ECO-DIVERSITY OF AQUATIC BACTERIA AND VIRUSES ISOLATED FROM RIVER NILE AND DRAINAGE WATER IN EGYPT

Abstract

River Nile as a main source of drinking water in Egypt‟ ‟ has become a matter of interest and one of the most important national goals. Rosetta branch has a great importance since it is one of River Nile branches and the main source of water in the Delta region. Unfortunately, it receives a variety of wastes coming from sewage, agricultural and industrial drainage that affect its water quality. From this point, the present study aims to study the biodiversity of bacteria and viruses resulting from some physical, chemical and biological factors to know the differentiation between the autochthonous and allochthonous microorganisms. On the light of the previously mentioned objective, water samples were collected in July 2010. These samples were subjected to physicochemical and microbiological analysis. The results of the study can be summarized as follows: Ecodiversity of water Physical factors 1- Temperature values ranged from (30°C-33°C) with note the absence of any source of thermal pollution. 2- pH values for all collected water samples are within the permissible limits of law 48/1982 (7.0–8.5). 3- Turbidity values ranged from in 6.08-37.5 and 8.6–86 NTU in both of Rosetta branch and drainage water, respectively. Chemical factors 1- EC values for water samples collected from drains outfalls were recorded elevated, where they fluctuated between (632-1484 μmhos/cm) in drains outfalls and from (333-582 μmhos/cm) in Rosetta branch, respectively. 2- TDS concentrations for water samples collected from Rosetta branch are within the permissible limits of law 48/1982 (˂ 500 mg/l) except for Rosetta branch, upstream El-Tahreer drain recorded 530 mg/l. On contrast, TDS concentrations for water samples collected from drains outfalls exceeded the permissible limits where they ranged from (523-950 mg/l) except for Zawiet El-Bahr drain outlet was recorded 405 mg/l and within the permissible limits. SUMMARY Mohamed I. Azzam, Ph.D., 2015 168 3- Ammonia concentrations for water samples collected from Rosetta branch and drains outfalls exceeded the permissible limits of the law 48/1982 (˂ 0.5 mg/l), where it ranged from (1.3664-7.517 mg/l in Rosetta branch) and (1.888-22.54mg/l in drains outfalls). Except for Rosetta branch, upstream El-Rahawy drain was recorded (0.324mg/l) and within the permissible limits. 4- DO values for water samples collected from Rosetta branch were variable compared to the permissible limits of law 48/1982 (>5 mg/l) where they fluctuated between (2.13-7.3 mg/l). On the other hand, DO values for water samples collected from drains outfalls violated that limit where they ranged from (0.18-4.12mg/l). 5- BOD concentrations for water samples collected from Rosetta branch were higher than the permissible limits in the law 48/1982 (˂ 6 mg/l) and ranged between (2-50mg/l). On the other hand, BOD concentrations for water samples collected from drains outfalls were high and exceeded the permissible limits in the law 48/1982 (˂ 10 mg/l) and ranged between (2-110mg/l) particularly for El-Rahawy and Sabal drains. Except for El-Tahreer and Zawiet El-Bahr drains outlet were recorded (2 & 8mg/l, respectively) and within the permissible limits. 6- COD concentrations for water samples collected from Rosetta branch were higher than the permissible limits in the law 48/1982 (˂ 10 mg/l) and ranged between (19-70mg/l). On the other hand, BOD concentrations for water samples collected from drains outfalls were high and exceeded the permissible limits in the law 48/1982 (˂ 15 mg/l) and ranged between (16-214mg/l) particularly for El-Rahawy and Sabal drains. 7- All Concentrations of nitrate (NO3 -) and phosphate (PO4 -3) were within the permissible limits in the Law 48/1982. The quantitative biodiversity for microorganisms 1- Standard plate count (SPC) bacteria at 22°C and 37°C in all collected water samples recorded high values and varied regionally. The highest value was recorded at El-Rahawy drain outlet. 2- Bacterial indicators (total coliform, fecal coliform and fecal streptococci) in all collected water samples exceeded the international permissible limits. 3- Salmonella sp. strains were isolated from only drains outlets. SUMMARY Mohamed I. Azzam, Ph.D., 2015 169 The qualitative biodiversity for microorganisms The water quality index (WQI) The water quality index (WQI) revealed that, El-Rahawy and Sabal drains have a very bad water quality, while its upstream El-Rahawy drain water was medium. The other studied drains as well as the rest of selected points in Rosetta branch were evaluated as being of bad quality and suffer mainly from bacteriological pollution. Isolation and identification of bacteria found in water samples Identification of bacteria involved isolation of “225” isolates, out of which “212” isolates were identified into “7” different species belonging to “3” main bacterial groups. These species were: Citrobacter freundii, Enterococcus faecalis, Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa, Salmonella sp., & Staphylococcus aureus.