International Journal of Aquaculture, 2017, Vol.7, No.18, 122-127
123
possible use of
A. muricata
as potential antimicrobial in the farming of
C. gariepinus
.
2 Results
2.1 Determination of phytochemical in soursop leaves
Phytochemical screening of soursop leaves showed the presence of tannins, flavonoids, glucosinolates, phenol,
amino acid and polysterols while saponins was not detected. The metabolites were in moderate quality (++) and
small quality (+) as shown in Table 1.
Table 1 Determination of some important phytochemical of soursop leaves
Parameters
Soursop leaves
Saponins
-
Tannins
+
Flavonoids
+
Glucosinolates
+
Phenol
+
Proteins
++
Polysterols
+
Note: ++ = Moderate quantity; + = Small quantity; - = Absent
2.2 Microbial load of
Clarias gariepinus
The microbial load of fish tissues (skin, live, intestine and gills) were determined and the results showed that
highest enterobacteriacea and total viable counts were recorded in gills and the least in liver while no
enterobacteriacea and total viable counts were recorded in the control as shown in Table 2.
Table 2 Microbial load of
C. gariepinus
(liver, skin, intestine and gills)
Organ
Organism
Microbial load (log
10
CFU/g)
Control
Enterobacteriacea counts
-
Total viable counts
-
Liver
Enterobacteriacea counts
1.60 ± 0.01
Total viable counts
2.10 ± 0.02
Skin
Enterobacteriacea counts
2.15 ± 0.02
Total viable counts
2.54 ± 0.01
Intestine
Enterobacteriacea counts
2.12 ± 0.02
Total viable counts
2.36 ± 0.03
Gills
Enterobacteriacea counts
2.25 ± 0.04
Total viable counts
2.43 ± 0.06
2.3 Detection of antimicrobial activities of soursop leaves
Aqueous, methanolic and ethanolic extracts of soursop leaves shows antibacterial and antifungal properties in the
study against all tested pathogens with methanolic extracts had higher inhibition zone of diameter compared to
ethanolic and aqueous extracts while no antimicrobial activity were recorded in the negative control (distilled
water). But the positive control (chloramphenicol) at 10 mg/ml and 20 mg/ml recorded varies inhibition of zone of
diameters among the pathogens tested except
A. hydrophila
that did not show diameter of zone of inhibition in
aqueous, ethanolic and methanolic extracts of soursop leaves (Table 3).
2.4 Determination of minimum inhibitory concentration (mic) of aqueous, ethanolic and methanolic
extracts of soursop leaves
The MIC of aqueous, ethanolic and methanolic extracts of soursop leaves against four pathogenic bacteria isolated
from
C. gariepinus
and
O. niloticus
were assessed and the results revealed that 500 µg/ml prevented growth
against the pathogens tested except
A. hydrophila
and
S. iniae
that had 1000 µg/ml respectively (Table 4).
