Effects of four endophytic bacteria on cadmium speciation and remediation efficiency of Sedum plumbizincicola in farmland soil

• Published in: Environmental science and pollution research international 2022-12, Vol.29 (59), p.89557-89569
• Main Authors: Cheng, Xueyu, Cao, Xueying, Tan, Changyin, Liu, Lulu, Bai, Jia, Liang, Yufeng, Cai, Runzhong
• Format: Article
• Language: English
• Subjects: Agricultural land; Agricultural pollution; Agricultural production; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bacteria; Bioaccumulation; Biological magnification; Cadmium; Continuous cropping; Earth and Environmental Science; Ecotoxicology; Efficiency; Endophytes; Environment; Environmental Chemistry; Environmental Health; Environmental science; Inoculation; Phytoremediation; Research Article; Sedum plumbizincicola; Shoots; Soil bacteria; Soil chemistry; Soil conditions; Soil contamination; Soil microorganisms; Soil pH; Soil pollution; Soil remediation; Soils; Speciation; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-022-21711-y

Cadmium (Cd) pollution in farmland soils severely affects agricultural production safety, thereby threatening human health. Sedum plumbizincicola is a Cd and Zn hyperaccumulator commonly used for the phytoremediation of Cd-contaminated soil. This study was aimed to improve the remediation effect of S. plumbizincicola on Cd-contaminated farmland soil and provide a theoretical basis for the enhancement of endophytic bacteria in the repair of Cd-contaminated soil with S. plumbizincicola. Four kinds of endophytic bacteria, namely Buttiauxella , Pedobacter , Aeromonas eucrenophila , and Ralstonia pickettii , were used, and soil culture experiments and pot experiments were conducted to explore the effects of endophytic bacteria on soil Cd speciation and phytoremediation efficiency of Cd-contaminated farmland soils. Under the experimental conditions, after inoculation with endophytic bacteria, the soil pH was effectively reduced, content of weak acid-extracted Cd and oxidizable Cd increased, and content of reducible Cd and residual Cd decreased. Soil Cd activity was increased, and the availability coefficient of soil Cd increased by 1.15 to 6.41 units compared with that of the control (CK 2 ). Compared with CK 2 , the biomass of S. plumbizincicola significantly increased by 23.23–55.12%; Cd content in shoots and roots of S. plumbizincicola increased by 29.63–46.01% and 11.42–84.47%, respectively; and bioconcentration factor was 2.13 to 2.72 times that of CK 2 . The Cd removal rate of S. plumbizincicola monocropping was 48.25%. When S. plumbizincicola was planted with inoculating endophytic bacteria, the Cd removal rate in the soil reached 61.18–71.49%, which was significantly higher than that of CK 2 ( p