1. Academic Validation
  2. Probing the single and combined toxicity of PFOS and Cr(VI) to soil bacteria and the interaction mechanisms

Probing the single and combined toxicity of PFOS and Cr(VI) to soil bacteria and the interaction mechanisms

  • Chemosphere. 2020 Jun;249:126039. doi: 10.1016/j.chemosphere.2020.126039.
Jie Li 1 Tongtong Zheng 1 Dong Yuan 2 Canzhu Gao 1 Chunguang Liu 3
Affiliations

Affiliations

  • 1 School of Environmental Science and Engineering, Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, China-America CRC for Environment & Health of Shandong Province, Shandong University, 72# Jimo Binhai Road, Qingdao, Shandong, 266237, PR China.
  • 2 Department of Chemistry and Chemical Engineering, Qilu Normal University, Shandong Province, 36# Lishan Road, Jinan, 250013, PR China.
  • 3 School of Environmental Science and Engineering, Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, China-America CRC for Environment & Health of Shandong Province, Shandong University, 72# Jimo Binhai Road, Qingdao, Shandong, 266237, PR China; Guangzhou Key Laboratory of Environmental Exposure and Health, School of Environment, Jinan University, PR China. Electronic address: chunguangliu2013@sdu.edu.cn.
Abstract

Many research focused on the removal of perfluorooctane sulfonic acid (PFOS) and hexavalent chromium (Cr(VI)) in some industrial wastewater (e.g. electroplating wastewater), but few research reported the combined toxicity of PFOS and Cr(VI) to soil bacteria. Therefore, the toxicity and mechanisms of the combined PFOS and Cr(VI) to bacteria (with Bacillus subtilis as a model) are explored. The results show that the combined PFOS and Cr(VI) exhibits much higher toxicity to the bacteria than that of Cr(VI) alone. The growth profile of Bacillus subtilis exposed by the combined pollution decreased by 18% and 56%, respectively, compared with that of single Cr(VI) and the control, indicating the combined toxicity to Bacillus subtilis is synergistic. Moreover, the changes of EPSs in Bacillus subtilis, such as decreased potential, increased extracellular Polysaccharides, decreased extracellular proteins and irregular morphology, also confirmed that the combined PFOS and Cr(VI) caused greater toxicity. The increase of intracellular ROS and permeability of dye 4', 6-diamidino-2-phenylindoledihydrochloride (DAPI) suggest that oxidative damage and increased membrane permeability are the main mechanisms of toxicity induced by the combined PFOS and Cr(VI). This work could provide useful information for the risk assessment of co-exposure to PFOS and heavy metals in the natural environment.

Keywords

Combined toxicity; Heavy metals; Microbial ecotoxicology; POPs; Soil bacteria.

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