This document discusses cyanophages, which are viruses that infect cyanobacteria. It begins by providing background on cyanobacteria, noting that they are aquatic photosynthetic bacteria that can form large blooms. It then introduces cyanophages, the first of which were discovered in 1963 infecting cyanobacteria. Cyanophages have heads and tails like other bacteriophages and use cyanobacteria as hosts in their lifecycles. They are classified based on morphology into families including Myoviridae, Podoviridae, and Siphoviridae. Genera within these families like Cyanomyovirus, Cyanopodovirus, and Cyanostylovirus are then described in terms of their morphological characteristics. The

1. SRI PARAMAKALYANI COLLEGE
( Reaccredited with B Grade with a CGPA of 2.71 in the II Cycle by NAAC
Affiliated to Manonmaniam Sundaranar University, Tirunelveli)
ALWARKURICHI 627 412 TAMIL NADU, INDIA
POST GRADUATE & RESEARCH CENTRE - DEPARTMENT OF MICROBIOLOGY
(Government Aided)
II SEM - CORE –VIROLOGY
UNIT – 3
OTHER VIRAL TYPES - CYANOPHAGE
G.S.AMRISH VARSHAN
REG NO: 20211232516102
I M.SC.MICROBIOLOGY
ASSIGNED ON:
TAKE ON :
Submitted to,
GUIDE: Dr.C.MARIAPPAN, Ph.D,
ASSISTANT PROFESSOR,
SRI PARAMAKALYANI COLLEGE,
ALWARKURICHI.

2. CYANOBACTERIA
• Cyanobacteria are microscopic, photosynthetic, aquatic bacteria.
• It is generally found in fresh water, lake, Oceans, Stream, Moist soil and rock
• Cyanobacteria is also called as blue green algea and also called as cyanopyte
• Cyanobacteria have internal membrane and flattened sacs called as thylakoids
• In thylakoids photosynthesis process is carried out
• Examples of cyanobacteria are Spirulina, Nostac, Anabena

3. • Cyanobateria are microscopic but its colony is large enough to cause large
blooms
• These blooms are harmful to plants, animals, human beings and aquatic
organisms
• these cyanobateria forms various colour of blooms in the suface the water
depending upon the pigments present
• These blooms causes depletion of oxygen present in the water
• This layer cause the depletion of oxygen in water and affects aquatic life
• It may also release some toxins in the water and affects the taste and odour
of water

4. • Cyanobateria are microscopic but its colony is large enough to cause large
blooms
• These blooms are harmful to plants, animals, human beings and aquatic
organisms
• these cyanobateria forms various colour of blooms in the suface the water
depending upon the pigments present
• These blooms causes depletion of oxygen present in the water
• This layer cause the depletion of oxygen in water and affects aquatic life
• It may also release some toxins in the water and affects the taste and odour
of water

5. CYANOPHAGE
• Cyanophage was first discovered by in 1963 by Safferman and Moriss they
discovered the first cyanophage
• Cyanophage is a virus that infects the cyanobacteria.
• Cyanophage use cyanobacteria for its replication and multiplication its use
cyanobacteria as a host for its life cycle.
• These cyanophages may be found in both fresh water and marine
enviroinment

6. • These marine and fresh water cyanophages have icasohedral head which conatain a
double stranded DNA connects to a tail by a connector protein
• These cyanophages are classified within the bacteriophage family Myoviridae (e.g. AS-1, N-
1), Podoviridae (e.g. LPP-1) and Siphoviridae (e.g. S-1).
MORPHOLOGY
• Like other bacteriophage cyanophage have a capisd and a tail , the capsid conatin the
genetic material
• DNA is approximately 45 kbp long The tail binds the virus to the host cell and
transfers viral DNA to the host cell upon infection. Based on morphological
characteristics, cyanophages are placed into the families Myoviridae, Podoviridaeand
Siphoviridae,

7. Cyanomyovirus
• The type species for Cyanomyovirus of the family Myoviridae is Cyanophage
AS-1, which was isolated from a waste stabilization pond, and was also the
first genus recognized.
• The tails have been observed as either contractile or non contractile with
lengths of 20 to 244 nm, widths of 15 to 23 nm, and a shrinking range of
93 nm.
• Cyanophages generally have isometric hexagonal heads with diameters
ranging from 55 to 90 nm. There is large morphological variation in this
group, which suggests that they infect a variety of host species.At the point
of attachment between the long tail and the head there is a base plate where
short pins are attached, a contractile sheath, and an internal core, similar to
other bacteriophages in the Myoviridae.

8. Cyanopodovirus
• Cyanopodovirus, within the Podoviridae, are present in both fresh and marine
water.
• The type specimen of cyanopodovirus is Cyanophage LPP-1, which
infects Lyngbya, Plectonema and Phormidium.
• Their capsids are polyhedrons that appear hexagonal in 2-D and the tails are
hollow with sixfold radial symmetry made of rings of six subunits with
unknown orientation.Similar to cyanomyoviruses, they can be found in
waste-stabilization ponds and have isometric capsids of similar size but
shorter tails.

9. Cyanostylovirus
• Cyanostylovirus belong to the family Siphoviridae, where the type species is
Cyanophage S-1, which is known to infect Synechococcus.
• Cyanostyloviridae have smaller (50 nm in diameter) isometric capsids than
the previous genera but longer tails (140 nm).
• Other genera in this family have tails that range from 200 to 300 nm in
length.

10. Host
• The host range of cyanophages is very complex and is thought to play an
important role in controlling cyanobacterial populations.
• Freshwater cyanophages have been reported to infect hosts in more than
one genus although this may also reflect problems in the taxonomic
classification of their hosts.
• Nonetheless, they have been classified into three major groups based on
the taxonomy of their host organism.

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