Bacterial endophytes enhance phytostabilization in soils contaminated with uranium and lead

Abstract

The combined use of plants and bacteria is a promising approach for the remediation of polluted soil. In the current study, the potential of bacterial endophytes in partnership with Leptochloa fusca (L.) Kunth was evaluated for the remediation of uranium (U)- and lead (Pb)-contaminated soil. L. fusca was vegetated in contaminated soil and inoculated with three different endophytic bacterial strains, Pantoea stewartii ASI11, Enterobacter sp. HU38, and Microbacterium arborescens HU33, individually as well as in combination. The results showed that the L. fusca can grow in the contaminated soil. Bacterial inoculation improved plant growth and phytoremediation capacity: this manifested in the form of a 22-51% increase in root length, 25-62% increase in shoot height, 10-21% increase in chlorophyll content, and 17-59% more plant biomass in U- and Pb-contaminated soils as compared to plants without bacterial inoculation. Although L. fusca plants showed potential to accumulate U and Pb in their root and shoot on their own, bacterial consortia further enhanced metal uptake capacity by 53-88% for U and 58-97% for Pb. Our results indicate that the combination of L. fusca and endophytic bacterial consortia can effectively be used for the phytostabilization of both U- and Pb-contaminated soils.

Phytoremediation: a sustainable environmental technology for heavy metals decontamination

“…On the basis of metal concentration in their tissues, plant species can be divided into 3 groups [1] HM accumulator species, [2] HM indicator species and [3] HM excluder species [14]. The accumulator species; plants are able to uptake very high contents of HMs (in shoots or roots) exceeding the levels in the soil.…”

“…Plants suitable for phytoremediation have four important characteristics: [1] rapid growth and high biomass [2] profound root system, [3] easily harvestable and [4] accumulation of high levels of HMs in shoots. Hyper-accumulator plants are generally relatively rare in the nature and are widespread in contaminated soils, signifying that hyper-accumulation is an important eco-physiological trait to HMs resistance and one of the indicators of toxin adaptation [111].…”

Floating Wetlands: A Sustainable Tool for Wastewater Treatment

“…In a study conducted in Singapore, above ground tissue of Chrysopogon zizanioides and T. angustifolia were repeatedly harvested within a year and analyzed. Phosphorus and nitrogen contents in the shoots tissues were decreased when shoots acquired maturity . Therefore, it was recommended that shoots should be harvested before the culmination of growing season to achieve the maximum removal of nutrients.…”

Phytoremediation of Heavy Metal Pollution: A Bibliometric and Scientometric Analysis from 1989 to 2018

“…Enhanced HM phytoremediation technology has been a hot topic in this field. These technologies include the use of exogenous substances (e.g., organic additives, inorganic additives, fertilizers, auxin applications, exogenous inoculation of bacteria, and microorganisms) [111,112,113,114]. Recently, more attention has been paid to the effects of bacteria/microorganisms on the uptake of HMs in plants [115,116,117].…”