School of Environmental Engineering, Nanjing Institute of Technology, Nanjing 211167, China.
Three Gorges Beijing Enterprises Nanjing Water Group Co., Ltd., Nanjing 210000, China.
Int J Environ Res Public Health. 2022 Apr 30;19(9):5485. doi: 10.3390/ijerph19095485.
Frequent outbreaks of harmful algal blooms (HABs) represent one of the most serious outcomes of eutrophication, and light radiation plays a critical role in the succession of species. Therefore, a better understanding of the impact of light radiation is essential for mitigating HABs. In this study, and non-toxic and toxic were mono-cultured and co-cultured to explore algal responses under different nutrient regimes. Comparisons were made according to photosynthetically active radiation (PAR), UV-B radiation exerted oxidative stresses, and negative effects on the photosynthesis and growth of three species under normal growth conditions, and algal adaptive responses included extracellular polymeric substance (EPS) production, the regulation of superoxide dismutase (SOD) activity, photosynthetic pigments synthesis, etc. Three species had strain-specific responses to UV-B radiation and toxic was more tolerant and showed a higher adaptation capability to UV-B in the mono-cultures, including the lower sensitivity and better self-repair efficiency. In addition to stable μ in PAR ad UV-B treatments, higher EPS production and enhanced production of photosynthetic pigments under UV-B radiation, toxic showed a better recovery of its photosynthetic efficiency. Nutrient enrichment alleviated the negative effects of UV-B radiation on three species, and the growth of toxic was comparable between PAR and UV-B treatment. In the co-cultures with nutrient enrichment, gradually outcompeted in the PAR treatment and UV-B treatment enhanced the growth advantages of , when toxic showed a greater competitiveness. Overall, our study indicated the adaptation of typical algal species to ambient UV-B radiation and the stronger competitive ability of toxic in the UV-radiated waters with severer eutrophication.
频繁爆发的有害藻华（HABs）是富营养化的最严重后果之一，而光辐射在物种演替中起着关键作用。因此，更好地了解光辐射的影响对于减轻 HABs 至关重要。在这项研究中，无毒和有毒藻分别进行了纯培养和共培养，以探索不同营养条件下藻类的响应。根据光合有效辐射（PAR）、UV-B 辐射对三种物种光合作用和生长的氧化应激和负面影响进行了比较，在正常生长条件下，以及藻类的适应性响应，包括细胞外聚合物物质（EPS）的产生、超氧化物歧化酶（SOD）活性的调节、光合色素的合成等。三种藻对 UV-B 辐射具有特定的反应，在纯培养中，无毒藻对 UV-B 的耐受性更高，表现出更高的适应能力，包括更低的敏感性和更好的自我修复效率。除了在 PAR 和 UV-B 处理中稳定的 μ 外，有毒藻在 UV-B 辐射下还表现出更高的 EPS 产生和增强的光合色素合成，从而更好地恢复其光合效率。营养富集会减轻 UV-B 辐射对三种藻的负面影响，并且在营养富集会使无毒藻的生长与 PAR 处理相当。在营养富集的共培养中，无毒藻逐渐在 PAR 处理中占据优势，而 UV-B 处理增强了有毒藻的生长优势，当有毒藻表现出更大的竞争力时更是如此。总体而言，我们的研究表明，典型藻类物种对环境 UV-B 辐射的适应性以及在富营养化更严重的受 UV 辐射水域中有毒藻更强的竞争力。
