Biosorption of Lead (Pb) by Pb-Resistant Microorganisms Isolated from E-Waste Dump Yard – A Strategy for Microbiological Bioremediation

Electronic waste (E-waste) is a major source of environmental pollution due to its heavy metal content.Microbial bioremediation offers a promising strategy for sustainable E-waste management.This study aimed to isolate and identify bacteria and fungi from an E-waste dump yard, evaluate their heavy metal resistance, and assess their biosorption potential and biosafety.Microbes were isolated from an E-waste dump site and characterized morphologically and biochemically.Three bacterial isolates (EWB1, EWB2 and EWB3) were identified as Gram-positive Bacillus spp., and four fungal isolates were identified as Aspergillus fumigatus, A. niger, A. flavus, and Penicillium sp.The isolates were screened for resistance to cadmium (Cd), cobalt (Co), and mercury (Hg).Lead (Pb) biosorption potential was quantified using inductively coupled plasma-optical emission spectrometry (ICP-OES).The most efficient bacterial isolate, EWB1, was further identified via 16S rRNA sequencing.Toxicity assays were conducted using Artemia nauplii and zebra fish larvae.EWB1 demonstrated the fastest coagulant formation and the highest Pb biosorption capacity (216.8 mg/l).EWB2 showed the highest resistance to Hg at 600 mg.Among fungi, EWF4 exhibited resistance to all three metals (Cd, Co, Hg).16S rRNA analysis identified EWB1 as Bacillus subtilis, and the sequence was submitted to NCBI.Toxicity testing confirmed that B. subtilis (EWB1) was non-toxic to aquatic model organisms.B. subtilis (EWB1) isolated from E-waste shows significant potential for heavy metal biosorption and is non-toxic, indicating its suitability as a bioremediation agent for E-waste degradation.