Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, Shandong, China.
Shanxi Agricultural University, Taigu, 030801, Shanxi, China.
Environ Sci Pollut Res Int. 2021 May;28(17):21256-21265. doi: 10.1007/s11356-020-11969-5. Epub 2021 Jan 7.
Gracilaria blodgettii and Gracilaria lemaneiformis are often adopted as tools to purify aquaculture tail water. However, there has been such phenomenon that high temperature in summer restricts the process of aquaculture. To explore the adaptive capacity of G. blodgettii and G. lemaneiformis, we experimented them and cultured for 12 days under three temperatures (20, 25, and 30 °C) and three levels of multiple nitrogen sources (0.12, 0.6 and 4.4 mg L). Their growth, photosynthetic characteristics, and biochemical compositions including the contents of pigments and soluble protein were determined to investigate the single and interactive effects of temperatures and nitrogen levels on these two species. The results showed that in terms of G. blodgettii, the higher growth rate and more pigment (chlorophyll a and carotenoids) contents were observed at 25 and 30 °C in comparison to 20 °C, and the pigments showed maximum contents at 25 °C. More nitrogen improved the growth rate, net photosynthetic rate (P) at 25 and 30 °C, F/F at 20 °C, maximal photosynthetic electron transfer rate (ETR), as well as soluble protein content at 20 and 25 °C. Additionally, the growth rate, P, and ETR of G. lemaneiformis all showed a decline as increasing temperature; analogously high nitrogen concentration increased the growth rate at 25 and 30 °C, F/F at each temperature, ETR, and pigments contents at 20 °C, as well as soluble protein content at 20 and 25 °C. Conclusions indicated that high temperature restricted the growth rate, inhibited photosynthetic characteristics, and decreased the soluble protein content of G. lemaneiformis. The reduced photosynthetic performance, pigments, and soluble protein contents of G. blodgettii were noted under similar conditions. However, nitrogen enrichment induced the greater resistant level to high temperature, and G. blodgettii showed better response. These findings suggested that these two Gracilaria species possessed a certain adaptability to tail water from aquaculture at high temperature and G. blodgettii can resist more to. Therefore, it seems to be an alternative and workable scheme to adopt some suitable macroalgae to optimize the solution to present purification of aquaculture wastewater or eutrophic waters under high temperature.
江蓠属的江蓠.blodgettii 和江蓠.lemaneiformis 常被用作净化水产养殖尾水的工具。然而，夏季高温会限制水产养殖过程，这一现象时有发生。为了探索江蓠.blodgettii 和江蓠.lemaneiformis 的适应能力，我们在三种温度（20、25 和 30°C）和三种氮源浓度（0.12、0.6 和 4.4mg/L）下对它们进行了为期 12 天的实验和培养。测定了它们的生长、光合特性以及包括色素和可溶性蛋白含量在内的生化成分，以研究温度和氮水平对这两个物种的单一和交互作用。结果表明，就江蓠.blodgettii 而言，与 20°C 相比，25 和 30°C 下生长速度更快，色素（叶绿素 a 和类胡萝卜素）含量更高，25°C 下色素含量最高。更多的氮可以提高生长速度、25 和 30°C 下的净光合速率（P）、20°C 下的 F/F、最大光合电子传递速率（ETR）以及 20 和 25°C 下的可溶性蛋白含量。此外，江蓠.lemaneiformis 的生长速度、P 和 ETR 均随温度升高而下降；类似地，高氮浓度增加了 25 和 30°C 下的生长速度、各温度下的 F/F、ETR 以及 20°C 下的色素含量，以及 20 和 25°C 下的可溶性蛋白含量。结论表明，高温限制了江蓠.lemaneiformis 的生长速度，抑制了其光合特性，降低了其可溶性蛋白含量。在类似条件下，江蓠.blodgettii 的光合性能、色素和可溶性蛋白含量下降。然而，氮的富集诱导了对高温更强的抵抗水平，江蓠.blodgettii 表现出更好的响应。这些发现表明，这两种江蓠属物种对高温水产养殖尾水具有一定的适应性，而且江蓠.blodgettii 的适应性更强。因此，采用一些合适的大型藻类来优化高温下的水产养殖废水或富营养化水的净化方案似乎是一种替代和可行的方案。
