Cyanobacteria ‘formerly known as’
- Cyano = blue
- Bacteria – acknowledges that they are
more closely related to prokaryotic
bacteria than eukaryotic algae
• cyanobacteria can be found in almost every conceivable
environment, from oceans to fresh water to bare rock to soil.
• They can occur as planktonic cells or form phototrophic biofilms in
fresh water and marine environments,
• they occur in damp soil, or even temporarily moistened rocks
• A few are endosymbionts in lichens, plants, various protists,
or sponges and provide energy for the host.
• Some live in the fur of sloths, providing a form of camouflage.
• Aquatic cyanobacteria are probably best known for the extensive
and highly visible blooms that can form in both freshwater and the
marine environment and can have the appearance of bluegreen paint or scum.
Hot Spring at Yellowstone Park:
The dark color is due to the presence of
Limestone deposit at Yellowstone Park:
The localized areas of green are due to
the presence of Cyanobacteria
A schematic outline of the acquisition, reduction,
and loss of genomes and compartments during
evolution. Black arrows indicate evolutionary
pathways; white arrows indicate endosymbiotic
events in the host cell.
Endosymbiotic event 1 occurred at the origin of
eukaryotes. The proteobacterial endosymbiont
gave rise to mitochondria (the smaller organelles in
the bottom part of the diagram).
Endosymbiotic event 2 occurred at the origin of
Endosymbiotic event 3 represents the secondary
and higher-order endosymbioses giving rise to
numerous algal phyla, as well as apicomplexans
(such as Plasmodium), which have residual plastids,
and to trypanosomes, which have no plastid at all.
Black, filled circles indicate nuclei or nucleomorphs;
ellipses within organelles indicate bacterially
derived genomes, which may be reduced or lost
More than one kind of host cell and of
endosymbiont is involved in the secondary, and in
the higher-order, symbioses. The genome of the
Archaebacterium is not represented in the diagram.
Structural drawing of the
fine structural features of
a cyanobacterial cell.
(D) DNA fibrils;
(G) gas vesicles;
(Gl) glycogen granules;
(Ph) polyhedral body;
(SG) structured granules
• Old 3.5 billion years
• Dominated as biogenic reefs
• During Proterozoic – Age of Bacteria
(2.5 bya – 750 mya) they were wide spread
• Then multicellularity took over
• Cyanobacteria were first algae!
• For BGA production dig a small pit of 6x3x9 feet size in the soil and lay
down a polythene sheet in the pit to check to percolation of water. Large
galvanized steel tray containing soil can also be used for this purpose.
Now 10 Kg soil, 200 gm of super phosphate, 6 litre water and 100 gm BGA
dry flakes containing wooden dust or mother culture of BGA are added
into the prepared pit. If found any pest in the pit, spray melathion
solution ( 1 ml melathion in one litre water) to destroy pests.
• If green algae and diatoms are found in pit, use 0.05% CuSO4 solution
which will kill the green algae. After 12-15 days, a thick layer of BGA will
be found floating on the water surface of the pit. You can easily
collect/harvest the BGA directly from the pit or let the pit dry after water
evaporation and take out dry flakes of BGA and fill it in small polypack
(100-200 gm) for sale.
• By this simple method BGA culture/incoulum can be prepared for use in
the paddy fields. The same methods may be used in the paddy fields for
the large scale productions of BGA culture.
CULTIVATION STOCK CULTURE
•The stock culture for
maintenance of laboratory
culture, 2- 3 mL of a 3 weeks
old cyanobacterial stock
culture was used as
inoculum in 50 mL of
autoclaved BG 11 medium in
150 mL Erlenmeyer flasks.
•The cultivation was carried
out at 20 ±2°C, under
continuous illumination of
8gmol/m2 by cool
•The stock cultures were
maintained for 20-30 days.
