Microplastics drive the reconfiguration of microbial sulfur cycling pathways in seagrass bed sediments

作者：Mingguang Luo, Jinluo Fan, Xiujun Wang, Yibing Ge, Dan Feng, Shengkai Cao, Jun Wang, Hui Deng, Jiwei Luo, Yuanyuan Zhao, C. Ge, Honglin Bu · 发表于：Environmental Pollution · 年份：2026 · DOI：10.1016/j.envpol.2026.128089 · 被引用次数：2 · 研究领域：Microplastics and Plastic Pollution、Marine Biology and Environmental Chemistry、Calcium Carbonate Crystallization and Inhibition

Microplastics (MPs) pollution threatens marine biogeochemical cycles, but its impact on the sediment sulfur cycle remains unclear. A 112-day microcosm incubation experiment was conducted to investigate the effects of three common MPs, polylactic acid (PLA), polyethylene (PE), and polystyrene (PS), on sulfur speciation, microbial communities, and functional genes in seagrass bed sediments using integrated amplicon sequencing and metagenomics. MPs significantly altered sediment sulfur speciation, with PLA inducing the strongest shifts, including 111.2% accumulation of total inorganic sulfate (TIS) and a 163.3% increase in TIS/Sulfide ratios, indicative of enhanced sulfur oxidation, while PE and PS promoted sustained sulfide accumulation. Distinct polymer-specific changes in sulfur-cycling bacteria communities were observed, with PLA suppressing the dominant Bradymonas (31.3% decrease) while enriching heterotrophic Sulfitobacter (26.5% increase), PE driving a transition towards autotrophic pathways with Thiohalomonas increasing by 272.8%, and PS selectively enriching generalist sulfur-oxidizing genera such as Roseovarius and Methyloceanibacter. Metagenomic analysis highlighted a shift from assimilatory biosynthetic pathways to dissimilatory energy-generating processes. These findings suggest that MPs intensify sulfide stress and disrupt sulfur metabolism, thereby reducing sediment biogeochemical stability and potentially impairing carbon burial and ecosystem resilience. These re...