Key Laboratory of Pollution Control Chemistry and Environmental Functional Materials for Qinghai-Tibet Plateau of the National Ethnic Affairs Commission, School of Chemistry and Environment, Southwest Minzu University, Chengdu 610041, China; Key Laboratory of General Chemistry of the National Ethnic Affairs Commission, School of Chemistry and Environment, Southwest Minzu University, Chengdu 610041, China.
Key Laboratory of Pollution Control Chemistry and Environmental Functional Materials for Qinghai-Tibet Plateau of the National Ethnic Affairs Commission, School of Chemistry and Environment, Southwest Minzu University, Chengdu 610041, China; Key Laboratory of General Chemistry of the National Ethnic Affairs Commission, School of Chemistry and Environment, Southwest Minzu University, Chengdu 610041, China.
Ecotoxicol Environ Saf. 2022 Nov;246:114185. doi: 10.1016/j.ecoenv.2022.114185. Epub 2022 Oct 13.
Periphyton has important ecological functions. It can even exist in environments with strong ultraviolet radiation. However, knowledge of periphyton under ultraviolet is limited, which limits the understanding and application of periphyton in environments with high ultraviolet radiation. In this study, immature periphyton (IMP) and mature periphyton (MP) under ultraviolet B (UVB) irradiation were investigated and compared in terms of physiological characteristics and bacterial community. Analysis of the physiological characteristics showed that the response patterns of IMP and MP to UVB were similar. IMP and MP could adapt to UVB of 1 W/m well. However, high-intensity UVB (2 and 3 W/m) reduced the periphyton biomass, inhibited photosynthesis and antioxidant enzyme activity and caused severe lipid peroxidation in both IMP and MP. Integrated Biological Response (IBR) analysis and toxicological model fitting showed that the ED values of UVB for IMP and MP were 1.25 and 1.50 W/m, respectively. 16 S rRNA gene analysis showed that in both IMP and MP, bacterial community composition, assembly and function were affected by UVB. In addition, the response of the bacterial community in IMP to UVB was stronger than that in MP. The diversity of the IMP community was inhibited by UVB, but that of the MP community was not. Proteobacteria and Deinococcus-Thermus are key microorganisms responsible for tolerance to UVB stress. Neutral community model fitting showed that both UVB and the development process caused the determinism of bacterial succession. However, UVB may weaken the deterministic process caused by development. Functional prediction showed that many metabolic functions of periphyton were inhibited by UVB in IMP and MP. However, UVB caused different changes (enhancement or inhibition) of some ecological functions in them. This study provides valuable information for understanding periphyton in environments with UVB radiation, which may be used to improve the application of periphyton in these environments.
底栖藻类具有重要的生态功能。它甚至可以存在于紫外线辐射很强的环境中。然而，关于紫外线条件下底栖藻类的知识有限，这限制了对高紫外线辐射环境中底栖藻类的理解和应用。本研究通过比较紫外线 B（UVB）照射下的未成熟底栖藻类（IMP）和成熟底栖藻类（MP），从生理特性和细菌群落两方面研究了底栖藻类在 UVB 下的情况。生理特性分析表明，IMP 和 MP 对 UVB 的响应模式相似。IMP 和 MP 可以很好地适应 1 W/m 的 UVB。然而，高强度 UVB（2 和 3 W/m）降低了底栖藻类的生物量，抑制了光合作用和抗氧化酶活性，导致 IMP 和 MP 均发生严重的脂质过氧化。综合生物反应（IBR）分析和毒理学模型拟合表明，IMP 和 MP 的 UVB 半数有效剂量（ED）值分别为 1.25 和 1.50 W/m。16S rRNA 基因分析表明，IMP 和 MP 的细菌群落组成、组装和功能均受到 UVB 的影响。此外，IMP 中细菌群落对 UVB 的响应强于 MP。UVB 抑制了 IMP 群落的多样性，但对 MP 群落的多样性没有影响。变形菌门和厚壁菌门-热微菌门是对 UVB 胁迫具有耐受性的关键微生物。中性群落模型拟合表明，UVB 和发育过程均导致了细菌演替的确定性。然而，UVB 可能会削弱由发育引起的确定性过程。功能预测表明，IMP 和 MP 中的许多底栖藻类代谢功能受到 UVB 的抑制。然而，UVB 对它们中的一些生态功能造成了不同的变化（增强或抑制）。本研究为理解 UVB 辐射环境中的底栖藻类提供了有价值的信息，这可能有助于提高底栖藻类在这些环境中的应用。
