Li Jiping, Wang Ying, Fang Yuan, Lyu Xingsheng, Zhu Zixin, Wu Chenyang, Xu Zijie, Li Wei, Liu Naisen, Du Chenggong, Wang Yan
Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huaian 223300, China.
Jiangsu Key Laboratory for Eco-Agricultural Biotechnology Around Hongze Lake, Huaiyin Normal University, Huaian 223300, China.
Plants (Basel). 2025 Jan 3;14(1):121. doi: 10.3390/plants14010121.
Macrolide pollution has attracted a great deal of attention because of its ecotoxic effects on microalgae, but the role of phycospheric bacteria under antibiotic stress remains unclear. This study explored the toxic effects of erythromycin (ERY) on the growth and nitrogen metabolism of ; then, it analyzed and predicted the effects of the composition and ecological function of phycospheric bacteria on microalgae under ERY stress. We found that 0.1, 1.0, and 10 mg/L ERY inhibited the growth and chlorophyll of microalgae, but the microalgae gradually showed enhanced growth abilities over the course of 21 days. As the exposure time progressed, the nitrate reductase activities of the microalgae gradually increased, but remained significantly lower than that of the control group at 21 d. NO concentrations in all treatment groups decreased gradually and were consistent with microalgae growth. NO concentrations in the three treatment groups were lower than those in the control group during ERY exposure over 21 d. ERY changed the community composition and diversity of phycospheric bacteria. The relative abundance of bacteria, such as , , , , and , varied to different degrees. Metabolic functions, such ABC transporters, the microbial metabolism in diverse environments, and the biosynthesis of amino acids, were significantly upregulated in the treatments of higher concentrations (1.0 and 10 mg/L). Higher concentrations of ERY significantly inhibited nitrate denitrification, nitrous oxide denitrification, nitrite denitrification, and nitrite and nitrate respiration. The findings of this study suggest that phycospheric bacteria alleviate antibiotic stress and restore the growth of microalgae by regulating nitrogen metabolism in the exposure system.
大环内酯类污染因其对微藻的生态毒性效应而备受关注，但抗生素胁迫下藻际细菌的作用仍不清楚。本研究探讨了红霉素（ERY）对[微藻名称未给出]生长和氮代谢的毒性效应；然后，分析并预测了ERY胁迫下藻际细菌的组成和生态功能对微藻的影响。我们发现，0.1、1.0和10 mg/L的ERY抑制了微藻的生长和叶绿素含量，但在21天的过程中微藻逐渐表现出增强的生长能力。随着暴露时间的延长，微藻的硝酸还原酶活性逐渐增加，但在21天时仍显著低于对照组。所有处理组中的NO浓度逐渐降低，且与微藻生长一致。在21天的ERY暴露期间，三个处理组中的NO浓度均低于对照组。ERY改变了藻际细菌的群落组成和多样性。[细菌名称未给出]等细菌的相对丰度有不同程度的变化。在较高浓度（1.0和10 mg/L）处理中，ABC转运蛋白、不同环境中的微生物代谢和氨基酸生物合成等代谢功能显著上调。较高浓度的ERY显著抑制了硝酸盐反硝化、一氧化二氮反硝化、亚硝酸盐反硝化以及亚硝酸盐和硝酸盐呼吸。本研究结果表明，藻际细菌通过调节暴露系统中的氮代谢来减轻抗生素胁迫并恢复微藻的生长。
