Agroecología, El Colegio de la Frontera Sur, Unidad Campeche, Av Polígono s/n, Cd. Industrial, Lerma, Campeche, Mexico; Soil Physics and Land Management Group, Wageningen University & Research, Droevendaalsesteeg 4, 6708PB Wageningen, The Netherlands.
Soil Physics and Land Management Group, Wageningen University & Research, Droevendaalsesteeg 4, 6708PB Wageningen, The Netherlands.
Sci Total Environ. 2018 May 15;624:753-757. doi: 10.1016/j.scitotenv.2017.12.144. Epub 2017 Dec 27.
Low-density polyethylene (LDPE) is the most abundant source of microplastic pollution worldwide. A recent study found that LDPE decay was increased and the size of the plastic was decreased after passing through the gut of the earthworm Lumbricus terrestris (Oligochaeta). Here, we investigated the involvement of earthworm gut bacteria in the microplastic decay. The bacteria isolated from the earthworm's gut were Gram-positive, belonging to phylum Actinobacteria and Firmicutes. These bacteria were used in a short-term microcosm experiment performed with gamma-sterilized soil with or without LDPE microplastics (MP). We observed that the LDPE-MP particle size was significantly reduced in the presence of bacteria. In addition, the volatile profiles of the treatments were compared and clear differences were detected. Several volatile compounds such as octadecane, eicosane, docosane and tricosane were measured only in the treatments containing both bacteria and LDPE-MP, indicating that these long-chain alkanes are byproducts of bacterial LDPE-MP decay.
低密度聚乙烯（LDPE）是全球微塑料污染最丰富的来源。最近的一项研究发现，经过蚯蚓（Oligochaeta）肠道的传输后，LDPE 的降解速度加快，塑料的尺寸减小。在这里，我们研究了蚯蚓肠道细菌在微塑料降解中的作用。从蚯蚓肠道中分离出的细菌为革兰氏阳性菌，属于放线菌门和厚壁菌门。这些细菌被用于一个短期的微宇宙实验，在含有或不含有 LDPE 微塑料（MP）的γ-辐照土壤中进行。我们观察到，在有细菌存在的情况下，LDPE-MP 颗粒的尺寸明显减小。此外，还比较了处理的挥发性图谱，发现了明显的差异。仅在含有细菌和 LDPE-MP 的处理中测量到了几种挥发性化合物，如十八烷、二十烷、二十二烷和二十三烷，表明这些长链烷烃是细菌降解 LDPE-MP 的副产物。
