摘要：Plants are rich in secondary metabolites and are being used for the treatment of various ailments in the indigenous system of medicine. Many developing countries are facing illnesses, and deaths among children are caused by germs, which get into the mouth via water and food. In addition, it has been estimated that up to 80% of all disease and sickness in the world is caused by inadequate sanitation, polluted water or unavailability of water. Thus, this study investigates the water purifying property of Moringa oleifera seed powder and determines the role of seed extracts against a few bacterial growths. Water samples were obtained randomly during January and February, 2015, from the Angereb and Shinta rivers, Gondar, Ethiopia. Both sites of water samples were subjected for purification studies and treated with dried seed powder. Treated water samples were subjected to bacteriological analysis using most probable number technique. Addition of aluminum sulfate as a coagulant lowered the water pH from 7.2 to 3.66, while the seed extract water pH remained the same. Treatment of 0.016 g/L of M. oleifera decreased water turbidity from 208.3 nephelometric turbidity units (NTU) to 33.66 NTU (83.84%) and from 129 NTU to 16.8 NTU (86.98%) for the Shinta and Angereb river water samples, respectively. The highest microbial load reduction was found with the Angereb (97.17%) and Shinta (97.50%) rivers. The acetone extracts showed maximum antibacterial activity with 19.00 mm against Salmonella typhii (clinical isolate), while Shigella dysenteriae (clinical isolate) was the least sensitive with 7.66 mm on the aqueous extract. The most frequent MIC value was 6.25 mg/mL followed by 12.5 mg/mL. The acetone extract is the most potent in inhibiting and killing the test organisms at a very low concentration for Shigella typhii. Taken together, the seed powder exhibits a remarkable reduction in turbidity and coliform count which makes the seed powder a good source for water purification. The acetone extract of seed had a strong antibacterial activity. It reveals that the seed powder and its extract can control and reduce waterborne bacterial diseases. This investigation facilitates benefits to those who cannot afford and or have access to clean drinking water in Ethiopia and elsewhere.
