Intensifying Cadmium remediation: the impact of synergy between Crambe abyssinica and plant growth-promoting microorganisms

Abstract

Cd, a toxic metal, is naturally found in the environment and is exacerbated by human activities such as mining, agriculture, and industrial processes. Its contamination in soils poses serious risks to human health and ecosystems, prompting the need for effective remediation strategies. This study focuses on the use of Crambe abyssinica, an oilseed plant known for its tolerance to adverse environmental conditions, including Cd contamination, for phytoremediation of contaminated soils, associated with bioremediation through plant growth-promoting microorganisms. The study involved growing Crambe in vitro. Methods included seed asepsis, substrate contamination with various Cd concentrations, and inoculation with beneficial microorganisms such as Bradyrhizobium japonicum, Bacillus subtilis along with Bacillus megaterium, Azospirillum. brasilense, Pseudomonas fluorescens, and Trichoderma harzianum. Data such as plant length and root area were measured, and the nutrient and Cd content in the plants were assessed. Results indicated that inoculation with microorganisms significantly enhanced the nutrient content in Crambe plants, even under different Cd concentrations. Notably, A. brasilense and P. fluorescens were particularly effective, not only increasing nutrient uptake but also enhancing Cd accumulation in the plants, which is crucial for phytoremediation. The presence of these microorganisms also led to a significant reduction in the Cd concentration in the substrate, showcasing their potential in bioaugmentation. The study highlights the efficacy of using Crambe abyssinica in conjunction with specific microorganisms for the remediation of Cd-contaminated soils. The synergistic effects of these plant-microorganism interactions not only promote plant growth and health but also enhance the phytoextraction of Cd, offering a sustainable solution to soil contamination. Future research should focus on optimizing these interactions and exploring their applications in larger-scale environmental remediation projects.