Alleviation of cadmium stress in rice by inoculation of Bacillus cereus

Heavy metal resistant bacteria are of great importance because they play a crucial role in bioremediation. In the present study, 11 bacterial strains isolated from industrial waste were screened under different concentrations of cadmium (Cd) (100 mu M and 200 mu M). Among 11 strains, the Cd tolerant Bacillus cereus (S6D1-105) strain was selected for in vitro and in vivo studies. B. cereus was able to solubilize potassium, and phosphate as well as produce protease and siderophores during plate essays. Moreover, we observed the response of hydroponically grown rice plants, inoculated with B. cereus which was able to promote plant growth, by increasing plant biomass, chlorophyll contents, relative water content, different antioxidant enzymatic activity such as catalase, superoxide dismutase, ascorbate peroxidase, polyphenol oxidase and phenylalanine ammonia-lyase and reducing malondialdehyde content in both roots and leaves of rice plants under Cd stress. Our results showed that the B. cereus can be used as a biofertilizer which might be beneficial for rice cultivation in Cd contaminated soils.

Automated summary

In this study, a cadmium-tolerant Bacillus cereus strain was isolated from industrial waste and shown to promote the growth of rice plants and enhance antioxidant enzyme activity under cadmium stress, suggesting its potential as a biofertilizer for rice cultivation in cadmium-contaminated soils.