The Impact of Inoculation of Two Strains of Rhizobacteria on Radionuclide Transfer in Sesbania Grandiflora

Abstract

Transfer factors of some naturally-occurring and artificial radionuclides from an agricultural soil to rhizobacteria-treated Sesbania grandiflora, a small leguminous tree, were studied. Two plant growth promoting rhizobacteria (PGPR) strains (SCR17 and PCE2) were used to carry out an agricultural experiment in pots in semi-arid region (Syria). The results showed the bacterial strain (SCR17) increased the transfer and accumulation of ²³⁸U and ⁴⁰K in Sesbania grandiflora, while both bacterial strains showed no effect on the accumulation of ²³⁴Th, ²²⁶Ra, ²¹⁰Po and ²¹⁰Pb in the treated plants. The transfer factor of ¹³⁷Cs from soil to rhizobacteria-treated Sesbania grandiflora was negligible. The values of the transfer factors of ²³⁴Th, ²²⁶Ra, ²¹⁰Po and ⁴⁰K were found to be within the global values, while the values of the transfer factors of ²³⁸U and ²¹⁰Pb were found to be relatively higher. This study highlights the importance of using Phytoremediation by PGPR strains for radionuclides-contaminated soils. Therefore, this method is a promising technique for the restoration and rehabilitation of contaminated sites with radionuclides, as it is low cost, easy to apply, and environmentally friendly.