Israel Oceanographic and Limnological Research, Tel-Shikmona 8030, Haifa, 310800, Israel.
Department of Biology, Technion-Israel Institute of Technology, Technion City, Haifa, 3200003, Israel.
FEMS Microbiol Ecol. 2021 Mar 10;97(3). doi: 10.1093/femsec/fiab020.
The marine macroalgae Ulva sp. is considered an ecosystem engineer in rocky shores of temperate waters worldwide. Ulva sp. harbors a rich diversity of associated microbial epibionts, which are known to affect the algae's typical morphological development and 'health'. We examined the interaction between airborne microbes derived from atmospheric aerosols and Ulva ohnoi growth and physiological state. Specifically, we measured U. ohnoi growth rates and photosynthetic efficiency (Fv/Fm), alongside its microbial epibionts abundance, activity and diversity following dust (containing nutrients and airborne microorganisms) or UV-treated dust (only nutrients) amendments to filtered seawater. Parallel incubations with epibionts-free U. ohnoi (treated with antibiotics that removed the algae epibionts) were also tested to specifically examine if dust-borne microbes can replenish the epibiont community of U. ohnoi. We show that viable airborne microbes can restore U. ohnoi natural microbial epibionts communities, thereby keeping the seaweed alive and 'healthy'. These results suggest that microbes delivered through atmospheric aerosols can affect epiphyte biodiversity in marine flora, especially in areas subjected to high annual atmospheric dust deposition such as the Mediterranean Sea.
海洋大型藻类石莼属在世界范围内被认为是温带潮间带生态系统的工程师。石莼属含有丰富多样的相关微生物附生物，这些微生物附生物已知会影响藻类的典型形态发育和“健康”。我们研究了来自大气气溶胶的空气传播微生物与石莼生长和生理状态之间的相互作用。具体来说，我们测量了 U. ohnoi 的生长速率和光合效率（Fv/Fm），以及在过滤海水中添加灰尘（含有营养物质和空气传播微生物）或经过 UV 处理的灰尘（仅含有营养物质）后，其微生物附生物的丰度、活性和多样性。还进行了没有附生物的 U. ohnoi（用去除藻类附生物的抗生素处理）的平行培养实验，以专门研究空气中传播的微生物是否可以补充 U. ohnoi 的附生物群落。我们表明，有活力的空气传播微生物可以恢复 U. ohnoi 天然微生物附生物群落，从而使海藻保持活力和“健康”。这些结果表明，通过大气气溶胶输送的微生物可以影响海洋植物中的附生生物多样性，特别是在像地中海这样每年大气尘埃沉积量较高的地区。
