Isolation and Identification of Native Lithium-Resistant Bacteria from Electronic Waste Contaminated sites: A focused Investigation on Tolerance Assessment with Potential Lithium Bio-recovery Application
S. Priyadarsini, Alok Prasad Das
Abstract
Bioleaching offers an eco-friendly approach for the sustainable and efficient recycling of lithium from spent mobile batteries by utilizing the natural metabolic activities of microbes. This study investigates the isolation and identification of native lithium-resistant bacteria from e-waste contaminated sites. Four bacterial strains with distinct morphological characteristics were isolated on nutrient agar (NA) plates enriched with 100 mM lithium chloride. Further, the isolates were screened for their lithium tolerance activity by subculturing them on different lithium concentration plates ranging from 100 to 500 mM at 32 °C and pH 7 for 24 hours. The most lithium-resistant strain proficient in growing at 500 mM Li concentration was identified through 16s rRNA sequencing as Cellulosimicrobium funkei with NCBI gene bank accession number PP741864. The morphometric structure of the identified bacterial strain was examined using scanning electron microscopy (SEM), and reported to be rod-shaped with cells arranged individually in small clusters, with a size range of approximately 3–5 micrometers in length. The findings revealed that the e-waste contaminated site harbored native bacterial species with prominent tolerance toward Li, highlighting the potential application of the isolated bacterial strain in the bio-recovery of Li from spent LIBs, offering a greener and more sustainable solution.