State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, The Institute of Environment, Resource, Soil and Fertilizers, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
Department of Agriculture and Biotechnology, Wenzhou Vocational College of Science and Technology, Wenzhou 325006, China.
Sci Total Environ. 2022 Nov 20;848:157698. doi: 10.1016/j.scitotenv.2022.157698. Epub 2022 Jul 28.
Nonylphenol (NP) toxicity limits the improvements in its algal remediation efficiency. This study comprehensively investigated the performance and mechanism of NaHCO-driving effects on NP-exposed algae. The results showed that NaHCO enhanced algal resistance to NP and the corresponding EC values increased 1.31-4.25 times. Further, the toxicological effects of NP reduced with increasing pyrenoid volume and chlorophyll and carotenoids production, and decreasing cellular damage degree. Moreover, the concentration of extracellular polymeric substances was enhanced and more NP adsorption sites were formed. Consistently, RNA-seq demonstrated significant expression alterations in genes related to energy metabolism, cellular synthesis, photosynthesis, and carbon fixation. Besides, NP biodegradation rate was increased by 15.2 % and 11.1 % in the 1, and 4 mg/L NP treatments, respectively. Identification of degradation intermediates and their toxicity via Ecological Structure Activity Relationship program showed that NaHCO accelerated sequential α-C removal from NP in algae with faster generation of less toxic metabolites, namely, 4-ethylphenol, 4-cresol and 4-hydroxybenzoic acid. This study provides new insights into the role of NaHCO in toxicity alleviation and metabolism enhancement of NP in algae and can assist NP bioremediation efforts in aquatic environment.
壬基酚 (NP) 的毒性限制了其在藻类修复效率方面的提升。本研究全面调查了 NaHCO 驱动对 NP 暴露藻类的作用效果及其机制。结果表明，NaHCO 增强了藻类对 NP 的抗性，相应的 EC 值增加了 1.31-4.25 倍。此外，NP 的毒性作用随着淀粉核体积和叶绿素及类胡萝卜素产量的增加以及细胞损伤程度的降低而降低。此外，细胞外聚合物的浓度增加，形成了更多的 NP 吸附位点。同样，RNA-seq 表明与能量代谢、细胞合成、光合作用和碳固定相关的基因表达显著改变。此外，NP 的生物降解率在 1mg/L 和 4mg/L NP 处理中分别提高了 15.2%和 11.1%。通过生态结构活性关系程序对降解中间产物及其毒性进行鉴定表明，NaHCO 加速了 NP 在藻类中α-C 的顺序去除，生成了更快、毒性更小的代谢物，即 4-乙基苯酚、4-甲酚和 4-羟基苯甲酸。本研究为 NaHCO 在藻类中 NP 毒性缓解和代谢增强中的作用提供了新的见解，并可协助水生环境中 NP 的生物修复工作。
