Biology Reference
In-Depth Information
Table 3:
Comparative account of LPP-1 group of cyanopodoviruses.
Sr. No.
Property
LPP-1
LPP-1G
D-1
1
Morphology
Icosahedral head
with tail
Icosahedral head
with tail
Icosahedral head
with tail
2
Size of
Particle
Head 60 nm dia.
Tail 15 nm dia.
15-20 nm long
Head 50-60 nm dia.
Tail 28-37 nm long
Head 58.6 nm dia.
Tail 20 nm long
3
Nucleic acid
DNA
DNA
DNA
4
Plaque size
0.1-1.0 mm
Nt
Nt
5
Adsorption period
60 min.
60 min.
30 min.
6
Latent period
8 h
6-7 h
40 h
7
Temperature of
Inactivation
60 min at 55°C
Nt
Nt
8
Stability
Stable at 4°C for 3 h
Nt
Nt
9
Requirement of Mg
2+
Require Mg
2+
Nt
Nt
10
Serological
relationship
Neutralization with D-1
antiserum
Neutralization with LPP-1
antiserum; Neutralization
with D-1 antiserum not
tested
Neutralization with LPP-1
antiserum; Neutralization with
LPP-1G antiserum not tested
Nt: Not tested
dozen proteins have been identifi ed in the virion and the dsDNA has a G+C content of 66-67 mol%,
identical to host. The infection process of SM-1 has been described by Mackenzie and Haselkorn
(1972b).
Venkataraman
et al
. (1973) isolated a cyanophage that infects unicellular
A. nidulans
and the
colonial form
Chroococcus minor
from a waste stabilization pond inside IARI, New Delhi. This
cyanophage has a polyhedral head of 62.5 nm in diameter with a non-contractile tail of 25 nm (Sharma
and Venkataraman, 1977). AC-1 is considered close to SM-1 in its morphology. The differences
between SM-1, AC-1 and LPP-1 are given in Table 4.
Phage AN-22 described by Hu
et al.
(1981) is a cyanopodovirus with a edge-edge diameter of
the head of 54 nm and an exceedingly short tail. From freshwater and seawater bodies of Romania,
Moisa
et al
. (1981a) isolated 31 strains of cyanophages active against
Phormidium
sp. Of these, three
types of virus particles differing in tail length and with a morphology similar to that of T-odd
Table 4:
Comparative account of freshwater cyanopodoviruses.
Property
SM-1
AC-1
LPP-1
Shape and size of
particles
Polyhedron with no obvious tail;
88 nm dia.
Polyhedron with tail;
25 nm dia.
Polyhedron with tail;
15-20 nm
Stability
Stable in H
2
O
Stable in its lysate
Unstable; requires Mg
2+
ions
Adsorption
----
40 min.
60 min.
Latent period
30 h
30 h
8 h
Plaques
Less than 1-2 mm
4-6 mm after 10 days
Less than 1 mm
Temperature of
inactivation
60 min at 55°C
Nt
60 min at 55°C
Serological relationship
No neutralization with LPP-1, AS-1
antiserum
Nt
No neutralization with
SM-1 & AS-1 antiserum
Host range
S
.
elongatus
M
.
aeruginosa
A
.
nidulans
C
.
minor
Lyngbya
sp.,
Phormidium
sp.,
P
.
boryanum
Nt: Not tested
