Chemical and Microbiological Examinations of Water and Fish Taken from Manzala Lake of Damietta Gavernorate, Egypt

Water and fish samples were collected in three replicates from the same site of Manzala lake water of El-Roda city in Damietta Governorate, Egypt were examined. Morphological examination of fish obtained from Manzala lake water was examined. The highest value of BOD5 20 was found during summer being 14.8 mgO2/L while the lowest value was found during winter being 7.6 mgO2/L. Arsines and Stannum did not present in all examined seasons of all samples (water and fish). Lead did not detected in all seasons samples except in spring being 0.003 and 0.003 ppm in water and fish, respectively. Also, cadmium and cupper did not presented in all fish samples. Lead did not detected in spring and summer samples while the highest value was during winter being 0.007 ppm in water and 0.032 ppm during autumn in fish. The highest value of total bacterial count in Manzala lake water was found during spring being 4400 cfu/ml ×10, while the lowest value was in autumn. The highest value of total fungal count was in summer being 22500 cfu/ml ×10 while lowest value was in the winter being 0.06 cfu/ml ×10. There were no bacterial growth on SS agar medium. The highest value of Staphylococci count was in spring being 1760 cfu/ml ×10. The highest value of Aeromonas count in spring being 66 cfu/ml×10. The highest value of coliform count was in spring being 1210 cfu/ml×10. The total bacterial count of fish muscles were 17.6, 6000, 0.06 and 45 cfu/g ×10 in spring, summer, autumn and winter, respectively. On the other hand, the highest value of total bacterial count of fish intestine was 46200 cfu/g ×10 in spring, but the lowest value was in the autumn. Total bacterial count of fish surface were 1980, 500, 0.2 and 10 cfu/g ×10 in spring, summer, autumn and winter, respectively. The highest values of fungal count in muscles, intestine and fish surface being 1.87, 13200 and 46.2 cfu/g ×10 during spring, respectively. The highest values of Staphylococcal counts of fish muscles, intestine and fish surface were in spring being 0.198, 33 and 77 cfu/g ×10. The highest count of Aeromonas sp. was in fish intestine during spring, being 2530 cfu/g ×10. Coliform was found in the highest values in spring being 1210000 cfu/g ×10 in intestine, and the lowest values in the autumn and winter. There was no correlation coefficient (r = 0.00) between the log of total bacterial count and BOD5 20 in the Manzala lake water. Among 19 bacterial isolates, only one was coccoid shape, 13 isolates were short rods and 5 isolates were long rods. Thirteen isolates were Gram negative and 6 isolates were Gram positive. Six isolates were spore formers and 13 isolates were non spore formers. All isolates gave negative results with acid fast stain. Micrococcus sp., Aeromonas sp., Esherichia sp., Pseudomonas sp., Aspergillus alliaceus, Aspergillus niger, Aspergillus flavus and Penicillium sp. were isolated and identified from water and fish.