Examining the interaction between free-living bacteria and iron in the global ocean
Examining the interaction between free-living bacteria and iron in the global ocean
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研究全球海洋中自由生活的细菌和铁之间的相互作用
DOI：
10.1002/essoar.10508036.1
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Pham A
中科院分区：
文献类型：
--
作者：
Pham A
海洋自由生活（FL）细菌在水体中吸收、转化和释放有机物质的过程中，在包括铁（Fe）在内的基本地球化学元素的循环中发挥着关键作用。与浮游植物类似，FL细菌的生长受到营养资源（如Fe）的调节，这些资源的低可用性可能会影响细菌与浮游植物的相互作用，从而对地球化学循环产生连锁效应。然而，限制FL细菌生长的因素及其在Fe循环中的作用的知识受到很大限制。在这里，我们明确表示FL，碳氧化细菌在三维全球海洋生物地球化学模型来解决这些问题。我们发现，虽然Fe可以在夏季出现在热带太平洋和高纬度地区，但FL细菌的生长最终受到世界上大多数海洋中不稳定溶解有机碳的可用性的控制。在铁限制区，FL细菌生物量对季节性铁限制区的铁吸收能力和常年低铁区的最低铁需求敏感。在我们的模型中，FL细菌对Fe的消耗在上层海洋中是显著的，它们与浮游植物对Fe的竞争影响浮游植物的生长动力学，并且可以使细菌变得更加碳限制。由于Fe吸收和释放之间的紧密耦合，FL细菌对海洋内部Fe分布的影响很小。展望未来，需要考虑其他细菌群和不同细菌代谢的未来工作，以探索细菌在海洋铁循环中的更广泛作用。在这方面，来自海洋观测计划的全球增长组学数据可以发挥至关重要的作用。
Marine free‐living (FL) bacteria play a key role in the cycling of essential biogeochemical elements, including iron (Fe), during their uptake, transformation and release of organic matter throughout the water column. Similar to phytoplankton, the growth of FL bacteria is regulated by nutritive resources such as Fe, and the low availability of these resources may influence bacterial interactions with phytoplankton, causing knock‐on effects for biogeochemical cycling. Yet, knowledge of the factors limiting the growth of FL bacteria and their role within the Fe cycle is poorly constrained. Here, we explicitly represent FL, carbon‐oxidizing bacteria in a three‐dimensional global ocean biogeochemistry model to address these questions. We find that although Fe can emerge as proximally limiting in the tropical Pacific and in high‐latitude regions during summer, the growth of FL bacteria is ultimately controlled by the availability of labile dissolved organic carbon over most of the world's oceans. In Fe‐limited regions, FL bacterial biomass is sensitive to their Fe uptake capability in seasonally Fe‐limitation regions and to their minimum Fe requirements in regions perennially low in Fe. Fe consumption by FL bacteria is significant in the upper ocean in our model, and their competition with phytoplankton for Fe affects phytoplankton growth dynamics and can make bacteria become more carbon limited. The impact of FL bacteria on the Fe distribution in the ocean interior is small due to a tight coupling between Fe uptake and release. Moving forward, future work that considers other bacteria groups and different bacterial metabolisms is needed to explore the broader role of bacteria in ocean Fe cycling. In this context, the global growing’ omics data from ocean observing programs can play a crucial role.