Rhizosphere Microbial Communities and Geochemical Constraining Mechanism of Antimony Mine Waste-Adapted Plants in Southwestern China

Abstract

Antimony (Sb) and arsenic (As) are two hazardous metalloid elements, and the biogeochemical cycle of Sb and As can be better understood by studying plant rhizosphere microorganisms associated with Sb mine waste. In the current study, samples of three types of mine waste—Sb mine tailing, waste rocks, and smelting slag—and associated rhizosphere microorganisms of adapted plants were collected from Qinglong Sb mine, southwest China. 16S rRNA was sequenced and used to study the composition of the mine waste microbial community. The most abundant phylum in all samples was Proteobacteria, followed by Bacteroidota, Acidobacteriota, and Actinobacteriota. The community composition varied among different mine waste types. Gammaproteobacteria was the most abundant microorganism in tailings, Actinobacteria was mainly distributed in waste rock, and Saccharimonadia, Acidobacteriae, and Ktedonobacteria were mainly present in slag. At the family level, the vast majority of Hydrogenophilaceae were found in tailings, Ktedonobacteraceae, Chthoniobacteraceae, and Acidobacteriaceae (Subgroup 1) were mostly found in slag, and Pseudomonadaceae and Micrococcaceae were mainly found in waste rock. Actinobacteriota and Arthrobacter are important taxa for reducing heavy metal(loid) mobility, vegetation restoration, and self-sustaining ecosystem construction on antimony mine waste. The high concentrations of Sb and As reduce microbial diversity.

Legacy copper/nickel mine tailings potentially harbor novel iron/sulfur cycling microorganisms within highly variable communities

“…While Actinobacteriota are commonly found in mine tailings (especially metal tolerant Arthrobacter spp.) (Gao et al, 2021; Lopez et al, 2017; Xie et al, 2022), these organisms are usually obligate aerobes associated with the rhizosphere of metal hyper-accumulating plants. Therefore, we would expect to see them in the surface layers of vegetated tailings (e.g., ML34) as opposed to the deeper, ML25 tailings.…”

Legacy copper/nickel mine tailings potentially harbor novel iron/sulfur cycling microorganisms within highly variable communities

“…While members of the Actinobacteriota phylum display a diverse range of metabolism, the genera that are commonly found in mine tailings (especially metal tolerant Arthrobacter spp.) ( 42 – 44 ) are usually obligate aerobes associated with the rhizosphere of metal hyper-accumulating plants. Therefore, we would expect to see them in the surface layers of vegetated tailings (e.g., ML34) as opposed to the deeper, ML25 tailings.…”

Impact of Biochar Addition Levels on Remediation of Uranium-Stressed Soil: Evidence from 16S rDNA and Metabolomics

“…Based on previous research, Actinobacteriota mainly play two roles in uraniumcontaminated remediation systems: reducing uranium migration and providing bioactive substances by preying on certain microorganisms. 40,41 On the other hand, Myxococcota not only clear pathogens through predation but also enhance the degradation capabilities of functional bacteria toward pollutants. 42,43 In summary, when 1% biochar is added to the soil, it significantly increases the relative abundances of Actinobacteriota and Myxococcota, which may contribute to uranium immobilization and plant growth.…”