Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), China.
Department of Ocean Engineering and Marine Sciences, Florida Institute of Technology, Melbourne, FL, United States.
Water Res. 2022 Jul 1;219:118565. doi: 10.1016/j.watres.2022.118565. Epub 2022 May 12.
Harmful algal blooms (HABs) may quickly travel and inoculate new water bodies via currents and runoff in estuaries. The role of in-situ prokaryotic communities in the re-establishment and growth of inoculated algal blooms remains unknown. A novel on-board incubation experiment was employed to simulate the sudden surge of algal blooms to new estuarine waters and reveal possible outcomes. A dinoflagellate (Amphidinium carterae) and a diatom species (Thalassiosira weissflogii) which had bloomed in the Pearl River Estuary (PRE) area were cultured to bloom densities and reintroduced back into PRE natural seawaters. The diatom showed better adaptation ability to the new environment and increased significantly after the incubation. Simultaneously, particle-attached (PA) prokaryotic community structure was strongly influenced by adding of the diatom, with some opportunistic prokaryotes significantly enhanced in the diatom treatment. Whereas the dinoflagellate population did not increase following incubation, and their PA prokaryotic community showed no significant differences relative to the control. Metagenomic analyzes revealed that labile carbohydrates and organic nitrogen produced by the diatom contributed to the surge of certain PA prokaryotes. Genomic properties of a bacteria strain, which is affiliated with genus GMD16E07 (Planctomycetaceae) and comprised up to 50% of PA prokaryotes in the diatom treatment, was described here for the first time. Notably, the association of Planctomycetaceae and T. weissflogii likely represents symbiotic mutualism, with the diatom providing organic matter for Planctomycetaceae and the bacteria supplying vitamins and detoxifying nitriles and hydrogen peroxides in exchange. Therefore, the close association between Planctomycetaceae and T. weissflogii promoted the growth of both populations, and eventually facilitated the diatom bloom establishment.
有害藻华（HABs）可能会通过河口的水流和径流迅速传播并接种新的水体。原位原核微生物群落在接种藻华的再建立和生长中的作用尚不清楚。本研究采用一种新型的船上孵育实验来模拟藻华对新河口水域的突然涌入，并揭示可能的结果。培养了在珠江口（PRE）地区爆发的一种腰鞭毛藻（Amphidinium carterae）和一种硅藻（Thalassiosira weissflogii），使其达到爆发密度，并重新引入 PRE 天然海水中。硅藻对新环境表现出更好的适应能力，孵育后显著增加。同时，添加硅藻强烈影响了颗粒附着（PA）原核微生物群落结构，一些机会主义原核微生物在硅藻处理中显著增强。然而，在孵育后，腰鞭毛藻的数量没有增加，其 PA 原核微生物群落与对照组相比没有显著差异。宏基因组分析表明，硅藻产生的可利用碳水化合物和有机氮促进了某些 PA 原核微生物的激增。本文首次描述了一个隶属于 GMD16E07 属（浮霉菌科）的细菌菌株的基因组特性，该菌株占硅藻处理中 PA 原核微生物的 50%。值得注意的是，浮霉菌科和 T. weissflogii 的关联可能代表共生互利关系，硅藻为浮霉菌科提供有机物，而细菌则提供维生素，并在交换中解毒腈和过氧化氢。因此，浮霉菌科和 T. weissflogii 的密切关联促进了两个种群的生长，最终促进了硅藻的爆发。
