Does microorganism stoichiometry predict microbial food web interactions after a phosphorus pulse?
Does microorganism stoichiometry predict microbial food web interactions after a phosphorus pulse?
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DOI：
10.1007/s00248-007-9353-8
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发表时间：
2008-08-01
影响因子：
3.6
通讯作者：
Medina-Sanchez, Juan M.
中科院分区：
文献类型：
--
作者：
Carrillo, Presentacion;Villar-Argaiz, Manuel;Medina-Sanchez, Juan M.
大气营养负荷引起的微生物食物网相互作用的变化的知识是至关重要的，以提高我们对原始生态系统中水生食物网结构的理解。三个实验模拟大气输入在不同的氮/磷（N/P）的比例进行了原位覆盖的季节性生物演替的中上层在高山西班牙湖泊。在所有的实验中，丰度，生物量，藻类细胞生物量，P-掺入率，P-细胞配额，和N/P比的藻类强烈响应于P-富集，而异养细菌保持相对不变。纤毛虫受到严重限制时，一个强大的藻类利用可用的P（水华生长或存储策略）导致短暂的（中期无冰实验）或慢性（后期无冰实验）的P-缺陷的细菌。相反，当细菌保持富磷（N/P20-24）时，纤毛虫达到最大发育。因此，细菌N/P比被证明是理解藻-菌关系和微生物食物网发展的关键因素。这项研究不仅证明了生活史策略，化学计量的营养含量和生长的相互依赖性，但也支持使用细菌的N/P阈值诊断纤毛虫的发展，一个很少研究的方面值得进一步关注。
Knowledge of variations in microbial food web interactions resulting from atmospheric nutrient loads is crucial to improve our understanding of aquatic food web structure in pristine ecosystems. Three experiments mimicking atmospheric inputs at different nitrogen/phosphorus (N/P) ratios were performed in situ covering the seasonal biological succession of the pelagic zone in a high-mountain Spanish lake. In all experiments, abundance, biomass, algal cell biovolume, P-incorporation rates, P-cell quota, and N/P ratio of algae strongly responded to P-enrichment, whereas heterotrophic bacteria remained relatively unchanged. Ciliates were severely restricted when a strong algal exploitation of the available P (bloom growth or storage strategies) led to transient (mid-ice-free experiment) or chronic (late ice-free experiment) P-deficiencies in bacteria. In contrast, maximum development of ciliates was reached when bacteria remained P-rich (N/P20-24). Hence, the bacterial N/P ratio proved be a key factor to understand the algae-bacteria relationship and microbial food web development. This study not only demonstrates the interdependence of life history strategies, stoichiometric nutrient content, and growth but also supports the use of bacterial N/P thresholds for diagnosing ciliate development, a little-studied aspect worthy of further attention.