Enhanced uptake of Cd, Cr, and Cu in Catharanthus roseus (L.) G.Don by Bacillus cereus: application of moss and compost to reduce metal availability

Heavy metals (HMs) being the notorious and toxic are being introduced into the environment credited to natural and anthropogenic activities. The use of ornamental plants is being ignored as potential candidates for HMs phytoremediation. In this study, pot experiments were conducted on Catharanthus roseus (L.) G.Don to evaluate selected heavy metals tolerance and accumulation potential with reference to the bacterial endophyte (Bacillus cereus) and organic amendments (moss and compost at 5% v/v). Results indicated improvement in uptake of Cd (230 mg kg(-1)), Cu (229 mg kg(-1)), and Cr (458 mg kg(-1)) by C. roseus with B. cereus. The concentration of Ni and Pb was found highest in controls (without strain) that were 420 and 904 mg kg(-1), respectively. Conversely, the addition of organic amendments enhanced biomass production, as compared to controls, 441, 471, and 763% by peat moss (T3), compost (T4), and peat moss + compost + inoculum treatments (T6), respectively, while reduction of plant HMs content was observed. Microbial-aided phytoremediation/phytoextraction could be a potential method for removal of Cd, Cr, and Cu, while organic amendments can significantly improve plant growth in the presence of heavy metals.