重金属胁迫驱动微塑料表面菌群演替及其吸附特性变化分析OA

Both microplastics and heavy metal co-pollution are widely recognized as critical environmental concerns in marine ecosystems.Polyethylene terephthalate(PET),a typical microplastic in marine environments,was used as the study substrate.In-laboratory simulated heavy metal exposure experiments were conducted,combined with high-throughput sequencing and adsorption capacity analysis,to reveal the regulatory role of heavy metal stress on the structural composition of microplastic surface microbial communities,and to further investigate the impact of biofilms on heavy metal loading by microplastics.The results showed that heavy metal stress induced a low-abundance,high-uniformity profile in microplastic surface microbial communities.Differences in heavy metal stress mechanisms shaped unique microbial taxa on microplastic surfaces,driving adaptive succession in community structure,and led to increased abundance of heavy metal-tolerant groups such as the phylum Actinobacteriota.Across different treatment groups,5-9 unique microbial marker taxa were identified,with most dominant taxa belonging to the phyla Proteobacteria and Bacteroidetes,which maintained community stability through synergistic or competitive interactions.Biofilms enhanced heavy metal adsorption on microplastic surfaces by 1.21-fold to 3.47-fold by altering the physicochemical properties of the microplastic surface,while heavy metal type emerged as a key environmental factor influencing microbial community differentiation on microplastics.These findings elucidated the coupled interaction mechanism of microplastic-biofilm-heavy metal composite pollution and provided a critical theoretical basis for microbial-mediated remediation technologies targeting composite pollution.