Drivers of Bacterial Maintenance and Minimal Energy Requirements.
Drivers of Bacterial Maintenance and Minimal Energy Requirements.
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细菌维持和最小能量要求的驱动因素。
DOI：
10.3389/fmicb.2017.00031
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发表时间：
2017
影响因子：
5.2
通讯作者：
Hoehler T
中科院分区：
文献类型：
--
作者：
Kempes CP;van Bodegom PM;Wolpert D;Libby E;Amend J;Hoehler T
微生物通过各种过程维持自身。当资源可用性下降时，可以减少或完全关闭其中的一些流程。在具有充足底物供应的纯培养条件下，最大生长速率与维持所投入的能量之间的关系已被广泛报道。然而，在资源谱的另一端，细菌受到能量的极大限制，以至于没有生长发生，新陈代谢仅限于最基本的功能。这些最低能量要求被称为基本功率要求。虽然这两个方面看起来彼此不同，但它们都可能是一系列受管制的维护过程的组成部分。在这里，我们分析了跨物种的权衡在细胞生理学的范围内的细菌的大小和能量消耗，并确定在每个点的大小-能量谱沿着的贡献，以维持代谢。此外，通过探索这个框架内最简单的细菌-最受维护限制的影响-我们发现哪些过程变得最受限制。对于最小的物种，维护代谢收敛于总代谢，我们预测，维护是由蛋白质的修复为主。对于较大的物种，蛋白质修复的相对成本降低，预计维持代谢将主要由RNA组分的修复。这些结果提供了新的见解，哪些过程可能会受到监管的环境中，是非常有限的能源。
Microbes maintain themselves through a variety of processes. Several of these processes can be reduced or shut down entirely when resource availability declines. In pure culture conditions with ample substrate supply, a relationship between the maximum growth rate and the energy invested in maintenance has been reported widely. However, at the other end of the resources spectrum, bacteria are so extremely limited by energy that no growth occurs and metabolism is constrained to the most essential functions only. These minimum energy requirements have been called the basal power requirement. While seemingly different from each other, both aspects are likely components of a continuum of regulated maintenance processes. Here, we analyze cross-species tradeoffs in cellular physiology over the range of bacterial size and energy expenditure and determine the contributions to maintenance metabolism at each point along the size-energy spectrum. Furthermore, by exploring the simplest bacteria within this framework– which are most affected by maintenance constraints– we uncover which processes become most limiting. For the smallest species, maintenance metabolism converges on total metabolism, where we predict that maintenance is dominated by the repair of proteins. For larger species the relative costs of protein repair decrease and maintenance metabolism is predicted to be dominated by the repair of RNA components. These results provide new insights into which processes are likely to be regulated in environments that are extremely limited by energy.