CULTIVATION SHAKE CULTURE
Aliquots of 50 mL from the stationary phase stock cultures were used to inoculate
500 mL of autoclaved BG11 medium in 1.5 liter Fehrnbach flasks. These samples
were cultivated at 20 ±20°C, under continuous illumination of 8gmol/m2 by
cool fluorescence lamps. The cyanobacterial cultures were harvested after 4-6
The cells were separated from the medium by centrifugation (4000 rpm/ 10 min/
100C) followed by filtration with filter paper. The biomasses were lyophilized and
stored at -20°C until use while cultivation media were concentrated to 1/10 (v/v) by
rotary evaporation in vacuum at 400°C and extracted immediately with EtOAc
The large scale cultivation was carried out in a 45 literglass fermentor. The fermentor was cleaned by
distilled water and 70% isopropanol before use. At the
beginning, the fermentor was filled with 15 L of
medium and after 1- 2 hours 1.5 L of growing culture
(after 20 days of cultivation in three Fehrnbach flasks)
was added. Afterwards, every day 5 L of medium were
added into the fermentor until 35 L of medium were
reached. The cultures were illuminated continuously
with banks of cool white fluorescent tubes of
8gmol/m2 and incubated at temperature of 26°C to
28°C adjusted using a heater. The pH-value of the large
scale culture was adjusted to 7.4-8.5 using CO2
The biomass was collected by centrifugation at 6500 rpm
in a refrigerated continuous-flow centrifuge and
lyophilized, then stored at -20°C.
General purpose media for cyanobacteria (blue green algae) :
Allen and Arnon's Medium (modified):
This medium is generally used for nitrogen-fixing cyanobacteria. If
0.20 g of potassium nitrate is added, the medium supports the
growth of many non-nitrogen-fixing cyanobacteria.
A5 trace elements stock
1. Phosphate Storage:
• Polyphosphate bodies contain metals, mostly potassium,
calcium, and magnesium. Polyphosphate bodies in
heterocysts of Anabaena showed an increased content of S
and Mo and a reduction in the Ca content. The fact that
polyphosphate bodies can take up heavy metals led to the
hypothesis that polyphosphate bodies may be important in
• The enzyme involved in the synthesis of polyphosphates in
cyanobacteria is thought to be polyphosphate synthetase
(polyphosphate kinase), which catalyses the formation of
polyphosphate from ATP. No polyphosphate is required as a
primer but the enzyme requires magnesium.Polyphosphates
are broken down by alkaline polyphosphatase.
• Nitrogen can be stored in cyanobacteria in the
form of electron-dense granules, called structured
granules, containing cyanophycin granule
polypeptide (CGP) .
• CGP consists of a simple polypeptide, composed of
arginine and aspartic acid in a 1 : 1 molar ratio and
is called multi-L-arginil-poly(L-aspartic acid), or
• Cyanophycin is unique to cyanobacteria ,but is not
found in all species.
3. Phycobilin pigments:
• Phycobilisomes are composed of light-harvesting
phycobilin pigments that transfer absorbed light to
photosystem II reaction centres.
• Phycocyanin is sometimes regarded as a nitrogen
• It is rapidly degraded during N starvation and the
apoprotein synthesis is specifically repressed.
• However, kinetic analyses have shown that when N is
available, phycocyanin is always synthesised after the
formation of cyanophycin and when N is limiting,
phycocyanin is degraded after CGP.
The compartmentalization of the cyanobacterial cell:The thylakoid membrane,the internal
membrane system that separates the cytoplasm from the lumen and that is present in
virtually all cyanobacteria,contains both photosynthetic and respiratory electron transport
chains. These electron transport chains intersect,and in part utilize the same components in
the membrane. Note that oxygenic photosynthesis (conversion of CO2 and water to sugars
using the energy from light) essentially is the reverse of respiration (conversion of sugars to
CO2 and water releasing energy). The cytoplasmic membrane,separating the cytoplasm
from the periplasm,contains a respiratory electron transport chain but not photosynthetic
complexes in most cyanobacteria. Therefore,in most cyanobacteria,photosynthetic
electron transport occurs solely in thylakoids, whereas respiratory electron flow takes place in
both the thylakoid and cytoplasmic membrane systems.
