Cadmium phytoremediation performance of two species of Chlorophytum and enhancing their potentials by cadmium-resistant bacteria

This study compared the cadmium phytoextraction efficiency of Chlorophytum comosum and Chlorophytum amaniense, and whether cadmium-resistant bacteria inoculation can enhance plant growth and cadmium uptake. Pot experiments were performed for nine weeks in greenhouse conditions. The results found that C. amaniense had a higher shoot biomass than C. comosum, while the root biomass of C. comosum was higher than that of C. amaniense. Micrococcus sp. MU1 boosted biomass production of C. comosum and C. amaniense under cadmium stress conditions. Cadmium accumulated more in the shoot and root of C. comosum than in C. amaniense. Inoculation of Micrococcus sp., Arthrobacter sp. and co-culture of these bacteria stimulated cadmium content in the shoot and root tissues. However, the highest cadmium extraction amount was found in C. comosum inoculated with Micrococcus sp. due to its higher plant dry weight. In addition, the cadmium phytoextraction efficiency of C. comosum was higher than that of C. amaniense, but the translocation of cadmium from the root to shoot in both plants were not significantly different (p < 0.05). An application of these cadmium-resistant bacteria stimulated cadmium phytoextraction efficiency and cadmium translocation in both plants. This study establishes the feasibility of using a combination of cadmium-resistant bacteria and Chlorophytum spp. to enhance cadmium phytoextraction of cadmium-contaminated soil.