Li Yuting, Gu Peng, Zhang Wen, Sun Hongwen, Wang Jianing, Wang Leilei, Li Bing, Wang Lei
Shandong Provincial Key Laboratory of Applied Microbiology, Ecology Institute of Shandong Academy of Sciences, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250103, China.
Shandong Provincial Key Laboratory of Applied Microbiology, Ecology Institute of Shandong Academy of Sciences, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250103, China.
J Hazard Mater. 2023 May 5;449:131001. doi: 10.1016/j.jhazmat.2023.131001. Epub 2023 Feb 13.
Anthropogenic activities such as in situ straw incineration and the widespread use of agricultural film led to the accumulation of polycyclic aromatic hydrocarbons (PAHs) and microplastics (MPs) in agricultural soils. In this study, four biodegradable MPs (BPs), including polylactic acid (PLA), polybutylene succinate (PBS), poly-β-hydroxybutyric acid (PHB) and poly (butylene adipate-co-terephthalate) (PBAT) and non-biodegradable low-density polyethylene (LDPE) were selected as representative MPs. The soil microcosm incubation experiment was conducted to analyze MPs effects on PAHs decay. MPs did not influence PAHs decay significantly on day 15 but showed different effects on day 30. BPs reduced PAHs decay rate from 82.4% to 75.0%- 80.2% with the order of PLA < PHB < PBS < PBAT while LDPE increased it to 87.2%. MPs altered beta diversity and impacted the functions to different extents, interfering in PAHs biodegradation. The abundance of most PAHs-degrading genes was increased by LDPE and decreased by BPs. Meanwhile, PAHs speciation was influenced with bioavailable fraction elevated by LDPE, PLA and PBAT. The facilitating effect of LDPE on 30-d PAHs decay can be attributed to the enhancement of PAHs-degrading genes and PAHs bioavailability, while the inhibitory effects of BPs were mainly due to the response of the soil bacterial community.
诸如就地焚烧秸秆和广泛使用农用薄膜等人为活动导致了农业土壤中多环芳烃（PAHs）和微塑料（MPs）的积累。在本研究中，选择了四种可生物降解的微塑料（BPs），包括聚乳酸（PLA）、聚丁二酸丁二醇酯（PBS）、聚-β-羟基丁酸（PHB）和聚己二酸/对苯二甲酸丁二醇酯（PBAT）以及不可生物降解的低密度聚乙烯（LDPE）作为代表性微塑料。进行了土壤微观培养实验以分析微塑料对多环芳烃降解的影响。在第15天，微塑料对多环芳烃的降解没有显著影响，但在第30天显示出不同的效果。可生物降解微塑料使多环芳烃的降解率从82.4%降至75.0% - 80.2%，顺序为PLA < PHB < PBS < PBAT，而低密度聚乙烯则将其提高到87.2%。微塑料改变了β多样性并在不同程度上影响了功能，干扰了多环芳烃的生物降解。大多数多环芳烃降解基因的丰度因低密度聚乙烯而增加，因可生物降解微塑料而降低。同时，多环芳烃的形态受到影响，低密度聚乙烯、聚乳酸和聚己二酸/对苯二甲酸丁二醇酯使生物可利用部分升高。低密度聚乙烯对30天多环芳烃降解的促进作用可归因于多环芳烃降解基因的增强和多环芳烃的生物可利用性，而可生物降解微塑料的抑制作用主要归因于土壤细菌群落的反应。
