Enhanced phytoremediation of soil heavy metals by arbuscular mycorrhizal fungi, Bacillus subtilis and CO2 release in Typha domingensis rhizosphere.

Phytoremediation is a green, cost-effective alternative to established soil remediation technologies. The recent bacterial-mycorrhizal revolution in combination with plants has resulted in significant advances in our knowledge of metal removal in polluted soils. However, depending on the biomass and size of the roots, each plant differs in its capacity to remove heavy metals. The study's objective was to study the effects of bacteria, mycorrhiza, papyrus, and CO₂ release on lead (Pb) and cadmium (Cd) removal from the soil. Six different combinations (mycorrhiza, Bacillus 10 mL, Bacillus 100 mL, mycorrhiza + Bacillus 10 mL, mycorrhiza + Bacillus 100 mL, and control) were used in the experiment. The results showed that the combination of the mycorrhiza with bacillus 100 mL showed more profound increases in CO₂ release and polysaccharide content (2.84 mg CO₂ g⁻¹ dry soil, 0.90 mg) respectively. More importantly, the highest concentrations of Cd and Pb were found in the roots of mycorrhiza + Bacillus 100 mL (18.26 mg kg⁻¹ and 155.22 mg kg⁻¹, respectively), implying that microbes played a concrete role in the phytoextraction process. The highest values of the translocation factor (TF) and biological accumulation factor (BAF) for Cd were found at Bacillus 100 mL (3.99) and (75.54), respectively, suggesting efficient translocation and excessive Cd accumulation in the plant. For Pb, Bacillus 100 mL and mycorrhiza + Bacillus 100 mL had the highest TF and BAF, which were 0.49 and 6.08 respectively. In conclusion, the removal of Cd and Pb was linked to the maximum bacterial cell density, mycorrhizal activity, and CO₂ emission, resulting in unique phytoremediation in Pb–Cd contaminated papyrus rhizosphere soils. [ABSTRACT FROM AUTHOR]