Blue-Green Algae

Blue-green algae are popularly known as Cyanobacteria. They are generally green and often become bluish when the scum starts dying. You must have seen them growing on the surface of water bodies. Excessive growth of cyanobacteria may produce toxins and can negatively influence marine ecosystems and humans.

Table of Contents

What is Blue-Green Algae?
Nitrogen Fixation by Cyanobacteria
Optimum Conditions for Blue-Green Algae Growth
Growth Process of Blue-Green Algae
Applications of Blue-Green Algae
Problems Associated with Blue-Green Algae
How to Reduce The Growth of Blue-Green Algae

What is Blue-Green Algae?

Blue-green algae are a class of photosynthetic bacteria that are either made up of single cells or colonies. However, only chlorophyll a, a green pigment, and phycobilin, xanthophylls, and carotenoids are present in blue-green algae.

Furthermore, phycobiliprotein, c-phycocyanin, and c-phycoerythrin are also the chief elements of blue-green algae. Bacteria spontaneously grow in marine or freshwater like rivers, lakes, reservoirs, and dams, where they love to increase. Blue-green algae are buoyant, which means they only float, and their colonies may look like mats on the surface of the body water.

The huge accumulation of blue-green algae results in discolouration and bad odour in the water. When blue-green algae accumulates, it blooms and degrades the water quality. Thus affecting marine animals. Furthermore, if the bloom decomposition starts, it depletes the oxygen level in the water and therefore the death of fish and marine animals takes place.

Nitrogen Fixation by Cyanobacteria

Blue-green algae are involved in the fixation of carbon from carbon dioxide. Blue-green algae generally spread all over the water's surface and sometimes start fixing nitrogen from the atmosphere, called nitrogen fixation. Certain blue-green algae can even fix nitrogen as it consists of nitrogenase, an oxygen-sensitive enzyme.

Optimum Conditions for Blue-Green Algae Growth

When phosphorus and nitrogen are available in water appropriately, blue-green algae grow efficiently.
The contraction ratio must be low between nitrogen and phosphorus.
Stable climate conditions are favourable for the growth of blue-green algae.
Blue-green algae generally grow in cool weather, but warm weather suits their growth and effectively spreads on the water's surface.
Water turbulence must be low.

Growth Process of Blue-Green Algae

Naturally, blue-green algae produce their food via photosynthesis, using oxygen, light and nutrients. Furthermore, cell division proceeds with the help of the sugar they produce. You must have seen the floating greenery while visiting ponds and lakes. Summer is a favourable climate for the spontaneous growth of blue-green algae. Water is warm, and thus effective bloom starts.

Applications of Blue-Green Algae

As a nutrient supplement, blue-green algae is utilised for weight loss.
It controls the cholesterol level.
Boosts immune systems
Produces a small volume of certain minerals and beta-carotene.
Blue-green algae also produce vitamins like C, E and folate.
Certain blue-green algae fertilise rice paddies and fields, contributing to the food supply.
Blue-green algae produce numerous vitamins, growth factors and drug compounds.
Spirula is one of the rich sources of protein taken from blue-green algae.

Problems Associated with Blue-Green Algae

Considered to be negative in most of the cases of human health.
Degrades water and creates an unpleasant odour and taste of water.
Huge impacts on aquatic life.
Depletes the concentration of oxygen supply in water.
Results in high water treatment cost

How to Reduce The Growth of Blue-Green Algae?

It is convenient to decrease the blue-green algae growth in water. Some of the methods are as follows:

Decrease the level of phosphorus and nitrogen in the water bodies. It reduces the growth intensity of the blue-green algae.
Lower the oxygen level in the water.
Decrease the temperature of water and the environment around the water.
Low light

Practice Questions

Q1. Blue-green algae contain

A. Chlorophyll a
B. C-phycoerythrin
C. Xanthophylls
D . All of the above

Ans. D. All of the above.

Blue-green algae contain chlorophyll a, xanthophyll and c-phycoerythrin as their chief elements.

Q2. Blue-green algae can be utilised to produce

A. Vitamins and minerals
B. Proteins
C. Carbohydrates
D. None of the above

Ans. A. Vitamins and minerals

Blue-green algae can produce vitamins like c, e, folate, and minerals.

Q3. Blue-green produce food using

A. Light
B. Oxygen
C. Nutrients
D. All of the above

Ans. D. All of the above

Blue-green algae can produce their food using light, oxygen and nutrients.

Frequently Asked Questions

Q1. Can I take nutrient supplements produced by the blue-green algae on my own?
Answer : No. Nutrient supplements are taken in case of need and are only preferred by your doctor. You can take the blue-green algal nutrient supplements if your consultant suggests you take them.

Q2. Can I see blue-green algae in the ponds nearby?
Answer : Yes. If the climate and water conditions suit the blue-green algae, it must have grown in your nearby pond.

Q3. Can I eat blue-green algae directly from the water?
Answer : No, you cannot eat blue-green algae directly. It is harmful to human beings’ health and may also contain several insects on their dense sheet.