Mixotrophic basis of Atlantic oligotrophic ecosystems
Mixotrophic basis of Atlantic oligotrophic ecosystems
复制标题
DOI：
10.1073/pnas.1118179109
复制
发表时间：
2012-04-10
影响因子：
11.1
通讯作者：
Zubkov, Mikhail V.
中科院分区：
文献类型：
--
作者：
Hartmann, Manuela;Grob, Carolina;Zubkov, Mikhail V.
寡营养亚热带环流是最大的海洋生态系统，覆盖地球表面的40%以上。单细胞蓝细菌和最小的藻类（质体原生生物）在这些生态系统中占主导地位的CO2固定，竞争溶解的无机营养物质。在这里，我们提出了直接的证据，从表面混合层的亚热带环流和邻近的赤道和温带地区的大西洋，收集在三个大西洋经向断面巡航连续几年，浮游细菌的食质体和无质体原生生物在可比的速度。在光照和黑暗条件下，噬菌率相似。此外，由于其较高的丰度，这是质体原生生物，而不是无质体形式，控制这些沃茨中的噬菌性。这些发现改变了我们对开放海洋食物网功能的基本认识，因为质体原生生物现在应该被认为是寡营养环流中主要的食菌动物和主要的CO2固定剂。
Oligotrophic subtropical gyres are the largest oceanic ecosystems, covering >40% of the Earth's surface. Unicellular cyanobacteria and the smallest algae (plastidic protists) dominate CO2 fixation in these ecosystems, competing for dissolved inorganic nutrients. Here we present direct evidence from the surface mixed layer of the subtropical gyres and adjacent equatorial and temperate regions of the Atlantic Ocean, collected on three Atlantic Meridional Transect cruises on consecutive years, that bacterioplankton are fed on by plastidic and aplastidic protists at comparable rates. Rates of bacterivory were similar in the light and dark. Furthermore, because of their higher abundance, it is the plastidic protists, rather than the aplastidic forms, that control bacterivory in these waters. These findings change our basic understanding of food web function in the open ocean, because plastidic protists should now be considered as the main bacterivores as well as the main CO2 fixers in the oligotrophic gyres.