Bacillus altitudinis Mediated Lead Bioremediation for Enhanced Growth of Rice Seedlings

Lead (Pb) is a hazardous environmental pollutant that threatens soil health, water quality, and agricultural productivity. Plant growth-promoting rhizobacteria (PGPRs) mediated bioremediation is considered as an eco-friendly approach for agro-environmental sustainability. This study investigated the Pb bioremediation potential of Bacillus altitudinis (IHBT-705). The results revealed that IHBT-705 strain tolerated upto 15 mM of Pb, possessed 96% Pb bioaccumulation efficiency, and also maintained its plant growth-promoting (PGP) traits under Pb stress. Furthermore, IHBT-705 strain treated with 15 mM Pb solution (IHBT-W) and soil containing 15 mM Pb treated with IHBT-705 inoculum (IHBT-S) ameliorated the detrimental effects of Pb stress. Both IHBT-W and IHBT-S treatment significantly improved the shoot length, root length, total roots, chlorophyll content, and antioxidants enzyme activity of the rice seedlings as compared to the seedlings treated with 15 mM Pb solution (Pb-W) and soil containing 15 mM Pb (Pb-S). Also, IHBT-W and IHBT-S treatment decreased the Pb content in the rice plant by 97 and 96% over their respective Pb-W and Pb-S plants. Overall, our research underscores the remarkable Pb bioremediation potential of IHBT-705, offering a promising avenue for dual function, i.e. improving soil health and promoting plant growth under Pb contamination.