Isolation and molecular characterization of heavy metal tolerant bacteria from Kofar Ruwa scrap metal dump site in Kano Metropolis

Abstract

This study aimed at molecular detection of heavy metal tolerant bacteria from Kano, Kofar Ruwa scrap metal dump site, as heavy metals are one of the major setbacks to many forms of lives and their presence in the ecosystem is rapidly increasing due to anthropogenic activities, rampant scrap metal waste disposal and other industrial wastes. Bacteria were found to be among many microorganisms that are able to tolerate many heavy metals and can reduce their toxicity or even convert them to useful resources. The heavy metal content of some soil samples analyzed using Atomic Absorption Spectrophotometry (AAS). Standard methods of enrichment culture and colony count were used to isolate a total of 12 bacterial species. Using 16S rRNA gene sequence based on molecular system, the 12 isolates were identified and grouped into one genus (Bacillus). It was also observed and reported from the results that the concentration of heavy metals (Pb, Zn, Cu, Cd, and Cr) found to be high above the WHO permissible limits (Copper-2.0, Zinc-3.0, Lead-0.4, Chromium-0.05 and Cadmium-0.03). Therefore, the bacterial isolates capable of surviving at such levels of heavy metals could have potential application in the bioremediation, bioleaching, human carcinogens substances and soil infertility of heavy metal contaminants . It is therefore, recommended that further research on these bacterial species should be carried out to address their significance for the public health interest and humanity in general.