Metagenomic Analysis of Soil Microbial Community Shifts Formed by 60-Day Exposure to Polylactic Acid Microplastics
TL;DR
Functional predictions indicate that PLA processing drives functional remodeling of the microbial community to adapt to environmental stress by synergistically activating core energy metabolic pathways such as bacterial glycolysis and the tricarboxylic acid cycle.
Abstract
Soil microbial community dynamics are closely linked to ecosystem functions and responses to environmental stress. This study aimed to investigate the impacts of incubation time and different treatment conditions (CK, CK60, and PLA60) on soil bacterial community structure, diversity, and potential metabolic functions. A 60-day microcosm incubation experiment was conducted, comprising polylactic acid (PLA)-amended soil and blank controls. Metagenomic sequencing revealed that PLA exposure significantly altered both the structure and function of the soil microbial community. Over time, the Pseudomonadota phylum became significantly enriched, and the genus Sphingomonas emerged as the dominant genus. Alpha-diversity (Shannon index) decreased in PLA-treated soils, while beta-diversity (PCA) demonstrated distinct separation among treatment groups.Functional predictions indicate that PLA processing drives functional remodeling of the microbial community to adapt to environmental stress by synergistically activating core energy metabolic pathways such as bacterial glycolysis and the tricarboxylic acid cycle. The time effect and PLA treatment jointly drove the restructuring of the soil bacterial community.