Jeon Youchul, Struewing Ian, Clauson Kale, Reetz Nathan, Fairchild Ned, Goeres-Priest Lacey, Dreher Theo W, Labiosa Rochelle, Carpenter Kurt D, Rosen Barry H, Villegas Eric N, Lu Jingrang
U.S. Environmental Protection Agency, Office of Research and Development, Gulf Breeze, FL, USA.
U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA.
Harmful Algae. 2025 Feb;142:102802. doi: 10.1016/j.hal.2025.102802. Epub 2025 Jan 17.
The excessive growth of harmful cyanobacteria, including Dolichospermum (formerly known as Anabaena), in freshwater bodies has become a pressing global concern. However, detailed information about the role of Dolichospermum in shaping bloom dynamics and producing cyanotoxins is limited. In this study, a bloom event dominated by Dolichospermum spp. at Detroit Lake (Oregon, USA) was examined from 2019 to 2021. In 2019, early summer cyanobacterial community succession reached up to 8.7 % of total phytoplankton abundance. Dolichospermum was the major microcystin (MC)-producing genus, with peak MC levels of 7.34 μg L. The presence of MCs was strongly correlated with the abundance of Dolichospermum (r = 0.84, p < 0.05) and MC synthetase gene, mcyE-Ana (r = 0.63, p < 0.05). Metabolic analyses further showed that the presence of nif/pst genes linked to nitrogen and phosphorus metabolism was dominated by Dolichospermum from the bloom onset until September. In addition, the abundance of Dolichospermum was significantly correlated with the abundance of nitrogen-fixing nif-Ana gene (r = 0.62, p < 0.05). As the lake experienced a longer N and P scarcity period (May to September), the N-fixing Dolichospermum was able to dominate over other non-fixing cyanobacteria present, including Microcystis and Planktothrix. Overall, our results facilitate a better understanding of the organism and will help working toward managing/predicting future blooms.
包括束丝藻属（原名为鱼腥藻属）在内的有害蓝藻在淡水水体中的过度生长已成为全球紧迫的关注问题。然而，关于束丝藻在形成水华动态和产生蓝藻毒素方面作用的详细信息有限。在本研究中，对美国俄勒冈州底特律湖2019年至2021年期间以束丝藻属为主导的一次水华事件进行了研究。2019年，初夏蓝藻群落演替达到浮游植物总丰度的8.7%。束丝藻是主要产生微囊藻毒素（MC）的属，MC峰值水平为7.34微克/升。MC的存在与束丝藻的丰度（r = 0.84，p < 0.05）和MC合成酶基因mcyE - Ana（r = 0.63，p < 0.05）密切相关。代谢分析进一步表明，从水华开始到9月，与氮和磷代谢相关的nif/pst基因的存在以束丝藻为主导。此外，束丝藻的丰度与固氮nif - Ana基因的丰度显著相关（r = 0.62，p < 0.05）。由于该湖经历了更长的氮和磷短缺期（5月至9月），固氮的束丝藻能够在包括微囊藻和席藻在内的其他非固氮蓝藻中占据主导地位。总体而言，我们的结果有助于更好地了解该生物，并将有助于对未来水华进行管理/预测。
