研究課題/領域番号 |
19K20435
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研究機関 | 島根大学 |
研究代表者 |
長門 豪 島根大学, 学術研究院環境システム科学系, 助教 (50793832)
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研究期間 (年度) |
2019-04-01 – 2023-03-31
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キーワード | microplastics / nanoplastics / Raman spectrometry / plastic degradation / ATR-FTIR |
研究実績の概要 |
Winowgradsky columns have been made with plastic surfaces contained within and have been in incubation for the DNA analysis of the microbial corona that forms on plastic surfaces at differing stages of degradation. These were made an incubated with local microbes and organic matter. Initial tests on environmental DNA have been performed and will continue as a counterpoint to the laboratory studies into the current year. Studies on the structure of plastics in the environment have continued as well, particularly in beached samples, providing a context for how actual environmental plastics are degraded. This will in turn affect how microbial colonies are formed. This has been investigated using Raman and ATR-FT-IR as the main analytical modalities. Confirmation of previous results of the presence and formation of hydroxylated PAH congeners were also validated using LC-MS/MS and their formation from the action of microbes has been confirmed and the results are currently being written for publication. Initial range finding tests for the study examining nanoplastic interactions with microbes (i.e. finding appropriate nanoplastic and organic matter concentrations) started this year, using yeast as a model organism.
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現在までの達成度 (区分) |
現在までの達成度 (区分)
3: やや遅れている
理由
Issues this year were primarily based on the procurement of materials due to supply chain issues. As a result, the DNA Qubit analyzer took time to arrive and the appropriate Qiagen kits were also not available for a period. These are supplies to be used in the ecocorona experiments. This caused delays that extended beyond the summer, where environmental samples are primarily taken.
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今後の研究の推進方策 |
The final component of the project will begin with DNA genome sequencing of ecocoronas growing on plastics, both in the laboratory (from Winogradsky columns) and in comparison to ecocoronas found on environmental plastics. Nanoplastic experiments with microbes are underway using normal and functionalized polystyrene nanoparticles using Raman imaging as a way to monitor the interaction of microplastics and the microplastics-DOM corona complex with microbial cells. Baseline information will come from dynamic light scattering and zeta-potential measurements. However, the inclusion of Raman imaging will allow not only the monitoring of where nanoplastics interactions with cells, but also how certain biochemical constituents are modified in the process. PAHs will be incorporated to see if there is a protective effect and to understand the extent to which the hydroxylated congeners are forming and will constitute the final component of the study.
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次年度使用額が生じた理由 |
The remaining funds will be used primarily for DNA analyses and for the studies of the nanoplastic corona formation experiments. The costs will mostly be in the DNA sequencing that will be performed by an outside provider and the per sample costs have already been negotiated. A small amount will also be used in glassware for the Raman imaging of the ecocorona formation.
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