ANNOUNCEMENTS
Heavy metal contamination in soil poses a critical environmental challenge, adversely affecting human health, agriculture, and ecosystems. This study evaluates the bioremediation potential of five zinc-solubilizing bacterial strains i.e. C10A, C9A, A5 (Trans), A5 (MD), and A6 as a sustainable and eco-friendly approach to mitigate toxicity caused by heavy metal pollutants such as lead, cadmium, arsenic, and chromium. A multi-dimensional experimental framework was employed, including Minimum Inhibitory Concentration (MIC) testing, optical density (OD) analysis, indole-3-acetic acid (IAA) production, siderophore activity, colony-forming unit (CFU) assessments, and Gram staining.
Among the tested metals, lead demonstrated the highest compatibility, supporting sustained microbial growth across the strains, which exhibited exceptional tolerance and high IAA and siderophore production. A6 shown high resistivity with strong growth while C10A had slow growth but at the same time high resistivity across heavy metals except for Chromium. Pb-specific MIC tests in distilled water revealed increasing precipitation with concentration across all strains and highlighting the importance of physicochemical context in tolerance evaluation. Gram staining results confirmed strain-specific morphological responses, such as biofilm formation and cell clustering under Pb stress, indicating adaptive survival strategies.
The study also revealed promising tolerance to arsenic and cadmium, especially in strains like A6, C10A and C9A, opening avenues for future research in arsenic-specific detoxification and cadmium biosorption. Ongoing ICP-MS analysis of Pb samples aims to quantify biosorption capacity and validate microbial remediation mechanisms. These findings contribute significantly to the field of microbial-assisted bioremediation and offer practical solutions for the restoration of contaminated soils, with broader implications for environmental sustainability and agricultural productivity.
Keywords: Bioremediation, Zinc-Solubilizing Bacteria, Heavy Metals, Lead Tolerance, Cadmium, Arsenic, Chromium, MIC, IAA, Siderophore, Gram Staining, Soil Restoration, Environmental Sustainability.