(PS II) uses light energy to split water and to reduce the PQ pool. Electrons are
transported from the PQ pool to the cytochrome b6f complex and from there to a
soluble electron carrier on the luminal side of the thylakoid membrane. In
cyanobacteria this soluble carrier may be plastocyanin or cytochrome
c553,depending on the species and on the availability of copper (plastocyanin is a
copper containing enzyme). Either of these soluble one-electron carriers can reduce
the oxidized PS I reaction centre chlorophyll,P700 . This oxidized form of the reaction
centre chlorophyll is formed by a light-induced transfer of an electron from PS I to
ferredoxin (Fd) and eventually to NADP. Reduced NADP can be used for CO2 fixation.
Photosynthetic electron transfer leads to a proton gradient across the thylakoid
membrane. In PS II,protons are released into the lumen upon water splitting,and
protons formed upon plastoquinol oxidation by the cytochrome b6f complex are
released into the lumen as well. The proton gradient across the thylakoid membrane
is used for ATP synthesis by the ATP synthase in the thylakoid; this ATP may be
applied for CO2 fixation and for other cell processes.
REGULATION OF PHOTOSYNTHESIS
• If light is abundant,the photosynthetic electron
transport chain has a much higher capacity of
electron flow than has the respiratory chain,
• but at very low light intensity or in darkness
respiratory rates are higher than those of
Phycobilisomes which are attached to the Surface of the
Thylakoids . Phycobilisomes contain Accessory
Pigments for Photosynthesis . These are Water Soluble and
are stabilized by bonds to Proteins.
PS I activity is abundant relative to that
of the cytochrome b6f complex
Conditions affect on
A juicy, yummy microbial
mat, full of cyanobacterial
Nutrient Availability: Nutrients are a limiting factor for cyanobacteria populations. As long as the
correct nutrients are in excess, they can grow until some other factor, often light or temperature,
Competition: Ability to adapt to the environment is a big factors determining whether a bloom will
form. Many blue-greens are less edible, have gas vacuoles that help them float, can sequester
nutrients at the sediment water interface, or can fix dissolved nitrogen, any of which can give them
a competitive advantage over other algae and lead to bloom formation.
Light Intensity: Since cyanobacteria are phytoplankton, light is important and different species
thrive under different light intensities. If light is not extinguished by particles or color in the water, a
bloom is more likely. Many blue-greens thrive under low light, and so may be favored unless light is
nearly absent (such as in some high particulate reservoir systems).
Mixing: Mixing allows nutrients to be more evenly distributed and affects other aspects of water
quality that in turn affect algal abundance and composition. Mixing can also move algae to depths
with less light, limiting growth and survival. In general, blue-greens do better wtih less mixing
(Cylindrospermopsis is one taxon that seems to do well in mixed systems, though).
Temperature: Surface water temperatures consistently above 28 degrees Celsius (82 degrees
Fahrenheit) encourage blue-green blooms, although blooms may still occur in late fall (October,
November) in the Northern U.S.
Species: The above factors influence different species very differently, because each species or
taxon has a unique way of dealing with their environment. There are generalizations that apply to
blooms and blue-green dominance, but ther are exceptions in most cases. Algal bloom formation is
a complicated ecological process.
Toxicity: Not all blue-greens are toxic, so while risk may be higher during a bloom, high biomass
does not necessarily result in toxicity. Also, although many toxin producing algae produce taste and
odor compounds, the presence or absence of geosmin or MIB is not a predictor of the presence of
The pH and moisture of soil and
population of cyanobacteria in four
seasons of the year
Effects of cyanobacteria on plant and soil.
Analysis was performed with independent
Algalization in paddy field
(1) Increase in soil pores with having filamentous structure and
production of adhesive substances.
(2) Excretion of growth-promoting substances such as hormones
(auxin, gibberellin), vitamins, amino acids (Roger and Reynaud
1982, Rodriguez et al. 2006).
(3) Increase in water- holding capacity through their jelly structure
(Roger and Reynaud 1982).
(4) Increase in soil biomass after their death and decomposition.
