A newly isolated bacterium Comamonas sp. XL8 alleviates the toxicity of cadmium exposure in rice seedlings by accumulating cadmium

Zunji Shi; Xiaoli Qi; Xin-An Zeng; Yujing Lu; Jinlin Zhou; Kehui Cui; Limin Zhang

doi:10.1016/j.jhazmat.2020.123824

A newly isolated bacterium Comamonas sp. XL8 alleviates the toxicity of cadmium exposure in rice seedlings by accumulating cadmium

J Hazard Mater. 2021 Feb 5:403:123824. doi: 10.1016/j.jhazmat.2020.123824. Epub 2020 Sep 3.

Authors

Zunji Shi¹, Xiaoli Qi², Xin-An Zeng³, Yujing Lu⁴, Jinlin Zhou⁵, Kehui Cui⁶, Limin Zhang⁷

Affiliations

¹ Chinese Academy of Sciences (CAS) Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Centre for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, CAS, Wuhan 430071, China; School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China.
² National Key Laboratory of Crop Genetic Improvement, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
³ School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China.
⁴ School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou 510006, China; Engineering Research Academy of High Value Utilization of Green Plants, Meizhou, 514021, China.
⁵ Engineering Research Academy of High Value Utilization of Green Plants, Meizhou, 514021, China.
⁶ National Key Laboratory of Crop Genetic Improvement, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China. Electronic address: cuikehui@mail.hzau.edu.cn.
⁷ Chinese Academy of Sciences (CAS) Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Centre for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, CAS, Wuhan 430071, China; Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430079, China. Electronic address: zhanglm@wipm.ac.cn.

PMID: 33264916
DOI: 10.1016/j.jhazmat.2020.123824

Abstract

Cadmium (Cd) is a typical heavy-metal highly accumulating in crops and drinking water, thus posing a severe health risk for human health. In this study, we firstly isolated 24 Cd-resistant bacteria from the heavy-metals contaminated soil at Daye Iron Ore, in which Comamonas sp. XL8 exhibited a high resistance and strong accumulation capacity to Cd. After absorption, Comamonas sp. XL8 could biosynthesize intracellular Cd-nanoparticles (CdNPs), which has not been reported in characteristics of Comamonas genus before. We found that the gene expressions of cadA and bmtA related to Cd transportation and binding in strain XL8 were significantly upregulated with Cd exposure, suggesting that genes cadA and bmtA may contribute to the formation of CdNPs. Of particular note, the co-inoculation of Comamonas sp. XL8 and rice seedlings (Oryzae sativa L.) significantly decreased the oxidative stress-induced by Cd accumulation and subsequently alleviated toxicity of Cd exposure. Our results reveal the biochemical process of Cd accumulation in Comamonas sp. XL8 by forming CdNPs, showing that it has great potential for effective bioremediation of environmental Cd exposure.

Keywords: Bioremediation; Cadmium-resistant bacteria; Co-inoculation; Comamonas; Nanoparticles.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bacteria
Biodegradation, Environmental
Cadmium / analysis
Cadmium / toxicity
Comamonas*
Humans
Oryza*
Seedlings
Soil
Soil Pollutants* / analysis
Soil Pollutants* / toxicity

Substances

Soil
Soil Pollutants
Cadmium