Thesis (M.Sc.) - Cairo University - Faculty of Agriculture - Department of Microbiology

Water is the most important resource for humans. Approximately 75% of the earth{u2019}s surface is covered by water, but only 1% of that is drinkable. Twelve bottled water brands {9 domestic (A1, B2, A3, D4, H5, M6, N7, S8 and S9) and 3 imported (E10, H11 and Y12} were collected. Total bacterial count at 22oC and 35oC for all the tested brands of bottled water are laying under the limits of the Egyptian law. The tested brands of bottled water were almost free from indicator bacteria (coliform and fecal coliform) and some other pathogenic bacteria. Unfortunately two brands (D4 and M6) were found to be contaminated with Pseudomonas aeruginosea, with counts of 285 and 400 CFU/ 100 ml respectively. Protozoa detected in five tested bottled water brands B2, A3, D4, N7 and S8. All samples were under the recommendable limits for physical characteristics, where the pH values ranged from 7.2 to 7.92 and the TDS values ranged from 137 to 485 mg /l. The samples showed that local brands containing bacteria at the start time and slight elevation in total count of bacteria after 3 and 6 months, but the counts start to decline again at the 9th month and continued to decrease at the end of the year while the foreign brands are free of bacteria during the study. The unsuitable storing conditions (Sunny high from temperature ) has a great threat on the bacterial counts recorded in the selected bottled water brands as it is highly increased during the study period

Issued also as CD