Abstract
This study investigated changes in the antioxidant system of Phaseolus vulgaris plants grown in a medium contaminated with heavy metals (Cu, Cd, Zn) and Pseudomonas spp., with the aim of evaluating the bioremediation effect of the bacterial consortium. The results showed that in the control group, antioxidant activity was 25% in the roots, 24% in the leaves, and 27% in the stems. Upon exposure to copper (Cu 0.01), these values increased significantly to 59%, 56%, and 57%, respectively, indicating activation of the antioxidant system in response to severe oxidative stress. When the copper concentration was reduced (Cu 0.001), antioxidant activity decreased to 14% in roots, 11% in leaves, and 18% in stems. In the case of cadmium (Cd 0.01), the values were 19%, 15%, and 18%, whereas in the Cd 0.001 treatment, an increase to 25% in leaves and 31% in stems was observed. Antioxidant activity decreased under zinc (Zn 0.01) exposure and amounted to 11% in roots, 4% in leaves, and 14% in stems, while the lowest values were recorded at Zn 0.001 (3%; 1.73%; 8%). The use of the Pseudomonas spp. consortium increased plant resistance to heavy metals and contributed to the stabilization of the antioxidant system. Overall, the results demonstrate that these bacteria can be used as an effective bioremediation agent by biosorbing heavy metal ions and reducing oxidative stress in plants.