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Abstract：
Yellow mealworms (Tenebrio molitor larvae) are capable of biodegrading polystyrene (PS) and low-density polyethylene (LDPE). This study tested biodegradation of one expanded PS (EPS) with a weight-average molecular weight (Mw) 256.4 kDa and two LDPE foams with respective Mw of 130.6 kDa (PE-1) and 288.7 kDa (PE-2) in T. monitor larvae obtained in Beijing, China. The larvae consumed EPS and both LDPEs over a 60 day. Fourier transform infrared spectroscopy and thermogravimetric analyses of frass confirmed the formation of new oxygen-containing functional groups, as well as a change in physical property and chemical modification, indicating that biodegradation of EPS and LDPE occurred. Gel permeation chromatography analysis confirmed broad depolymerization of EPS and PE-1 (i.e., a decrease in both Mw and a number-average molecular weight (Mn)) but revealed limited extent depolymerization of PE-2 (i.e., increase in Mn and decrease in Mw). For all materials, the size-average molecular weight (Mz) was decreased. Biodegradation and oxidation of EPS and LDPE were confirmed using FTIR and TGA analysis. Depression of gut microbes by the antibiotic gentamicin resulted in significant inhibition of EPS depolymerization but did not stop LDPE depolymerization, resulting in the increase in Mn and revealing that PS biodegradation was gut microbe-dependent but LDPE biodegradation was less dependent or independent of gut microbes. Gut microbial community analysis indicated that, as expected, under different dietary conditions, the intestinal flora significantly shifted to communities associated with biodegradation of EPS and LDPE. The results indicated the complexity and limitation of biodegradation of plastics in plastics-eating T. molitor larvae.
摘要：
黄粉虫（黄粉虫幼虫）能够生物降解聚苯乙烯（PS）和低密度聚乙烯（LDPE）。这项研究测试了一种重均分子量（Mw）为256.4kDa的膨胀PS（EPS）和两种Mw分别为130.6kDa（PE-1）和288.7kDa（PE-2）的LDPE泡沫在T中的生物降解。北京获得的监测幼虫，中国。幼虫在60天内消耗EPS和两种LDPE。傅里叶变换红外光谱和热重分析证实了新的含氧官能团的形成，以及物理性质和化学修饰的变化，表明EPS和LDPE发生了生物降解。凝胶渗透色谱分析证实了EPS和PE-1的广泛解聚(即，Mw和数均分子量（Mn）均降低），但表明PE-2的解聚程度有限（即，Mn的增加和Mw的减少)。对于所有材料，尺寸平均分子量(Mz)降低。使用FTIR和TGA分析证实了EPS和LDPE的生物降解和氧化。抗生素庆大霉素对肠道微生物的抑制作用显著抑制了EPS的解聚，但并未阻止LDPE的解聚。导致Mn的增加，并表明PS的生物降解是肠道微生物依赖性的，而LDPE的生物降解对肠道微生物的依赖性或独立性较小。肠道微生物群落分析表明,正如预期的那样，在不同的饮食条件下，肠道菌群显著向与EPS和LDPE生物降解相关的群落转移。结果表明，以塑料为食的墨虫幼虫中塑料生物降解的复杂性和局限性。
