3. CYANOBACTERIA
•They are photoautotrophs
•On the basis of their size, cell structure, presence of
murein, 70S Ribosome's and other features the
cyanobacteria are prokaryotes.
•They occur as unicellular, colonial or filamentous
organisms.
•They are gram negative bacteria.
•That use water as the hydrogen donar and perform oxic
photosynthesis.
•Some are motile by gliding on solid surface.
4. • The photosynthesis is localized in flat, membranous
vesicles, the thylakoids.
• The membranes of thylakoid contain chlorophyll a, ß-
carotene, oxocarotenoids and phycobili proteins.
• Many cyanobacteria possess gas vacuoles, which are
involved
• The various pigments determine the colour of the
organisms.
5. Blue green algae:
• It is a widely distributed group of photosynthetic
organisms of the kingdom cyanobacteria, it can fix
atmospheric nitrogen.
• It can be considered as simple aquatic plants that
occur naturally in habitats such as rivers, lakes, damp
soil, tree trunks, hot springs and snow.
6. Five orders of cyanobacteria are;
1. Chrococcales
2. Pleurocapsales
3. Oscillatoriales
4. Nostocales
5. Stigonematales
8. Species of blue green algae
Nostoc:
Phylum:cyanobacteria
Order:harmoganales
Sub order:nostocales
family:nostocaceae.
• Nostoc environment are diverse and widespread over
the globe.
• Isolates have been found in fresh water, soils, and
both extremely cold and extremely acid habitats.
• They are found in gelatinous colonies, composed of
filamentous called trichomes surrounded by a thin
sheath.
9. • It may also grow symbiotically within the tissues of
plants, such as the aquatic fern or hornworts, provide
nitrogen to its host.
• They are photosynthetic prokaryotes that carry out
oxygen evolving photosynthesis.
10. Anabaena:
Kingdom: Bacteria
Phylum: Cyanobacteria
Order: Nostocales
Family: Nostocaceae
Genus: Anabaena
• It is a filamentous BGA, they wide spread in fresh
water and damp soil.
• The cells are ovoid or barrel shaped.
• Anabaena possess heterocysts and can also develops
akinites
11. • Certain sp. Are in symbionts in higher plants
E.g: Anabaena azollae in water fern.
• They provide nitrogen to rice crops in flooded paddy
fields adding up to 40kg bound nitrogen per ha/yr.
• Anabaena helps to release soil bound phosphorus.
12. Tolypothrix
Kingdom: Bacteria
Phylum: Cyanobacteria
Order: Nostocales
Family:Microchaetaceae
Subfamily: Tolypotrichoideae
Genus: Tolypothrix
• The cells are long and cylindrical or short and barrel
shaped.
• The cells are blue green, olive green, yellow or red in
colour and some times have granules
13. • the filaments are covered by musilage.
• Young filament are long with hetrocysts at the base
and free apical ends.
• The heterocysts are spherical, cylindrical or discoid in
shape and have 1-2 pores at their base.
• Akinites are rarely observed.
14. Scytonema
Kingdom: Bacteria
Phylum: Cyanobacteria
Order: Nostocales
Family:Scytonemataceae
• They are gram negative, oxygenic, photosynthesis,
filamentous cyanobacterium.
• Cells are divide in the tips of the filaments.
• The genus is considered to be one of the most
primitive autotrophic organism on the planet; they are
credited with converting earth atmosphere from an
oxygen free to an oxygen rich environment.
15. • Scytonema also produce bioactive compounds
including plant growth regulators.
16. Mass production of BGA:
• For cultivation of cyanobacterial biofertilizers, the
regional specific strains should be used.
The following methods are used for mass
cultivation,
1. Cemented tank method
2. Shallow metal troughs method
3. Polythene lined method(its most suitable for small
and marginal farmers for the preparation of
biofertilizers)
4. Field method.
17. In polythene lined method,
1. Prepare the cemented tank, shallow trays of iron
sheets or polythene lined pits ion an open area, width
of tanks or pits should not be more than 1.5m.
2. Transfer 2-3kg soil and add 100g superphosphate
water the pit to about 10cm height, mix lime to adjust
the pH.
3. Add 2ml of insecticide to protect the culture from
mosquitoes mix well and allow to settle down soil
particles.
4. When water becomes clear, sprinkle 100g starter
culture on the surface of water.
18. • When temperature remains around 35-40˚c during
summer, optimum growth of cyanobacteria is
achieved.
• The water level is always maintained about 1 cm
during this period.
• After drying the algal mass(mat) is separated from the
soil that forms flaks.
• It is collected ,powdered and packed in polythene bag
and supplied to the farmers after sealing the packets.
• The algal flaks can be used as starter inoculam again.
