuous culture method of harvesting & nutrient dosing is practiced

& the vats are cleaned after 4-6 months.

12. While screens made of bolting silk cloth of size (0.75×0.75 m) would be

convenient for harvesting the alga from tanks maintained by individuals on a

bi weekly basis, a pump & a rolling screen may be employed for mechanical

large-scale systems.

13.Contamination is minimal due to highly alkaline pH levels.

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14. The wet biomass is sun dried on polythene sheets by the indivisual or

spray-dried in mechanised units for marketing purposes.

15. The culture of spirulina needs to be carried out with almost care with

spray-drying the product is for human consumption.

Natural production: Most commercial production systems are based on

shallow raceways in which spirulina cultures are mixed by a paddle wheel.

However,there are still some examples of spirulina being harvested

commercially from naturally occurring populations.

For growth of BGA

1.Find a sunny spot where one can grow blue-green algae. Although it is a

bacteria, it behaves much like a plant in that it requires at least six hours of

sunlight a day to grow and thrive. Set down a light or clear container to

allow sunlight to reflect from the bottom of it.

2.Fill the container with water from a pond, lake or spring. It grows best in

warm, stagnant water, but it must be from a natural outdoor source;

therefore, it will not grow in tap water. The reason one need water from a

pond or lake is that it contains phosphorus, nitrogen and other particles

necessary for it to grow.

3.Use a pond skimmer to remove any algae that floats to the top of the

container. Doing so allows sunlight to permeate all the water throughout the

entire container, which promotes continued growth. It also maintains steady

water temperatures and oxygen levels.

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Instructions should be followed:

1. Grow blue-green algae in summer or early fall when waters are warm.

Algae blooms are less likely to grow in cold winter.

2 .Make sure the water is rich in nutrients-nitrogen or phosphorus and the

waters are calm and warm.

3. Watch blue-green algae multiply in abundance in high temperatures and

lots of sunlight.

4. Increase the chances of growing blue-green algae by making sure the

water is stagnant (no movement) like in a dam or stopped-up river. Slow

moving water is good for algae growth.

5. Check out portions of lakes where sediments are churned up after a

hurricane. This type of storm-water carries ample amounts of nutrients that

blue-green algae thrive on.

Harvesting and processing: Spirulina harvesting, processing

and packing has eight principle stages:

1. Filtration and cleaning : A nylon filter at the entrance of the water

pond is needed.

2. Pre-concentration: To obtain algal biomass which is washed to

reduce salts content.

3. Concentration: To remove the highest possible amount of interstitial

water (located among the filaments).

4. Neutralization: To neutralize the biomass with the addition of acid

solution.

5. Disintegration:To break down trichomes by a grinder,

6. Dehydration by spray-drying: This operation has great economic

importance since it involves about 20–30 percent of the production

cost,

7. Packing: It is usually in sealed plastic bags to avoid hygroscopic

action on the dry spirulina,

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8. Storage: Stored in fresh, dry, unlit, pest-free and hygienic

storerooms to prevent spirulina pigments from deteriorating.

Application of BGA:

1. It is a health food & nutritional supplement for the human being has

unlimited scope in the future.

2.It has been shown to be a therapeutant with regard to several diseases

like night blinders , anemia , glucomia , cholesterol accumulation ,pancreatis

etc.

3. Its antioxidant properties have been attributed with cancer prevention

possibilities.

4. Studies showed higher fish growth rates with spirulina.

5.Pigmentation of ornamental fishes & prawn larvae has commercial

significance.

6. New areas of spirulina application are with regard to extraction of

valuable enzymes like phosphoglycerokinase specific for ATP determination,

superoxide dismutase required in genetic engineering & phycobillin used in

immunodiagnostics.

7. The effect of spirulina on the nourishment of skin have paved the way

for cosmetic formulations using this alga.

8. Spirulina with regard to human/animal nutrition & therapy command a

high export value as also import substitution.

Concerns Associated With BGA:- 1. Blue-green algae discolored water, reduced light penetration, taste

and odor problems, dissolved oxygen depletions during die-off, and

toxin production.

2. Discolored water is an aesthetic issue, but when blue-green algae

reach bloom densities, they can actually reduce light penetration,

which can adversely affect other aquatic organisms both directly

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(e.g., other phytoplankton and aquatic plants) and indirectly (e.g.,

zooplankton and fish that depend on phytoplankton and plants).

3. Blue-green algae blooms can be quite smelly, and though it is

recommended that people never drink raw water, blue-green algae

have been known to affect the taste of drinking water that comes

from surface waters experiencing a bloom.

4. When a blue-green algae bloom dies off, the blue-green algae cells

sink and are broken down by microbes. This breakdown process

requires oxygen and can create a biological oxygen demand.

Increases in biological oxygen demand result in decreases in oxygen

concentration in the water, and this can adversely affect fish and

other aquatic life, and can even result in fish kills.

Summary:

Blue-green algae are very small organisms and can be seen with the

aid of a microscope as single cells, accumulations of cells (colonies) or

filaments of cells (trichomes).Their main photosynthetic pigment is

phycocyanin, which is blue in colour. These bacteria also contain

chlorophyll a and carotenoids. Some contain the pigment phycoythrin,

giving the bacteria a red or pink colour. BGA are photosynthetic and

therefore autotrophic. They reproduce by binary fission. Blue-green

algae is widely considered to be a whole food for the skin and

body.There are fewer than twenty substances that have been

discovered that are believed to be required vitamins for human

survival, and blue-green algae contains thirteen of them.

Conclusion:

Spirulina culture, in fact is being used as a tool to reduce

pollution from wastewater like domestic sewage.Achieving the twin

objectives of pollution reduction & nutrient harvest in the form of a high

quality protein. . This is also serves for certain phermaceutical products involving

extraction procedures.

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. Spirulina is a natures gift among the aqua product, whose potential can be

harnesed for better nutrition, health economy & environment.

References:-

1.www.google.com

2. Yahoo Groups; Spirulina

Erythrocytes

http://www.biochemj.org/bj/369/0429/bj3690429.ht

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3. www.wikipedia.com

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