Background & Objectives: Lead is one of the most widespread heavy metals in the environment. Identifying resistant strains to this toxic is the first step for their application in bioremediation process. The aims of this study were to isolate and identify lead resistant bacteria from contaminated soils near gas stations in Jahrom city and to evaluate lead bioremoval by these bacteria. Methods: In this experimental study, 9 samples were taken from soils around 3 gas stations in Jahrom city. Isolation of resistant bacteria was performed through primary enrichment and then cultivation on LB broth solid medium containing lead acetate. Bacteria were identified by usual biochemical tests. MIC test was done to obtain the minimum concentration of lead that prevents bacterial growth. Growth rate of resistant bacteria at different concentrations of lead acetate in LB broth was evaluated using spectrophotometer at 600 nm. Results: Bacillus, Pseudomonas, Corynebactereium, Staphylococcus, and Escherichiacoli as lead resistant bacteria eliminated 89.66, 87.97, 87.64, 70.82, and 60.35% of lead, respectively. MIC was 12.5 mmol per liter for Bacillus, Pseudomonas and Corynebactereiumand6.25 mmol per liter for Staphylococcusand Escherichia coli. The highest growth of Bacillus and Corynobacterium was observedat 0.7 g lead acetate per liter while for Pseudomonas it was occurredat 0.4 g lead acetate per liter. Conclusion: Results of current study showed that Bacillus, Pseudomonas, and Corynebacteriumhave high resistance to lead and they are appropriate options for lead bioremediation.
Kafilzadeh F, Afrough R, Mojoodi N. Isolation and Identification of Lead Resistant Bacteria from Contaminated Soils near Gas Stations in Jahrom City. j.health 2013; 4 (2) :110-121 URL: http://healthjournal.arums.ac.ir/article-1-87-en.html