We have isolated a Pseudomonas aeruginosa strain designated CHL004 whi
ch is able to remove lead from solidified media and soil. The process
for testing removal was generally the same for all experiments. A piec
e of sterile filter paper was placed on the surface of a plate contain
ing solidified media and lead carbonate or lead contaminated soil and
incubated at 29 degrees C for 30 days. Lead was removed from yeast mal
t plates but generally not from R2A plates. Dextrose was shown to be a
critical component in the YM; without it almost no lead was removed.
Sucrose, maltose and lactose could not be substituted for the dextrose
although these carbon sources allowed for survival and growth of the
isolate. In order to study the initial kinetics of lead uptake, lead n
itrate was used in an aqueous environment. The rate of uptake of lead
nitrate by CHL004 was very rapid initially then decreased greatly. Sod
ium azide treated cells did not remove lead. The removal of lead from
an urban soil was affected by the pH of the soil. The pH of the soil i
n YM was 6.9 and 3.3% of the total lead in the soil was removed. When
the pH was adjusted to a pH of 5, 8% of the total lead was removed but
at a pH of 6, 6.4% was removed.