聚苯乙烯纳米塑料（PS-NPs）和Cu2+在废水中共存可产生复合胁迫效应。采用PS-NPs和Cu2+对好氧反硝化菌（Pseudomonas stutzeri）进行胁迫，考察了菌株的生长、脱氮以及生化特性，通过转录组学阐明了胁迫机制。研究表明，50 mg/L PS-NPs胁迫下，菌株生长活性与对照相比提升了25.3%，脱氮活性提高，有关核糖体、TCA循环及ABC转运通路显著上调。10 mg/L Cu2+胁迫下，菌株生长活性与对照相比下降了83.2%，菌株受到显著抑制，细胞膜破损，有关核糖体、氮代谢及ABC转运通路代谢途径显著下调，与胞外聚合物（EPS）分泌、细胞膜合成有关基因丰度显著上调。复合胁迫下，Cu2+胁迫占据主导地位，但PS-NPs会刺激更多EPS产生，PS-NPs和EPS可以吸附部分Cu2+，减缓Cu2+对菌株的损伤。研究结果可为好氧反硝化菌处理纳米塑料和重金属废水提供理论支持。

Polystyrene nanoplastics (PS-NPs) and Cu2+ coexistence in wastewater can induce a compound stress effect. The growth, nitrogen removal, and biochemical characteristics of aerobic denitrifying bacteria (Pseudomonas stutzeri) were investigated under PS-NPs and Cu2+ stress conditions, while the stress mechanism was elucidated through transcriptomics analysis. The results showed that under the stress of 50 mg/L PS-NPs, the bacteria exhibited an 25.3% increase in growth activity compared to the control group, accompanied by enhanced nitrogen removal activity and significant upregulation of ribosome, TCA cycle, and ABC transport pathway. Under the stress of 10 mg/L Cu2+, the growth activity of the bacteria decreased by 83.2% compared to the control, and the bacteria was significantly inhibited. The cell membrane was damaged, and the metabolic pathways related to ribosome, nitrogen metabolism, and ABC transport were significantly downregulated. The genes related to extracellular polymeric substances (EPS) secretion, cell membrane synthesis were significantly upregulated. Under compound stress conditions, Cu2+ stress exerted dominant effects. However, PS-NPs exhibited the ability to stimulate enhanced EPS production. Additionally, both PS-NPs and EPS demonstrated the capacity to adsorb a portion of Cu2+, thereby alleviating the detrimental effects caused by Cu2+ on the bacteria. These results provide theoretical insights into utilizing aerobic denitrifying bacteria for treating nanoplastics and heavy metal wastewater.

中国博士后科学基金,国家自然科学基金项目（面上项目，重点项目，重大项目）