Traditional microplastics alter microbial community, metabolites and nutrition in heavy metal-contaminated coastal saline soil

Abstract Microplastics and various other contaminants are frequently present in soil. Here we investigated the long-term integrated responses of changes in the microbial community, metabolomics, heavy metal availability, and nutritional properties of the cadmium-cuprum-zinc-contaminated coastal saline soil to the three different microplastics. Various categories of microplastics had notable impacts on the available potassium, organic matter, availability of cadmium and cuprum, as well as the enzymatic activity in soil. Microplastics contamination caused diverse changes in microbial diversity and the composition of bacterial and fungal communities, resulting in the enrichment of Mortierella and a decrease of Bacillus abundance. The metabolites in soil primarily affected by microplastics contamination were the pathways involved organic acids and their derivatives, organoheterocyclic compounds, as well as lipids and lipid-like substances. Therefore, the addition of microplastics to soil may influence soil fertility, metal mobility, and alter the structure and metabolic processes of the microbial community in soil.