Oxygen sensing drives predictable migrations in a microbial community
Oxygen sensing drives predictable migrations in a microbial community
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DOI：
10.1111/j.1462-2920.2008.01742.x
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发表时间：
2009-01-01
影响因子：
5.1
通讯作者：
Esteban, Genoveva F.
中科院分区：
文献类型：
--
作者：
Finlay, Bland J.;Esteban, Genoveva F.
氧传感广泛应用于从细菌到脊椎动物的好氧生物，并且在所有好氧生物中可能存在占主导地位的氧传感机制。我们跟踪人口迁移的10种较大的有氧纤毛虫生活在湖泊沉积物中，并在15米水柱的Esthwaite水在英国湖区（英国）。在这样做的过程中，我们发现湖泊沉积物和水柱的特征和动态在近2年的连续时间内表现出显著的可预测性。湖泊沉积物的变暖，加上低氧张力，导致好氧纤毛虫的出现，并迁移到水柱。并随着水体热层结的年塌陷，整个年循环不断重复。在一个不寻常的发现，我们发现，特定的纤毛虫物种似乎是“链接”到其他（功能不同）纤毛虫物种的合作伙伴，通过环境中的氧张力。最受欢迎的假设是，所有纤毛虫物种在一个特定的身体大小范围内寻求一个特定的，优选的氧张力。如果是这样的话，提供纤毛虫群落凝聚力的“水泥”实际上可能是首选的氧张力。我们研究的主要目的是澄清微生物迁移本身，而不是不同的纤毛虫物种一旦在水柱中建立自己的氧气梯度的反应。后者发生在生物体一起迁移出沉积物时，由环境氧张力驱动。
Oxygen sensing is widely practised by aerobic organisms ranging from bacteria to vertebrates, and a dominant oxygen-sensing mechanism may persist among all aerobes. We traced population migrations of 10 species of the larger aerobic ciliated protozoa living in lake sediment, and in the 15 m water column of Esthwaite Water in the English Lake District (UK). In so doing, we discovered that the character and dynamics of the lake sediment and water column were remarkably predictable in performance over a continuous period of almost 2 years. Increasing warming of the lake sediment, coupled with low oxygen tension, resulted in the emergence of aerobic ciliates out of the sediment and their migration into the water column. And with the annual collapse of thermal stratification in the water column, the whole annual cycle was repeated. In an unusual discovery, we found that particular ciliate species seemed to be 'linked' to other (functionally different) ciliate species partners via the ambient oxygen tension. The favoured hypothesis is that all ciliate species in a particular body-size range seek out a particular, preferred oxygen tension. If that is the case, the 'cement' providing the cohesion of the ciliate community might actually be the preferred oxygen tension. The principal aim of our study is to clarify the microbial migration itself, not the response of the different ciliate species to oxygen gradients once they have established themselves in the water column. The latter happens once the organisms have migrated out of the sediment together, driven by the ambient oxygen tension.