Ecology of Marine Plankton, Sorbonne Université, CNRS, UMR7144, Station Biologique de Roscoff, Roscoff, 29680, France.
Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, USA.
J Phycol. 2021 Apr;57(2):435-446. doi: 10.1111/jpy.13125. Epub 2021 Mar 14.
In the Arctic Ocean, the small green alga Micromonas polaris dominates picophytoplankton during the summer months but is also present in winter. It has been previously hypothesized to be phago-mixotrophic (capable of bacteria ingestion) based on laboratory and field experiments. Prey uptake was analyzed in several M. polaris strains isolated from different regions and depths of the Arctic Ocean and in Ochromonas triangulata, a known phago-mixotroph used as a control. Measuring ingestion of either fluorescent beads or fluorescently labeled bacteria by flow cytometry, we found no evidence of phago-mixotrophy in any M. polaris strain while O. triangulata was ingesting both beads and bacteria. In addition, in silico predictions revealed that members of the genus Micromonas lack a genetic signature of phagocytotic capacity.
在北极海洋中，小绿藻 Micromonas polaris 在夏季几个月中主导着微微型浮游植物，但在冬季也存在。先前基于实验室和野外实验的研究假设其为噬菌混合营养型（能够吞噬细菌）。我们分析了从北极海洋不同区域和深度分离的几种 M. polaris 菌株以及用作对照的已知噬菌混合营养型的 Ochromonas triangulata 的猎物摄取情况。通过流式细胞术测量对荧光珠或荧光标记细菌的摄取情况，我们发现任何 M. polaris 菌株都没有噬菌混合营养的证据，而 O. triangulata 则同时摄取了珠和菌。此外，计算机预测显示，属 Micromonas 的成员缺乏吞噬能力的遗传特征。
