TY - SER AU - Diab,Atef M. AU - Shafik,Hisham M. AU - Abdelrafee,Sarah M. TI - Selective coagulation mechanism of Moringa Oleifera seeds on gram positive and gram negative bacteria KW - Moringa oleifera KW - Seeds KW - Gram-negative bacteria KW - Gram-positive bacteria N1 - Includes references N2 - It may be more practical and reliable to use coagulants such as Moringa oleifera (M. oleifera) instead of chemicals such as alum in rural areas where the economic situation, small population densities and affordability are key elements in achieving drinking water quality. This study focused on the coagulation power of M. oleifera seed powder water extract concentrations (v/v) (0.5%, 1% and 2%) at different time intervals (1, 2 and 3hrs). The efficacy of coagulation expressed in total viable bacteria (TVB) and total coliform (TC) counts increased with all concentrations as well as contact time, using Cellulose Nitrate Filter, 47mm diameter and pore size 0.45?m. Total microorganisms in the filtrate were enumerated using Nutrient agar and MacConkey agar culture media. Salmonella & Shigella and Vibrios were also enumerated using the same technique on Salmonella & Shigella agar (S&S) and thiosulfate-citrate-bile salts-sucrose agar (TCBS) culture media. There is dramatically decrease in all types and groups of bacteria after treatment with M. oleifera seed powder. After 1hr and 0.5% M. oleifera extract, counts of TVB, TC, S&S and Vibrios decreased by 95.5%, 98.4%, 98.9% and 85.3%, respectively. At 1% the decrease were 96.6%, 98.1%, 97.9% and 98.4%, respectively and at 2% the decreases were 97.3%, 98.2%, 98.4% and 85.5%, respectively. This will directly lead to risky bacterial population imbalance resulting in relatively high incidence of Gram-negative bacteria (usually pathogenic) compared with Gram-positive bacteria UR - http://nile.enal.sci.eg/EALE/2020/EJM/5520/1/27.pdf ER -