Asian Journal of Biotechnology and Bioresource Technology

Piggery wastes can be reservoirs of heavy metals and high microbial loads that pose environmental and public health risks. Bioremediation is the most efficient, eco-friendly and cost-effective technology for the transformation of contaminants. This study evaluated the bioremediation potential of indigenous bacteria isolated from piggery effluents collected from six farms in the Owo local government area, Nigeria. Bacterial isolates (Escherichia coli, Klebsiella sp., Pseudomonas sp. and Staphylococcus sp.) were recovered and characterised by standard cultural, morphological and biochemical tests. Isolates were incubated in nutrient broth amended with target metal salts, and metal concentrations were monitored weekly for 28 days by atomic absorption spectrophotometry. Pseudomonas sp. showed the greatest reduction in selected heavy metals, while Escherichia coli demonstrated a notable reduction in zinc. These findings indicate that indigenous piggery bacteria, particularly Pseudomonas spp., have measurable potential for laboratory-scale bioremediation of metal-contaminated wastes. We recommend follow-up studies using quantitative molecular identification, controlled microcosm/mesocosm trials and assessment of safety (e.g., antibiotic resistance profiling) before field application. It may be concluded from this study that Pseudomonas sp., Klebsiella sp, E. coli, and Staphylococcus sp. were associated with the effluent of piggery in Owo. Moreover, Pseudomonas sp. had higher bioremediating activity on the selected heavy metals.