This work focused on the ability of six indigenous microorganisms (
Arthrobacter nicotiniae,
Bacillus substilis
,
Klebsiella pneumoniae
,
Proteus mirabilis
,
Trichophyton interdigtae
and
Onychocola canadensis
) isolated from
contaminated agricultural soil obtained from Ishiagu forest in Ebonyi State, Nigeria for the removal of lead (Pb) ion from
the soil. The weights of organisms, nutrient dosage, temperature, pH and stirring frequency were optimized for the removal
of the metal ion from the soil. The data revealed that
Bacillus subtilis,
Klebsiella pneumoniae and
Arthrobacter nocotiniae
were found to reduce the metal concentration below recommended standard at time 14 days with respective efficiencies
of 58.25 %, 60.64 % and 60.80 % at the 14 days; and 78.25 %, 76.19 % and 79.78 % at time 35 days; while
Proteus
mirabilis,
Onychocola canadensis and
Trichophyton interdigtae were found to reduce the metal concentration at time 21
days with respective efficiencies of 51.74 %, 44.65 % and 48.08 % at time 21 days; and 59.67 %, 51.13 % and 55.27 %
at time 35 days. The study showed that the organisms can be utilized to remove Pb ion from the contaminated soils.
Arthrobacter nicotiniae showed the greatest removal capacity with time, followed by
Bacillus substilis, and then
Klebsiella
pneumoniae; before
Proteus mirabilis,
Trichophyton interdigtae and
Onychocola canadensis in that order.