Heavy metals biosorption by some bacterial species from drinking water

Abstract

The nine most frequent bacterial strains out of 127 were isolated from ten drinking water sa mples collected from tap wa ter and bottled water in Sharqia governorate. The nine isolates were purified and examined for their resistance to increasing concentrations of two heavy metal ions, namely lead (Pb+2) and iron (Fe+3). Pour strains out of the nine isolates encoded I, II, IV, and VIII showed the highest efficiency of both Pb+2 and Fe+3 uptake from nutr ient broth media containing 100 ppm of the heavy metal ions. The four bacteria were preliminary identified and the confirmed by th e B i olog exa min at ion as Corynebacteriumjeikeium, Pseudomonas putida biotype A, Acinetobacter calcoaceticus and Acidovorax delafeldii. The increased concentrations of Pb+2 ions (from 100 to 500) in

nutrient broth m edia h ad deleterious effect on the process of he vy metal uptake (biosorption) by a ll the four selected isolates. Where as percentage of Pb+2 uptake decreased from 42.9 to 24%; from 72.6 to 42%; from 78.9 to 37% and from 68.8 to 45%, for the four selected isolates, respectively.

Meanwhil e there was no significant change in Fe+3 uptakes percentage accompanying th e increase in heavy meta l ion con centrat ion.