(5) Decrease in soil salinity.
(6) Preventing weeds growth.
(7) Increase in soil phosphate by excretion of organic acids (Wilson
Effect of cyanobacterial biofertilizer
inoculation on rice grain yield at a
Mishra and Pabbi (2004)
the open-air algal biofertilizer production technology
for production at farmers’ level is not popular among the
The main limitations of this technology are:
•due to open air nature of production it can be produced for only a
limited period in a year (3-4 months in summer; Production has to be
stopped during rainy and winter season),
•high level of contamination due to open type of production,
•slow production rate,
• low population density and hence need for heavy inoculum per
1. The individual unit in the polyhouses can be of either
RCC, brick and mortar, or even polythene lined pits in the
ground. The algae are grown individually as species, by
inoculating separate tanks with laboratory grown pure
cultures, so as to ensure the presence of each required
strain in the final product.
2. Once fully grown, the culture is harvested, mixed with
the carrier material, presoaked overnight in water and
multani mitti (in 1:1 ratio) and sun dried. The dried
material is ground and packed in suitable size polythene
bags, sealed and stored for future use.
3. The final product contains 10,000 to 1,00,000 units or
propagules per gm of carrier material and, therefore,
500 g material is sufficient to inoculate one acre of rice
Mishra and Pabbi (2004)
Luxuriant growth of Cyanobacteria in a
Among the proposed
photobioreactor is one of the most
suitable types for outdoor mass
cultures. Most outdoor tubular
usually constructed with either glass
or plastic tube and their cultures are
re-circulated either with pump or
preferably with airlift system. They
can be in form of horizontal /
serpentine, vertical near horizontal,
conical, inclined photobioreactor.
Aeration and mixing of the cultures in
tubular photobioreactors are usually
done by air-pump or airlift systems.
Tubular photobioreactor are very suitable for outdoor
mass cultures of algae since they have large
illumination surface area. Tubular photobioreactors
consist of straight, coiled or looped transparent
tubing arranged in various ways for maximizing
tubular photobioreactors completely isolate the
culture from potentially contaminating external
environments, hence, allowing extended duration
photoinhibition is very common in outdoor tubular
photobioreactors .When a tubular photobioreactor is
scaled up by increasing the diameter of tubes,
the illumination surface to volume ratio would
decrease. On the other hand, the length of the tube
can be kept as short as possible while a tubular
photobioreactor is scaled up by increasing the
diameter of the tubes. In this case, the cells at the
lower part of the tube will not receive enough light
for cell growth (due to light shading effect) unless
there is a good mixing system.
Large illumination surface
area, suitable for outdoor
cultures, fairly good biomass
Gradients of pH, dissolved
oxygen and CO2 along the
tubes, fouling, some degree
of wall growth, requires large
Seaweeds are macrophytic algae, a primitive type of
plants lacking true roots, stems and leaves.
Most seaweeds belong to one of three divisions - the
Chlorophyta (green algae), the Phaeophyta (brown
algae) and the Rhodophyta (red algae).
There are about 900 species of green seaweed, 4000
red species and 1500 brown species found in nature.
The green seaweeds Enteromorpha, Ulva, Caulerpa and
Codium are utilized exclusively as source of food.
Khan and Satam (2003)
the Single Rope Floating Raft
(SRFR) technique developed by
CSMCRI is suitable for
culturing seaweeds in wide area
and greater depth.
A long polypropylene rope of 10
mm diameter is attached to 2
wooden stakes with 2 synthetic
fiber anchor cables and kept
afloat with synthetic floats.
The length of the cable is twice
the depth of the sea (3 to 4 m).
Each raft is kept afloat by
means of 25-30 floats. The
cultivation rope (1 m long x 6 m
diameter polypropylene) is
hung with the floating rope.
A stone is attached to the lower
end of the cultivation rope to
keep it in a vertical position.
Generally 10 fragments of
Gracilaria edulis are inserted
on each rope. The distance
between two rafts is kept at 2
Chinese people provide fertilizer to
Hungry fish and animals cause
damage to seaweeds