Biodegradation and disintegration of expanded polystyrene by land snails Achatina fulica.
Biodegradation and disintegration of expanded polystyrene by land snails Achatina fulica.
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DOI：
10.1016/j.scitotenv.2020.141289
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发表时间：
2020-07
期刊：
影响因子：
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通讯作者：
Yang Song;R. Qiu;Jiani Hu;Xinyu Li;Xiaoting Zhang;Yingxin Chen;Wei-Min Wu;Defu He
中科院分区：
文献类型：
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作者：
Yang Song;R. Qiu;Jiani Hu;Xinyu Li;Xiaoting Zhang;Yingxin Chen;Wei-Min Wu;Defu He
尽管越来越多的证据表明土壤中普遍存在塑料污染，但受土壤动物影响的塑料的命运在很大程度上仍然未知。在这项研究中，研究了膨化聚苯乙烯(PS)泡沫在全球分布的土壤无脊椎动物Achat inafulica中的摄取和生物降解能力。暴露4周后，每只钉螺摄入聚苯乙烯18.5±22.9 mg，粪便中排出微塑料(1.343±0.625 mm)，平均质量损失30.7%。凝胶渗透层析分析表明，粪便残留PS的重均相对分子质量(MW)和数均相对分子质量(Mn)显著增加，表明解聚程度有限。傅里叶变换红外光谱和质子核磁共振证实了氧化中间体官能团的形成。土霉素对肠道微生物的抑制作用不影响解聚，表明肠道微生物是独立存在的。高通量测序分析表明，摄入PS后肠道微生物群落发生了显著的变化，肠道细菌科、狮身菌科和气单胞菌科的数量增加，表明肠道微生物与PS的生物降解有关。这些发现表明，塑料垃圾可以分解成微塑料，并通过YA部分生物降解。这突出了土壤动物对塑料的命运及其在土壤环境中的生物降解的重要性。
Despite increasing evidence of widespread plastic pollution in soil, it remains largely unknown about the fate of plastic influenced by soil animals. In this study, ingestion and biodegradation capability of expanded polystyrene (PS) foam was investigated in a globally distributed soil invertebrate,Achatinafulica. After 4-week exposure, 18.5 ± 2.9 mg polystyrene was ingested per snail, and egested microplastics (1.343 ± 0.625 mm) in feces with significant mass loss of mean 30.7%. Gel permeation chromatography analysis indicated a significant increase in weight-average molecular weight (Mw) and number-average molecular weight (Mn) of feces-residual PS, indicating limited extent depolymerization. Fourier transform infrared spectroscopy and proton nuclear magnetic resonance confirmed the formation of functional groups of oxidized intermediates. Suppression of gut microbes with oxytetracycline did not affect the depolymerization, indicating the independence of gut microbes. High-throughput sequencing analysis revealed significant shifts in the gut microbiome after ingestion of PS, with an increase of familyEnterobacteriaceae,Sphingobacteriaceae, andAeromonadaceae, suggesting that gut microorganisms were associated with PS biodegradation. These findings suggest that plastic litter can be disintegrated into microplastics and partially biodegraded byA. fulica, which highlights the significance of soil animals for the fate of plastic and its biodegradation in soil environments.