Evaluating the efficiency of indigenous soil bacterial strains for heavy metal removal

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Significant quantities of toxic heavy metals are regularly deposited into soil environments every day as a result of industrial and human activities, as well as natural emissions. Today, biological methods for reducing heavy metal pollution are becoming increasingly common as an innovative approach to combating heavy metal pollution. The purpose of this study was to identify soil bacteria capable of removing heavy metals and to explore the potential of native bacteria in the bioremediation process. During this experiment, various soil samples were collected from several sites (river bank Rvs1, bus station Bt2, agricultural site Ag3, landfill Gr4 and construction site Cn5). Five bacterial strains were isolated from soil samples using a conventional serial plate dilution method. Morphologically distinct colonies were selected and purified during incubation. Pure cultures of bacterial colonies were established and maintained as slant cultures. Depending on preliminary physical, chemical and morphological characteristics, isolates RvsS1, Bt2, Ag3, Gr4 and Cn5 were compared with the bacterial species: “Proteus”, “Staphylococcus”, “Pseudomonas”, “Bacilli” and “Klebsiella” respectively. Bacterial isolates were examined for their uptake of Cu, Cd and Pb in flask bioreactors. Strains RV1, Bt2, Ag3 and Gr4 removed 48.7%, 25.6%, 59.8% and 23.5% of lead, respectively. The removal efficiency of isolate Cn5 was 35.68% for lead and 48.53% for copper. Thus, the data demonstrate that the use of indigenous bacteria is potentially effective in the bioremediation of heavy metals. Keywords: BIOREMEDIATION, MICROORGANISMS, HEAVY METALS, LOCAL BACTERIA, ISOLATES, STRAINS, ABSORPTION