不同官能团微塑料对斑马鱼胚胎菌群和代谢功能的胁迫效应

为探究官能团修饰对微塑料生物效应的影响规律和机制，分析了3种聚苯乙烯微塑料（PS、PS—NH₂和PS—COOH）在斑马鱼（Danio rerio）胚胎内的累积特征，并利用微生物组学和代谢组学相结合的分析技术，解析了斑马鱼幼鱼体内代谢功能及微生物群落的响应规律.结果显示，3种微塑料都可以在斑马鱼体内产生累积，其含量范围为143~175 μg·g^-1，且不存在明显差异性.斑马鱼胚胎绒毛膜是微塑料早期暴露的主要累积场所，但不能有效阻止小粒径微塑料的穿透.未修饰的PS明显影响了斑马鱼幼鱼体内氨基糖苷类的代谢能力，PS—NH₂主要对氨基酸的代谢过程产生了影响，而PS—COOH则主要作用于三羧酸循环、氨基酸及糖酵解等代谢通路.3种微塑料均导致了斑马鱼幼鱼体内代谢功能的变化，从而对斑马鱼产生了毒性效应，而微塑料的官能团修饰则加强了这一影响程度.与对照组相比，PS—NH₂明显降低了斑马鱼幼鱼体内的微生物群落的多样性，显著增加了变形菌门（Proteobacteria）的占比，导致斑马鱼幼鱼体内的菌群失衡，从而引起鱼体代谢功能的紊乱.微塑料的官能团修饰可能会明显改变其对生物体的胁迫效应，导致难以预测的生态风险.

Biological Effect of Microplastics with Different Functional Groups on the Bacterial Communities and Metabolic Functions of Zebrafish (Danio rerio) Embryos

To investigate the influences of functional groups on the biological effects caused by microplastics, the accumulation of three polystyrene microplastics (PS, PS-NH₂, and PS-COOH) in zebrafish (Danio rerio) embryos were analyzed, and then the responses of metabolic functions and microbial communities in zebrafish larvae were revealed using the combination of the microbiome and metabolome methods. The results showed that all microplastics could accumulate in zebrafish with concentrations ranging from 143 to 175 μg·g^-1, and there were no significant differences in the accumulation potentials among different PS treatments. Exposure to plain PS significantly affected the metabolic capacity of aminoglycosides in zebrafish larvae, whereas the metabolic processes of amino acids were affected by PS-NH₂. In the PS-COOH treatment, the metabolic pathways of the tricarboxylic acid cycle, amino acids, and glycolysis in zebrafish were markedly altered. The metabolic functions of zebrafish larvae were changed by all PS microplastics, resulting in toxic effects on zebrafish, and the functional group modification of microplastics may have further enhanced these toxicities. Compared to that in the control, exposure to PS-NH₂ significantly reduced the diversity of microbial communities in zebrafish larvae and increased the proportion of Proteobacteria in the composition, leading to an imbalance of the bacterial community in zebrafish and thus disrupting the metabolic functions in the fish. Therefore, the functional modifications of microplastics may significantly alter the related stresses on aquatic organisms, leading to unpredictable ecological risks.