Activation of Lead (Pb) in Soil by Bacteria

Adding a certain concentration of Pb
²⁺
to the culture medium. Two strong lead-resistant strains of microorganisms labeled as J13 and Y7, were selected from six soil samples, J13 and Y7 belongs to Erwinia sp. and Bacillus respectively through preliminary identification. J13 and Y7 were inoculated into culture medium which added with PbCO
₃
and carried out activation test of lead in precipitation fraction on sample II. The results showed that the content of lead in active fraction of culture medium was more than that of sample II. The available lead content in J13 and Y7 culture medium were 1.809 mg L
^-1
and 1.513 mg L
^-1
respectively, 1.022 mg kg
^-1
and 0.996 mg kg
^-1
in sample II respectively. This may be related to adsorption of part of Pb
²⁺
by Soils; Meanwhile, both of the pH value decreases with the increase of Pb
²⁺
content. It indicated that the activation efficiency of bacterial strain J13 and Y7 correlated to their ability to produce acid.