Biology Reference
In-Depth Information
Figure 3:
Filaments of
Nodularia spumigena
from Scandinavian Culture Collection for Algae and Protozoa (SCCAP
K-1353). Picture courtesy Gert Hansen,
S
candinavian
C
ulture
C
ollection of
A
lgae &
P
rotozoa, Department of Biology,
University of Copenhagen, Oester Farimagsgade 2D, DK-1353, Copenhagen, Denmark (http://www.sccap.dk/).
Thiel (1987) reported the presence of L-leucine and aminoisobutyric acid at Xaa and Zaa positions
in a strain of
M
.
aeruginosa
. Watanabe
et al
. (1988) compared the MC content of different strains of
Microcystis
(belonging to
M
.
aeruginosa
,
M
.
viridis
and
M
.
wesenbergii
). One strain of
M
.
aeruginosa
showed high amounts of MC-YR and a lesser amount of MC-LR. However, three toxins, i.e. MC-
RR, MC-YR and MC-LR were detected in two other strains of
M
.
aeruginosa
and four of M.
viridis
.
The main component of toxin in these species was MC-RR while
M
.
wesenbergii
did not show the
presence of any of the three MCs observed in the rest of the two species. Another variant, MC-LY with
L-leucine and L-tyrosine at Xaa and Zaa positions has been reported from a strain of
M
.
aeruginosa
(Stoner
et al
., 1989). MC-HtyR is a rare variant of MC produced by
A
.
fl os-aquae
,
M
.
aeruginosa
,
M
.
aeruginosa
UTEX and
M
.
viridi
s
with homo-tyrosine and arginine at Xaa and Zaa positions
(Botes
et al
., 1985; Watanabe
et al
., 1988; Harada
et al
., 1991a; Oh
et al
., 2000). Another such variant
containing 1,2,3,4-tetrahydrotyrosine and arginine, designated as MC-(H
4
)YR, from
Microcystis
spp.
was isolated by Harada
et al
. (1991a). MC-RR has also been recorded from
A
.
fl os
-
aquae
,
Anabaena
sp. strain 90, and
Anabaena
sp. strain 141 (Sivonen
et al
., 1992a). Bloom samples of
Microcystis
spp.
produced MC-AR, MC-FR (phenylalanine and arginine), MC-M(O)R and MC-WR (1-tryptophan
and arginine) (Namikoshi
et al
., 1992a). L-Glutamate and its δ-methylester [E(Ome)] are reported
to exist at Xaa and Zaa positions in MC-L-Glu[E(Ome)] in the MC produced by
Anabaena
sp. strain
186 (Namikoshi
et al
., 1998). Seven new MCs containing dehydroalanine (Dha) or L-serine (L-Ser)
instead of N-methyldehydroalanine unit and the L-Glu and/its δ-methyl ester [E (Ome) in place
of the two variable L-amino acids at Xaa and Zaa positions have been isolated from
Anabaena
sp.
strain 186 (Namikoshi
et al
., 1998).
M
.
aeruginosa
UTEX B 2666 produced MC-LF (with leucine and
phenylalanine at Xaa and Zaa positions) besides MC-LA, MC-LAba and MC-LR (Diehnelt
et al
.,
2006). Other MCs such as MC-VF, MC-HilR, MC-LL, MC-LF and MC-LW respectively contain valine,
phenylalanine; homoisoleucine, arginine; leucine, leucine; leucine, phenylalanine and leucine,
1-tryptophan at Xaa and Zaa positions. These have been described from cultures of
M
.
aeruginosa
