Potential of IAAT-3 Bacterial Isolate from Coal Mine Acid Mine Drainage Treatment Pond for Iron (Fe) Removal

The IAAT-3 bacterial isolate, recovered from a coal mine acid mine drainage (AMD) treatment pond, was evaluated for its bioremediation potential in reducing iron (Fe) concentrations. Experiments conducted from January to May 2025 examined the isolate’s growth kinetics in Nutrient Broth supplemented with 25 ppm Fe and its Fe removal efficiency. A completely randomized design with three replicates and a negative control (Fe-free medium) was employed. The isolate exhibited significantly enhanced growth in the Fe-amended medium, attaining an optical density at 600 nm (OD₆₀₀) of 1.503 markedly exceeding the control indicating effective Fe tolerance and potential utilization as a micronutrient. Following 30 days of incubation, atomic absorption spectroscopy revealed a 94.79% reduction in Fe concentration. Phenotypic characterization confirmed that IAAT-3 is a Gram-positive, rod-shaped (bacillary) bacterium capable of forming central endospores. These results demonstrate the robust potential of IAAT-3 as an environmentally friendly, low-cost bioremediation agent for passive treatment of iron-contaminated acid mine drainage in coal mining-impacted environments.