International Journal of Marine Science, 2017, Vol.7, No.14, 125-129
127
Figure 2 Agar well diffusion method against
V. harveyi
,
S. aureus
and
E.coli
Figure 3 Antibacterial activity of crude extracts of
Cellana radiata
against three different pathogens
Table 1 Antibacterial activity against three different Pathogenic Bacteria
Pathogens
Methanol (mm)
Ethyl Acetate (mm)
Dry
Wet
Dry
Wet
Escherichia coli
Nil
Nil
Nil
Nil
Staphylococcus aureus
Nil
Nil
Nil
Nil
Vibrio harveyi
Nil
12
13
18
3 Discussion
From ancient times the molluscs are useful organisms which support the coastal communities as food and also
economically. These are used in medical applications and as bio-indicators in recent trends (Asta, 2011). The
molluscs, particularly gastropods were showing antibacterial properties. In the present study three different
pathogenic bacteria
viz
.
Escherichia coli
(human),
Staphylococcus aureus
(Fish) and
Vibrio harveyi
(Shrimp) were
tested to know the antibacterial activity against them to methanolic and ethyl acetate crude extracts. The wet
extract of methanol has shown antibacterial activity (12 mm) against
V. harveyi
. The ethyl acetate extracts by both
dry and wet methods have shown antibacterial activity against
V. harveyi
, the dry extract 13 mm and wet extract
18 mm.
V. harveyi
showing severe effect on commercially important resources like fish, shrimp and also pearl oysters and
causes mass mortality. The pearl oyster
Pinctada maxima
died and damaged heavily by
V. harveyi
infection
(Lester, 1989). Some gastropods have shown antibacterial activity against
V. harveyi
and in near future these
metabolites may be helpful to aquaculture industries. The
Donax faba
shell extract has shown inhibitory zone of 3
mm to
V. harveyi
from ethanol extract (Giftson and Patterson, 2014). The extracts of crude peptides shown zone of
inhibition to
V. harveyi
from pelecypods,
Crassostrea madrasensis
,
Saccostrea cucullata
,
Meretrix meretrix
,
Perna
viridis
,
Polymesodaerosa
and from gastropods,
Ficus gracilis, Hemifusus tuba, Bursa rana, Xenophora
mekranensis
and from cephalopods,
Sepeilla inermis
,
Octopus dolfusii
,
Vampyroteuthis infernalis
,
Loligosp
,
0
5
10
15
20
Dry
Wet
Dry
Wet
Methanol (mm)
Ethyl Acetate (mm)
Inhibitory zone (mm)
E.coli
Stphylococcus aureus
Vibrio harveyi
