Cadmium and lead tolerant bacteria isolated from industrial waste water

Abstract

An in vitro study was conducted to isolate, identify and characterize heavy
metal resistant bacteria from industrial waste water and to determine their
tolerance capacity to cadmium and lead. Different morphological, physiological
and biochemical tests were carried out to identify the bacterial isolates in the
waste water. A total of eight bacterial isolates viz., Staphyllococcus intermedius,
Pseudomonas aeruginosa, Bacillus cereus, Bacillus subtilis, Escherichia coli,
Acinetobacter baumanii, Pseudomonas flavescens and Acinetobacter lwofii were
identified from metal polluted tannery and steel industrial areas. Bacterial
response to cadmium tolerance was determined by treating them with CdCl2
solution at a rate of 1, 2, 2.5 and 5 μg/ml. In case of lead tolerant bacteria, PbCl2
solution was applied at a rate of 0.05, 0.125, 0.2 and 0.5 μg/ml. Pseudomonas
aeruginosa isolated from waste water of steel industries and Bacillus cereus from
tannery area was found to be the most tolerant species to the different doses of
cadmium and lead. The study indicated that Pseudomonas aeruginosa and Bacillus
cereus could be good candidates for the treatment and elimination of heavy
metals from industrial waste water. The present study may be helpful to the
bioremediation of heavy metals in the contaminated environment.