Blue Green Algae - Classification, Characteristics, Economic Importance

Blue Green Algae: Blue-green algae, also known as Cyanobacteria, are photosynthetic bacteria that can exist as single cells or colonies. They contain a green pigment called Chlorophyll a and other pigments such as carotenoids and phycobilins. These bacteria are commonly found in marine and freshwater environments, including dams, rivers, reservoirs, lakes, and hot springs.

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Blue Green Algae Classification

Mammary Glands

Blue Green Algae Characteristics

1. Prokaryotic Nature: Blue-green algae are unicellular or filamentous prokaryotes, devoid of a membrane-bound nucleus and other organelles typical of eukaryotic cells.
2. Photosynthetic Pigments: These organisms contain chlorophyll a, the primary photosynthetic pigment. Additionally, they possess other pigments like phycocyanin and phycoerythrin, contributing to their distinctive blue-green hue.
3. Cell Wall Composition: Blue-green algae feature a firm cell wall composed of peptidoglycan, a hallmark of bacterial cells.
4. Habitats: They are predominantly found in freshwater bodies like lakes, ponds, rivers, and streams, although they can also thrive in marine environments and damp terrestrial locales such as soil and rocks.
5. Nitrogen Fixation: Certain species of blue-green algae can fix atmospheric nitrogen, converting it into a utilizable form for plants and other organisms.
6. Colonial Forms: Some variants can form colonies or filaments, which may consist of multiple cells.
7. Toxin Production: Specific species have the potential to produce toxins, particularly in conditions of nutrient pollution and high temperatures. This toxin production can lead to harmful algal blooms (HABs) and harm aquatic life and human health.
8. Ecological Significance : Blue-green algae are pivotal in ecosystems as primary producers, furnishing sustenance and oxygen to other organisms. They also play a crucial role in nutrient cycling, particularly through nitrogen fixation.

Okazaki Fragments

Blue Green Algae Examples

• Nostoc: This genus of cyanobacteria forms bead-like strands of cells clumped together in a gelatinous mass. Nostoc masses can vary in size from microscopic to walnut-sized and are typically found on soil or floating in still water.
• Oscillatoria: Oscillatoria is a genus of cyanobacteria found in freshwater habitats, including hot springs. They appear as trichomes, which are hair-like filaments that can be blue-green, brown, or red in colour.
• Microcystis aeruginosa: This single-celled cyanobacteria is found in surface waters. It can form large blooms that discolour the water and produce toxins harmful to humans and animals.
• Spirulina : Spirulina is a filamentous cyanobacteria sometimes sold as a health food supplement. It is a rich source of protein, vitamins, and minerals.
• Anabaena: Anabaena is a filamentous cyanobacteria capable of nitrogen fixation from the air. It is found in both freshwater and saltwater habitats. Certain species of Anabaena can produce toxins harmful to humans and animals.

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Blue Green Algae Prokaryotic or Eukaryotic

Why Cyanobacteria is called as Blue Green Algae

Sexual Reproduction in Flowering Plants

Economic Importance of Blue Green Algae

1. Natural Fertilisers: Certain species of blue-green algae have the extraordinary ability to fix atmospheric nitrogen. Nitrogen is an essential nutrient for plant growth, and these algae can convert it into a form usable by crops. This reduces the need for chemical fertilisers, promoting sustainable agriculture. Species such as Nostoc, Oscillatoria, Scytonema, and Spirulina are commonly used as biofertilisers in rice fields. They form a symbiotic relationship with rice plants, providing them with nitrogen and benefiting from the organic matter produced by the rice.

2. Food Source: Some species of blue-green algae are cultivated as food! Spirulina is a particularly popular example, valued for its complete protein profile and high vitamin content. It is consumed as a dietary supplement in powder otablet form and can also be added to smoothies or snacks.
3. Biofuel Potential: Blue-green algae are being investigated as a promising source of biofuel. Their rapid growth rates and ability to thrive in various conditions make them attractive candidates for renewable fuel production. Research is ongoing to enhance their cultivation and conversion processes for large-scale biofuel production.
4. Medicinal Applications: Certain strains of blue-green algae are being studied for their potential medicinal properties. They may be beneficial in areas such as immune system support, wound healing, and even cancer treatment. While research is still in its early stages, the prospects are promising.
5. Wastewater Treatment: Blue-green algae can contribute to wastewater treatment by absorbing nutrients such as nitrogen and phosphorus, which can lead to algal blooms in natural water bodies. This helps to purify the wastewater while also producing biomass that can be utilised for various purposes.