Evaluation of a consortium of heavy metal-resistant bacteria in corn plants grown in contaminated soil

Abstract Soil pollution with heavy metals poses a significant ecological challenge globally. Bacteria can be utilized for the bioremediation of heavy metals in the soil. This study evaluated the bioremediation potential of a bacterial consortium comprising Pseudomonas putida R2.13, Bacillus megaterium RK.3, and Stenotrophomonas maltophilia RG.3 on corn plants grown in heavy metal-contaminated soil. The study was conducted in two activities: the first involved an inoculant test assessing the growth of corn sprouts under varying inoculant levels (0, 10, 20, and 40 mL) and different concentrations of heavy metals (Hg, Cr, and Pb). The second was a greenhouse study employing a factorial randomized block design with the same inoculant levels and six distinct growing media compositions: a mixture of tailings, unpolluted soil, and compost (%). Results indicated that a 40 mL inoculant significantly mitigated Hg toxicity (up to 150 mg L −1 ), Cr (30 mg L −1 ), and Pb (1500 mg L −1 ) in corn sprouts. Furthermore, applying 40 mL of the bacterial inoculant in growing media M4 (10:45:45) resulted in a 58.63% remediation in Hg concentration from 49.53 mg L −1 , accompanied by a decrease in soil pH and bacterial population. These findings suggest that bacterial consortia can be applied for soil bioremediation and agricultural purposes.