2. ⚫Introduction to Cyanophyceae:
⚫It is a primitive group of algae, consists of 150
genera and about 2,500 species. In India, the
division is represented by 98 genera and about 833
species. Members of the class Myxophyceae
(Cyanophyceae) are commonly known as blue
green algae. The name blue green algae is given
because of the presence of a dominant pigment c-
phycocyanin, the blue green pigment.
⚫In addition, other pigments like chlorophyll a (green),
c-phycoerythrin (red), β-carotene and different
xanthophylls are also present. The members of this
class are the simplest living autotrophic prokaryotes.
3.
4. ⚫ Important Characteristics of Cyanophyceae:
⚫ 1. The individual cells are prokaryotic in nature. The
nucleus is incipient type and they lack membrane bound
organelles.
⚫ 2. Both vegetative and reproductive cells are non-
flagellate.
⚫ 3. Cell wall is made up of microfibrils and is
differentiated into four (4) layers. The cell wall composed
of mucopeptide, along with carbohydrates, amino acids
and fatty acids.
⚫ 4. Locomotion is generally absent, but when occurs, it is
of gliding or jerky type.
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5. ⚫ 5. The principal pigments are chlorophylls a (green), c-
phycocyanin (blue) and c-phyco- erythrin (red). In
addition, other pigments like β-carotene and different
xanthophylls like myxoxanthin and myxoxanthophyll are
also present.
⚫ 6. Membrane bound chromatophore are absent.
Pigments are found embedded in thylakoids.
⚫ 7. The reserve foods are cyanophycean starch and
cyanophycean granules (protein).
6. ⚫ 8. Many filamentous members possess specialized cells
of disputed function (supposed to be the centre of
N2 fixation) known as heterocysts.
⚫ 9. Reproduction takes place by vegetative and asexual
methods. Vegetative reproduction takes place by cell
division, fragmentation etc. Asexual reproduction takes
place by endospores, exospores, akinetes, nannospores
etc.
⚫ 10. Sexual reproduction is completely absent. Genetic
recombination is reported in 2 cases.
7. ⚫ Thallus Organisation in Cyanophyceae:
⚫ Plants of this group show much variation in their thallus
organisation.
⚫ The thallus may be of unicellular or colonial forms:
⚫ 1. Unicellular Form: In unicellular form, the cells may be
oval or spherical. Common members are Gloeocapsa (Fig.
3.23A), Chroococcus and Synechococcus.
⚫ 2. Colonial Form: In most of the members the cells after
division remain attached by their cell wall or remain together
in a common gelatinous matrix, called a colony.
⚫ The colonies may be of two types: a. Non- filamentous,
and b. Filamentous
13. ⚫ a. Non-Filamentous Type: The cells of this type divide
either alternately or in three planes, thereby they form
spherical (Gomphosphaera, Coelosphaerum), cubical
(Eucapsis alpine, Fig. 3.23C), squarish (Merismopedia) or
irregular (Microcystis, Fig. 3.23B) colony.
⚫ b. Filamentous Type: By the repeated cell division in one
plane, single row of cells are formed, known as trichome.
e.g., Oscillatoria (Fig. 3.23D), Spirulina, Arthosporia etc.
The trichome when covered by mucilaginous sheath is
called a filament. The filament may contain single
trichome (Oscillatoria, Lyngbya) or several trichomes
(Hydrocoleus, Microcoleus, Fig. 3.23E).
⚫ The trichomes may be unbranched (Oscillatoria,
Lyngbya), branched (Mastigocladus limilosus, Fig. 3.23J)
and falsely branched (Scytonema, Fig. 3.23K and
Tolypothrix).
14. ⚫ Reproduction in Cyanophyceae:
⚫ The blue green algae (Cyanophyceae) reproduce by both
vegetative and asexual means. Sexual reproduction is
absent.
⚫ The vegetative reproduction performs through fission
(Synechococcus), fragmentation (Oscillatoria,
Cylindrospermum muscicola), hormogonia formation
(Oscillatoria, Nostoc), hormospores (Westiella lanosa),
planococci and Palmelloid stage.
⚫ During asexual reproduction various types of asexual
spores are formed. These are akinetes (Anabaena
sphaerica, Gloeotrichia natans, Calothrix fusca),
endospores (Dermocarpa), exospores (Chamaesiphon)
and nannocyte (Microcystis) (Fig. 3.27).
15.
16. •
•
• 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
indeserts.
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 blue-
green paint or scum.
Habitat
17. Production
• 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.
18. 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
fluorescence lamps.
•The stock cultures were
maintained for 20-30 days.
19. 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
weeks.
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
solvent.
20. The large scale cultivation was carried out in a 45 liter-
glass 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
supplementation.
The biomass was collected by centrifugation at 6500 rpm in a
refrigerated continuous-flow centrifuge and lyophilized, then
stored at -20°C.
21. Composition :
Magnesium Sulphate
(MgSO4 .7H2O)
0.025 g
Calcium chloride 0.05 g
Sodium chloride 0.20 g
Dipotassium hydrogen
phosphate
0.35 g
A5 trace elements stock
solution
1.0 ml
Glass-distilled water 1,000 ml
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.
23. Akinetes are asexual propagules which
derived from the vegetative cells. It
protects in unfavourable condition this
aids in asexual reproduction
24. 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,
becomes limiting.
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
toxins.
25. The pH and moisture of soil and
population of cyanobacteria in
four seasons of the year
26. Effects of cyanobacteria on plant and
soil. Analysis was performed with
independent Samples t-test
27. 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
2006)
29. Mishra and Pabbi (2004)
Effect of cyanobacterial
biofertilizer inoculation on rice
grain yield at a farmer’s field
30. for production at farmers’ level is not popular among
the
farming community.
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
hectare.
31. 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
growing area.
Mishra and Pabbi (2004)
34. Among the proposed
photobioreactors, tubular
photobioreactor is one of the most
suitable types for outdoor mass
cultures. Most outdoor tubular
photobioreactors are
usually constructed with either
glass or plastic tube and their
cultures are re-circulated either with
pump or preferably with airlift
system. Theycan be in form of
horizontal / serpentine, vertical near
horizontal, conical, inclined
photobioreactor.
Aeration and mixing of the cultures in
tubular photobioreactors are usually
35. Tubular photobioreactor are very suitable for outdoor
mass cultures of algae since they have large
illumination surface area. Tubular photobioreactors
consist of straight, or looped
arranged in
coiled
various ways for
transparent
maximizing
designed
capture.
photobioreactors
Properly
completely isolate the
tubing
sunlight
tubular
culture from potentially contaminating external
duration
environments, hence, allowing extended
monoalgal culture.
photoinhibition is very common in outdoor tubular
photobioreactors .When a tubular photobioreactor is
scaled up by increasing the diameter of
the illumination surface to volume ratio
tubes,
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.
