Cadmium phytoremediation potential of Deenanath grass (Pennisetum pedicellatum) and the assessment of bacterial communities in the rhizospheric soil

Phytoremediation technology is gaining excessive consideration as a promising method for heavy metal remediation from contaminated soil. In the present research study, a greenhouse trial was performed to assess the proficiency of Pennisetum pedicellatum as a potential plant species for the remediation of cadmium from the soil. Four sets of treatments i.e., (T_o) control, (T₁) 25 ppm, (T₂) 50 ppm, and (T₃) 100 ppm were studied till 60 days. Soil and plant samples were collected at a regular interval of 15 days after the seed sowing and analysed for different physicochemical properties and Cd concentrations from each treatment. The cadmium uptake was studied in the roots and shoots independently to examine the cadmium accumulation in P. pedicellatum. The present study showed that P. pedicellatum accumulated cadmium mostly in their roots compared to the shoots resulting in the accumulation of Cd from the soil. The finding indicates that P. pedicellatum is a virtuous plant species to restore cadmium-contaminated soil. It effectively banished 83% of Cd from the 100 ppm spiked soil at the end of 60 days. The microbial characterization of rhizospheric soil was also done using serial dilution and spread plate procedures to determine the presence of bacterial species in the rhizospheric soil. Seven bacterial strains were isolated from the soil and were further assessed for their biochemical, molecular, and phylogenic characteristics. The 16S rRNA sequencing analysis confirmed the presence of different bacterial species such as Alcaligenes sp., Bacillus drentensis, Bacillus subtilis, Bacillus foraminis, Bacillus wudalianchiensis, Bacillus amyloliquefaciens, and Planococcus ruber. This study concluded that phytoremediation using P. pedicellatum is a fascinating and compelling green technology for the remediation of cadmium from soil.