Determination of Total Petroleum Hydrocarbon Composition and Screening for Metallotolerant Bacteria from Polluted Effluent Discharge in Kaduna Metropolis, Nigeria

The release of heavy metals into aquatic systems results in various environmental challenges. The combined presence of hydrocarbons and heavy metals within the environment also poses a health risk to humans, plants, and animals. This study aimed to screen for metallotolerant bacteria from a polluted effluent discharge in Kaduna metropolis, Nigeria. Physicochemical assessment, determination of total petroleum content, and heavy metal screening of the wastewater samples were conducted using standard protocols. Metallotolerant bacteria were screened and identified using standard methods. It was revealed from the result that, on the total petroleum hydrocarbons (TPHs), eicosane had the highest detectable similarity with percentage quality (99%), while oxasiloxane, 1,1,3,3,5,5,7,7,9,9,11,11,13,13,15,15-hexadecamethyl (50%) was the lowest. Lead had the highest concentration of 0.95±0.017 Mg/L, while zinc had the lowest value, 0.057±0.00 mg/L. The bacterial species identified were Escherichia coli, S. aureus, Klebsiella sp., Pseudomonas sp., and Bacillus species, respectively. Furthermore, the tolerance assay results showed that Pseudomonas species had the maximum tolerance for Cu (0.72 mg/mL), Bacillus species for Pb (0.79 mg/mL), Escherichia coli for Zn (0.76 mg/mL), and Staphylococcus aureus for Fe (0.92 mg/mL), respectively. Based on the maximum tolerance exhibited by these bacterial isolates to heavy metals, this study proved they are good candidates, especially isolates of (Staphylococcus aureus, Pseudomonas species, and Bacillus species) for use in bioremediation and bioaugmentation of heavy metals in polluted industrial sites.