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As lithium intercalating complex metal oxides become more widely used in energy storage devices, there is an increasing need to understand their environmental impact at the end of their life cycle due to the lack of recycling options. In this study, we examine the biological impact of a panel of nanoscale lithium nickel manganese cobalt oxides (LixNiyMnzCo1−y−zO2, 0 < x, y, z < 1, abbreviated as NMCs), to a model Gram-positive bacterium, Bacillus subtilis in terms of cellular respiration and growth. A highly sensitive single-cell gel electrophoresis method is also applied for the first time to understand the genotoxicity of this nanomaterial to bacterial cells. Results from these assays indicate that the free Ni and Co ions released from the incongruent dissolution of the NMC material in B. subtilis growth media induced both hindered growth and cellular respiration. More remarkably, the DNA damage induced by the combination of the two ions in solution is comparble to that induced by the NMC material, which suggests the free Ni and Co ions are responsible for the toxicity observed. A material redesign by enriching Mn is also presented. The combined approaches of evaluating impact on bacterial growth, respiration, DNA damage at a single-cell level, as well as other phenotypical changes allows us to probe the nanomaterial and bacterial cells from a mechanistic prospective, and provides a useful means to an understanding of bacterial response to new potential environmental stressors.
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Nanoscale battery cathode materials induce DNA damage in bacteria
The increasing use of nanoscale lithium nickel manganese cobalt oxide (Li x Ni y Mn z Co 1−y−z O 2 , NMC) as a cathode material in lithium-ion batteries poses risk to the environment. Learning toxicity mechanisms on molecular levels is critical to promote proactive risk assessment of these complex nanomaterials and inform their sustainable development. We focused on DNA damage as a toxicity mechanism and profiled in depth chemical and biological changes linked to DNA damage in two environmentally relevant bacteria upon nano-NMC exposure. DNA damage occurred in both bacteria, characterized by double-strand breakage and increased levels of many putative chemical modifications on bacterial DNA bases related to direct oxidative stress and lipid peroxidation, measured by cutting-edge DNA adductomic techniques. Chemical probes indicated elevated intracellular reactive oxygen species and transition metal ions, in agreement with DNA adductomics and gene expression analysis. By integrating multi-dimensional datasets from chemical and biological measurements, we present rich mechanistic insights on nano-NMC-induced DNA damage in bacteria, providing targets for biomarkers in the risk assessment of reactive materials that may be extrapolated to other nano–bio interactions.
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- Award ID(s):
- 2001611
- PAR ID:
- 10198599
- Date Published:
- Journal Name:
- Chemical Science
- ISSN:
- 2041-6520
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/D0SC02987D
