Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, PR China.
School of Pharmaceutical Science, Jiangnan University, Wuxi 214122, PR China.
Water Res. 2022 May 15;215:118242. doi: 10.1016/j.watres.2022.118242. Epub 2022 Mar 2.
Harmful cyanobacterial blooms (HCBs), mainly caused by eutrophication, have deleterious impacts on water resources and pose a great threat to human health and natural ecosystems. Thus, an environmentally-friendly method to inhibit HCBs is urgently needed. Learning from nature, herein, natural product cercosporin, produced by the fungi Cercospora to damage plant cells under natural sunlight, was developed as a powerful photosensitive algicidal reagent to inhibit HCBs. Microcystis aeruginosa could be severely inactivated by 20 μM cercosporin in 36 h with 95% inhibition ratio under 23 W compact fluorescent light irradiation. Further mechanism investigation showed that algal cell walls and membranes along with the antioxidant and photosynthetic systems were damaged via two mechanisms, those being, reactive oxygen species generation and cell adsorption. More importantly, the practical applicability of cercosporin was demonstrated by its effectiveness in a 2 L-scale photoinactivation experiment using cyanobacterial blooms from Taihu Lake, China under natural sunlight with a lower dosage of cercosporin (7.5 μM). This study established the bifunctional mechanisms by which cercosporin inactivates HCBs, opening design possibilities for the development of novel photosensitive algicidal reagents to control HCBs.
有害的蓝藻水华（HCBs）主要由富营养化引起，对水资源具有有害影响，并对人类健康和自然生态系统构成巨大威胁。因此，迫切需要一种环保的方法来抑制 HCBs。受自然启发，本文开发了天然产物蛇孢菌素，该物质由真菌尾孢菌在自然光照下产生，以破坏植物细胞，被开发为一种强大的光敏杀藻试剂来抑制 HCBs。在 23 W 紧凑型荧光灯照射下，浓度为 20 μM 的蛇孢菌素在 36 h 内可将铜绿微囊藻的抑制率达到 95%，严重失活。进一步的机制研究表明，藻类细胞壁和细胞膜以及抗氧化和光合作用系统通过两种机制被破坏，即活性氧的产生和细胞吸附。更重要的是，通过在自然阳光下使用来自中国太湖的蓝藻水华进行的 2 L 规模的光灭活实验，证明了蛇孢菌素的实际适用性，其所需的蛇孢菌素剂量更低（7.5 μM）。该研究确立了蛇孢菌素灭活 HCBs 的双重作用机制，为开发新型光敏杀藻试剂来控制 HCBs 提供了设计可能性。
