Bacterial carbon use plasticity, phylogenetic diversity and the priming of soil organic matter
Bacterial carbon use plasticity, phylogenetic diversity and the priming of soil organic matter
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DOI：
10.1038/ismej.2017.43
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发表时间：
2017-08-01
期刊：
影响因子：
11
通讯作者：
Hungate, Bruce A.
中科院分区：
文献类型：
--
作者：
Morrissey, Ember M.;Mau, Rebecca L.;Hungate, Bruce A.
微生物在地球上进行大部分分解，调节生态系统中的碳(C)损失，从而影响气候。然而，微生物群落的特性和组成的变化如何影响生态系统的碳平衡还远不清楚。利用DNA的定量稳定同位素探针，我们展示了在添加不稳定的C(葡萄糖)后，单个细菌分类群如何影响土壤C循环。具体地说，我们表明，随着系统发育多样化的类群(占细菌群落的很大比例)转向额外的土壤碳利用来生长，土壤C的分解对添加葡萄糖的响应(正启动)发生了。我们的发现表明，许多微生物分类群表现出可塑性，因为大多数分类群根据环境条件改变了它们对葡萄糖和土壤有机质的使用。相反，表现出对葡萄糖的其他反应(减少生长或依赖葡萄糖进行额外生长)的细菌在系统发育上聚集在一起。这些结果表明，正启动可能是细菌对持续不稳定的C添加的典型反应，这与自然界中广泛存在的正启动效应是一致的。
Microorganisms perform most decomposition on Earth, mediating carbon (C) loss from ecosystems, and thereby influencing climate. Yet, how variation in the identity and composition of microbial communities influences ecosystem C balance is far from clear. Using quantitative stable isotope probing of DNA, we show how individual bacterial taxa influence soil C cycling following the addition of labile C (glucose). Specifically, we show that increased decomposition of soil C in response to added glucose (positive priming) occurs as a phylogenetically diverse group of taxa, accounting for a large proportion of the bacterial community, shift toward additional soil C use for growth. Our findings suggest that many microbial taxa exhibit C use plasticity, as most taxa altered their use of glucose and soil organic matter depending upon environmental conditions. In contrast, bacteria that exhibit other responses to glucose (reduced growth or reliance on glucose for additional growth) clustered strongly by phylogeny. These results suggest that positive priming is likely the prototypical response of bacteria to sustained labile C addition, consistent with the widespread occurrence of the positive priming effect in nature.