CHARACTERIZATION OF BACTERIAL COMMUNITIES IN AUTOMOBILE WORKSHOPS: A STUDY ON BOJI-BOJI OWA METROPOLIS

This study investigates the bacterial diversity, antibiotic resistance profiles, and physicochemical characteristics of soil samples collected from selected automobile workshops in Boji-Boji Owa Metropolis, Delta State, Nigeria. The physicochemical parameters, presented in Table 4.1, revealed acidic soil conditions, moderate levels of organic matter, and elevated electrical conductivity, suggesting contamination from petroleum-based pollutants and workshop waste. Microbiological assessments, including Total Heterotrophic Bacterial Count (THBC) and Total Bacterial Count (TBC), were performed using Nutrient Agar and MacConkey Agar, with the results shown in Tables 4.2 and 4.3 respectively. These counts confirmed high microbial loads across all workshop sites. Biochemical and morphological characterization of bacterial isolates, summarized in Table 4.4, identified a range of Grampositive and Gram-negative bacteria. These included Bacillus licheniformis, Bacillus spp., Proteus spp., Klebsiella spp., Clostridium spp., Citrobacter spp., Enterobacter spp., and Serratia spp. The prevalence analysis (Table 4.5) indicated that Bacillus species were the most frequently encountered, likely due to their resilience in oil-contaminated environments. Antibiotic susceptibility testing (Table 5) showed varied resistance patterns among the isolates. While Gram-positive bacteria exhibited higher sensitivity to certain antibiotics, Gram-negative isolates demonstrated notable resistance to commonly used drugs. Several strains exhibited multidrug resistance, underscoring environmental selective pressures from prolonged exposure to pollutants. These findings highlight the environmental and public health risks posed by unmanaged waste in automobile workshops. The presence of adaptable, resistant bacteria also points to the potential use of native isolates in bioremediation strategies aimed at restoring polluted urban soils.