Effects of Bacillus subtilis and nanohydroxyapatite on the metal accumulation and microbial diversity of rapeseed (Brassica campestris L.) for the remediation of cadmium-contaminated soil

Abstract

This study investigated the effects of the co-application of Bacillus subtilis and nanohydroxyapatite (NHAP) on plant growth, soil cadmium (Cd) dynamics, and the microbiological characteristics (such as enzyme activity and bacterial species richness) of the rhizosphere soil. Rapeseed was used as a model plant in pot experiments. Different concentrations of B. subtilis and 0.5% NHAP were applied alone and in combination to Cd-contaminated soil. The Cd contents in soils and plants as well as the rhizospheric microorganism diversity were assessed. The addition of B. subtilis or NHAP alone increased the soil Cd content and decreased the plant Cd content, while their co-application more effectively increased the soil and plant Cd contents than either treatment alone. B. subtilis and NHAP reduced the plant Cd content by 43.15-57.04% compared with that in the control. Rhizosphere community richness and bacterial diversity were significantly increased after co-application of B. subtilis and NHAP. Co-application of B. subtilis and NHAP effectively promoted rapeseed growth and improved Cd-contaminated soil remediation.

Bacillus subtilisimpact on plant growth, soil health and environment: Dr. Jekyll and Mr. Hyde

“…It can be used as a potent geomicrobiological stabilizer for immobilization of Pb, Sb, Ni, Cu and Zn in alkaline soils. The application of nanohydroxyapatite (NHAP) along with B. subtilis to cadmium contaminated soil improved soil remediation and increased rhizospheric community (Liu et al, 2018). UV-mutated species B. subtilis 38, served as an efficient sorbent of Hg, Cr, Cd and Pb (Wang et al, 2019).…”

A review on nanobioremediation approaches for restoration of contaminated soil

“…The triumphant elimination of Cd in Cd-polluted water illustrated the competence of Pseudomonas aeruginosa improved Cd bioreduction which in turn hasten the cadmium sulfide (CdS) NPs biosynthesis (Raj et al, 2016). Likewise, the removal and bioremediation of Cd from Cd-polluted soils also evaluated (Liu et al, 2018b). The authors demonstrated that the co-treatment of Bacillus subtilis and nano-hydroxyapetite (NHAP) efficiently eliminated the Cd contamination, encouraging the propagation of microbial community of rhizosphere along with the diversity of bacteria in the remediated soil (Liu et al, 2018b).…”

“…Likewise, the removal and bioremediation of Cd from Cd-polluted soils also evaluated (Liu et al, 2018b). The authors demonstrated that the co-treatment of Bacillus subtilis and nano-hydroxyapetite (NHAP) efficiently eliminated the Cd contamination, encouraging the propagation of microbial community of rhizosphere along with the diversity of bacteria in the remediated soil (Liu et al, 2018b). The evaluation of somewhat variable biofunctionalized approach including polyvinylpyrrolidone (PVP)coated iron oxide NPs intermingled with Halomonas sp.…”

A comprehensive review on nanobiotechnology for bioremediation of heavy metals from wastewater

“…Biofunctionalization of metallic nanoparticles >90% removal rate [50] Cadmium Bacillus subtilis Biofunctionalization of Nanohydroxyapatite 43.15%-57.04% increased removal efficiency than that of control [51] heavy metals on a solid surface and achieving stabilized state when the concentration of heavy metal is adsorbed. However, along with such positive sides, it also has some limitations like low efficiency and sorption capacities.…”