Phenol Contamination and Microbial Diversity in Soil Samples from Mechanic Workshops in Gombe Metropolis: Implications for Bioremediation

Abstract

Environmental contamination from phenol, a priority pollutant, is a growing concern due to its toxicity and persistence in ecosystems. In Gombe metropolis, mechanic workshops contribute significantly to phenol pollution through hydrocarbon spills, necessitating studies on microbial degradation as a potential bioremediation strategy. This study investigates phenol contamination levels in soil samples from mechanic workshops in Gombe metropolis and assesses microbial diversity with a focus on their potential for phenol degradation. Soil samples were collected from 13 mechanic workshops and analyzed for phenol concentrations using FeCl₃ spectrophotometric methods. A microcosm enrichment approach with kill and non-kill experimental setups was employed to evaluate microbial degradation rates. Bacterial strains were isolated and identified based on morphological and biochemical characterization, referencing Bergey’s Manual of Systematic Bacteriology. Phenol concentrations in soil samples ranged from 0.082 mg/ml to 0.369 mg/ml, showing significant variation across locations. The t-test analysis (T-Value = -0.31, DF = 8, P-Value = 0.763) indicated no significant difference in degradation rates between kill and non-kill setups. A total of 14 bacterial strains were isolated, with six identified biochemically. The dominant isolates included Pseudomonas spp., Enterobacter aerogenes, Klebsiella pneumoniae, Staphylococcus spp., and Micrococcus spp., known for their phenol-degrading potential. This study highlights the extent of phenol contamination in soils from Gombe mechanic workshops and identifies native bacterial strains with bioremediation potential. Future research should explore optimizing microbial consortia for enhanced phenol degradation in contaminated environments.