Prevention of Cadmium Contamination by Microbial Inoculant and Its Potential Mechanism

Abstract

Cadmium is the main heavy metal contaminant of food in the world. The extent of cadmium pollution in peanut in China remains unclear. To determine the cadmium pollution level in peanut, samples from the main producing regions in China were assessed. The findings revealed that the cadmium pollution level in Chinese peanuts was relatively low. Moreover, the Aflatoxin Rhizobia Couple B. amyloliquefaciens, B. laterosporu, B. mucilaginosus, E. ludwiggi (ARC-BBBE) microbial inoculants on cadmium contamination in peanut were evaluated. The fertilization methods were categorized into conventional fertilization and conventional fertilization supplemented with 60 kg/hectare of microbial inoculant ARC-BBBE as the base fertilizer. The cadmium contents in the soil and peanut plant parts were detected and analyzed. The results demonstrated that the microbial inoculant ARC-BBBE significantly reduced the total cadmium content in peanut, as well as the available cadmium and exchangeable cadmium in soil. Furthermore, the pH and urease and alkaline phosphatase activities in soil were significantly enhanced, suggesting that the microbial inoculant ARC-BBBE decreased cadmium content in soil and reduced the cadmium uptake by plants through a combination of the action of the bacteria itself and the secretion of extracellular substances. This ultimately achieves the goal of reducing the cadmium content in peanut seeds.