The high cost of harvesting microalgae limits their industrial application. Fungal–microalgal pellets can efficiently harvest microalgae and enhance heavy-metal adsorption. However, the molecular response mechanism of fungal–microalgal pellets under heavy-metal stress remains unclear. Fungal–microalgal pellets in a photobioreactor were used as a research object, and a 98 % harvesting efficiency could be achieved with adding exogenous carbon and nitrogen at pH 5.0–6.0 for 12 h of co-culture. Humic acid- and tryptophan-rich proteins in extracellular polymeric substances (EPS) participate in Cd(II) complexation. The Cd(II) response in fungal-microalgal pellets involves amino acids, glucose, lipids, energy metabolism, and antioxidant systems. The turning point was at 48 h. Proline, histidine, and glutamine synthesis and the adenosine-triphosphate (ATP) binding cassette (ABC) transport pathway play important roles in resistance to Cd(II) biotoxicity. This study provides a reference for the large-scale cultivation of fungal-microalgal symbiotic pellets and the practical application for industrial heavy-metal wastewater.

中文翻译：

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用于重金属废水生物修复的光生物反应器中真菌-微藻颗粒的机理见解


收获微藻的高成本限制了它们的工业应用。真菌-微藻颗粒可以有效地收获微藻并增强重金属吸附。然而，真菌-微藻沉淀在重金属胁迫下的分子响应机制仍不清楚。光生物反应器中的真菌-微藻沉淀用作研究对象，通过在 pH 值为 5.0-6.0 的条件下添加外源碳和氮进行 12 小时的共培养，可以实现 98% 的收获效率。细胞外聚合物物质 （EPS） 中富含腐植酸和色氨酸的蛋白质参与 Cd（II） 络合。真菌-微藻颗粒中的 Cd（II） 反应涉及氨基酸、葡萄糖、脂质、能量代谢和抗氧化系统。转折点在 48 h。脯氨酸、组氨酸和谷氨酰胺合成以及三磷酸腺苷 （ATP） 结合盒 （ABC） 转运途径在抗 Cd（II） 生物毒性方面起重要作用。本研究为真菌-微藻共生颗粒的大规模培养和工业重金属废水的实际应用提供了参考。