Isolation and Identification of Five Lead Bio-Remediating Bacterial Strains

The present investigation was implemented to search for high efficient bacterial strains in bio-remediating the toxic influence of Lead chloride (Pb Cl2) on faba bean plants grown in sandy soil supplemented with various concentrations of Pb Cl2. Five strains were isolated from Al-Taif, Al-Baha and Al-Madinah Al-Munawrah governorates from the rhizosphere of cucumber, fig and tomato plants respectively, KSA. Regarding efficiency of these isolated strains in remediating PbCl2 in the nutrient broth medium, the absorbed quantities ranged from 189 to 417 mg/l while the whole amount recorded in control was 612 mg/l. The isolated bacterial strains were genetically identified as Bacillus amyloliquefaciens subsp. plantarum Trigo Core 1448, Bacillus amyloliquefaciens subsp. plantarum UCMB 5033, Bacillus subtilis strain CCM 1999, Serratia marcescens strain WW4 and Bacillus amyloliquefaciens CC178. Bacillus amyloliquefaciens subsp. plantarum UCMB 5033 revealed the highest efficiency in absorbing Pb that reached 417 mg/l against 612 mg/l for the controls. Bioremediation of Pb-polluted soil with Bacillus amyloliquefaciens significantly increased faba bean plant height, plant fresh weight, dry weight, plant N, P and K concentrations compared to the non-inoculated treatments.