Page 21 - Volume 3, Issue 1, January 2010
Basic HTML Version
© Benaki Phytopathological Institute
Charistou
et al
.
20
scopic examination of all animals during the
necropsy at the end of the observation peri-
od did not reveal any abnormality. No effect
was noted on the negative control group of
5 female Wistar rats either (Group B).
It can be, therefore, concluded that the
tested OMW, produced in a three-phase ol-
ive mill in Rouva (Crete, Greece), is of low
acute oral toxicity to the test animals.
Acute Toxicity on the bacterium Vibrio
fischeri (Microtox® assay)
In a preliminary test, the acute toxici-
ty of the untreated OMW was tested on the
photobacterium
V. fischeri
following 5, 15
and 30 min of exposure and the determined
EC
50
values for the 15 and 30 min exposure
did not significantly differ. Therefore, in the
tests, in order to follow the acute toxicity of
the untreated and treated OMW on the pho-
tobacterium
V. fischeri,
the EC
50
values were
determined only after 5 and 15 min of expo-
sure.
Considering the EC
50
values (Table 2) de-
termined for the OMW sample and its fil-
trates (1), significant reduction in the toxic-
ity to
V. fischeri
after the 1
st
and 2
nd
cycle of
treatment was observed. More specifically,
the EC
50
values determined for the untreat-
ed OMW, the treated OMW after 1 cycle and
2 cycles of treatment were 0.219, 1.612 and
4.606% v/v, respectively. In addition, the
differences between the EC
50
values deter-
mined for the 5 min exposure were almost
the same with those after 15 min of expo-
sure.
The determined EC
50
values
for poly-
phenolic mixtures isolated from the tested
OMW, after passing through column XAD-4
or XAD-7HP on the photobacterium
V. fisch-
eri,
were 37.795 and 50.970 mg/l, respective-
ly, following 5 min of exposure. Compari-
sons of the EC
50
values obtained at 5 and
15 min of exposure (Table 3) demonstrat-
ed that the toxicity of the tested samples on
the photobacterium was almost completed
Table 1
. Acute oral toxicity of Olive Mill
Wastewater (OMW) on female Wistar rats,
expressed as body weight data.
Code
no.
Body weight (g)
Before oral
administration
7 days post
administration
14 days post
administration
G
ROUP
Α
Α-01 180
180
179
Α-02 162
168.5
170
Α-03 193
191.5
195
Α-04 165
170
174
Α-05 167
175
175
G
ROUP
Β
Β-01 175
178
182
Β-02 188
192.5
193
Β-03 180
185
186
Β-04 176
167
172
Β-05 172
180
184
Table 2.
Acute toxicity of untreated and treated Olive Mill Wastewater (OMW) on the bacteri-
um
Vibrio fischeri
(Microtox® assay), expressed as median effective concentrations (EC
50
).
Duration of
exposure
(min)
Untreated OMW
Treated OMW (1 cycle)
Treated OMW (2 cycles)
EC
50
(% v/v) (± SD
1
)
R
2
EC
50
(% v/v) (± SD)
R
2
EC
50
(% v/v) (± SD)
R
2
5
0.219 (±0.044)
0.945 1.612 (±0.687)
0.958
4.606 (±1.51)
0.976
15
0.187 (±0.035)
0.931 1.361 (±0.528)
0.944
4.374 (±1.54)
0.967
1
standard deviation
Table 3
. Acute toxicity of the polyphenolic
mixtures recovered from Olive Mill Waste-
water (OMW) on the photobacterium
Vibrio
fischeri
(Microtox®), expressed as median ef-
fective concentrations (EC
50
).
Duration of
exposure (min)
Polyphenolic
mixture
XAD-4
Polyphenolic
mixture
XAD-7HP
EC
50
(% v/v)
(± SD
1
)
R
2
EC
50
(% v/v)
(± SD)
R
2
5
37.795
(± 3.656)
0.978
50.98
(± 3.352)
0.987
15
37.995
(± 1.407)
0.938
52.42
(± 3.224)
0.977
1
standard deviation
