Efficacy of Moringa oleifera seed extract on the microflora of surface and underground water

Abstract

The efficacy of Moringa oleifera seed (LAM) in reducing total bacteria and coliforms in raw water was studied. Its antibacterial activity on some selected enteric bacterial pathogens was also investigated. About 88 and 97.5% of the total bacteria and coliforms,, respectively were reduced in the surface water after 24 h of treatment. Meanwhile, in the underground water sample, the seed extract reduced the total bacteria and coliforms by 88.3 and 93.3% with a precipitation rate of 7.7×102 and 2.42×102 cfu h-1, respectively. The coagulating efficiency and zones of inhibition increased correspondingly with an increase in concentration of the seed extract. At a concentration of 30 μg mL-1, there was no microbial growth recorded in the water samples even after 96 h storage. However when Escherichia coli, Salmonella typhi and Shigella dysenteriae were exposed to the seed extract, a secondary bacterial growth resulting into an increase of about 185, 189 and 198% in their concentrations, respectively was observed after 24 h. The minimum inhibitory concentration of the seed extract ranged between 20 and 50 μg mL-1. © 2007 Academic Journals Inc.