College of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, China.
Macao Environmental Research Institute, Macau University of Science and Technology, Macau, China.
Environ Sci Pollut Res Int. 2023 Apr;30(19):55649-55661. doi: 10.1007/s11356-023-26159-2. Epub 2023 Mar 10.
The stress produced from biodegradable plastics on soil ecosystem is a rising global concern. However, effects of such microplastics (MPs) on soil ecology are still debatable. In this study, the biodegradable microplastic PBAT (polyadipate/butylene terephthalate) was used as the target object, compared with the traditional microplastic LDPE (low-density polyethylene). A pot experiment and was high-throughput sequencing analysis used to determine the effect of different additions of MPs on soil bacterial community structure and the correlation between soil bacterial community structure and chemical properties was investigated. Compared with LDPE, the results showed that EC, TN, TP, NH-N, and NO-N changed obviously with the increasing of PBAT addition (p < 0.05), but pH changed little and the community richness was significantly higher in soils with low PBAT addition than that with higher PBAT addition. PBAT is beneficial to soil nitrogen fixation, but it will significantly reduce the soil P content and affect the nitrification and denitrification reaction. It suggested that addition of PBAT MPs and its addition amount result in changes in soil fertility, community abundance, and structure and composition of bacterial communities in soil samples, while the presence of PBAT MPs might affect soil carbon-nitrogen cycle.
可生物降解塑料给土壤生态系统带来的压力是一个日益引起全球关注的问题。然而，此类微塑料（MPs）对土壤生态的影响仍存在争议。在本研究中，以生物降解性微塑料 PBAT（聚己二酸/对苯二甲酸丁二醇酯）为目标物，与传统微塑料 LDPE（低密度聚乙烯）进行了对比。采用盆栽实验和高通量测序分析，确定了 MPs 不同添加量对土壤细菌群落结构的影响，并研究了土壤细菌群落结构与化学性质之间的相关性。结果表明，与 LDPE 相比，随着 PBAT 添加量的增加，EC、TN、TP、NH-N 和 NO-N 明显变化（p < 0.05），但 pH 变化不大，低 PBAT 添加量土壤的群落丰富度明显高于高 PBAT 添加量土壤。PBAT 有利于土壤固氮，但会显著降低土壤 P 含量，并影响硝化和反硝化反应。这表明 PBAT MPs 的添加及其添加量会导致土壤肥力、土壤样本中细菌群落的丰度、结构和组成发生变化，而 PBAT MPs 的存在可能会影响土壤碳氮循环。
