Shanxi Key Laboratory for Ecological Restoration of Loess Plateau China, Observation and Research Station of the Ministry of Education of Shanxi Subalpine Grassland Ecosystem, Institute of Loess Plateau, Shanxi University, Taiyuan 030006, China.
Canadian Light Source Inc., University of Saskatchewan, Saskatoon, SK S7N 2V3, Canada.
J Hazard Mater. 2024 Apr 5;467:133726. doi: 10.1016/j.jhazmat.2024.133726. Epub 2024 Feb 8.
Understanding of the environmental behaviors of microplastics is limited by a lack of knowledge about how photoaging influences biofilm formation on microplastics in soil. Here, original microplastics (OMPs) and photoaged-microplastics (AMPs) were incubated in soil to study the effect of photoaging on formation and characteristics of biofilm on the poly (butylene succinate) microplastics. Because photoaging decreased the hydrophobicity of the microplastic, the biomass of biofilm on the OMPs was nearly twice that on the AMPs in the early stage of incubation. However, the significance of the substrate on biomass in the biofilm declined as the plastisphere developed. The bacterial communities in the plastisphere were distinct from, and less diverse than, those in surrounding soil. The dominant genera in the OMPs and AMPs plastispheres were Achromobacter and Burkholderia, respectively, indicating that photoaging changed the composition of the bacterial community of biofilm at the genus level. Meantime, photoaging decreased the complexity and stability of the plastisphere bacterial community network. Results of Biolog ECO-microplate assays and functional prediction from amplicons showed that photoaging treatment enhanced the carbon metabolic capacity of the microplastic biofilm. This study provides new insights into the formation of plastispheres in soil.
由于光老化降低了微塑料的疏水性，在培养初期，OMPs 上生物膜的生物量几乎是 AMPs 的两倍。然而，随着生物膜的发展，基质对生物膜生物量的影响变得不那么显著。生物膜的细菌群落与周围土壤中的细菌群落不同，多样性也较低。在 OMPs 和 AMPs 的生物膜中，优势属分别为无色杆菌属（Achromobacter）和伯克氏菌属（Burkholderia），这表明光老化改变了生物膜细菌群落的组成在属水平上。同时，光老化降低了生物膜塑料球细菌群落网络的复杂性和稳定性。Biolog ECO 微平板分析和扩增子功能预测的结果表明，光老化处理增强了微塑料生物膜的碳代谢能力。这项研究为土壤中生物膜的形成提供了新的见解。
