International Journal of Aquaculture, 2018, Vol.8, No.4, 23-28
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Figure 1 Three study stations in Al-Qurna city
1.2 Heavy metals detection
Three elements, lead (Pb), Copper (Cu), Iron (Fe) were analyzed by atomic absorption in marine science center,
Basrah university. The concentration was determined by ppm.
1.3 Isolation and identification of bacteria
The isolated bacterial species were identified by the following the morphological and biochemical characteristics
of the individual colony was recorded. The individual colony was transferred to nutrient agar. The isolates were
subjected to following different biochemical test for example Gram staining, Motility test, Indole test, Methyl red
test, Voges Proskauer test, catalase test, Nitrate test and Carbohydrate fermentation test as described by (Jolt et al.,
1994).
The samples were inoculated in Brain heart infusion broth, incubated at 37°C for 24 h. The growing bacteria on
the medium were sub cultivated on MacConkey plates agar, Blood agar plates, nutrient agar, Mannitol salt agar
and Thiosulfate-citrate-bile saltssucrose agar (TSBS agar) and Eosin Methylene Blue agar (EMB agar), all plates
were incubated in condition at 37°C for 24 h. Microscopic examination such as motility test, morphology, and
staining reactions (Monica, 2006) were determined under the compound light microscope. Biochemical tests
included Indole test Methyl red (IMVIC) test, Voges-Proskaur test and Citrate utilization test, Triple sugar iron
test (TSI) and oxidase test were demonstrated.
2 Results and Discussion
2.1 Chemical analysis of heavy metals composition
Chemical analysis of heavy metals by atomic absorption for samples collected from three rivers located near
Al-Qurna city were shown in Table 1.
The heavy metal composition of the water samples from the three stations located near Al-Qurna city showed that
the highest level of iron, lead, zinc was observed in the water sample from sampling station 2 with values of 0.35,
0.02 and 1.29 mg/L, respectively. The highest copper concentration was observed in the water sample from
sampling station 3 (0.18 mg/L).
