Carbon use efficiency (CUE) is a key characteristic of microbial physiology and underlies community-level responses to changing environments. Yet, we currently lack general empirical insights into variation in microbial CUE at the level of individual taxa. Here, through experiments with 29 strains of environmentally isolated bacteria, we find that bacterial CUE typically responds either positively to temperature, or has no discernible response, within biologically meaningful temperature ranges. Using a global data synthesis, we show that these results are generalisable across most culturable groups of bacteria. This variation in the thermal responses of bacterial CUE is taxonomically structured, and stems from the fact that relative to respiration rates, bacterial population growth rates typically respond more strongly to temperature, and are also subject to weaker evolutionary constraints. Our results provide new insights into microbial physiology, and a basis for more accurately modelling the effects of thermal fluctuations on complex microbial communities.

中文翻译：

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细菌碳利用效率的温度依赖性的系统变化

碳利用效率 (CUE) 是微生物生理学的一个关键特征，是社区对不断变化的环境做出反应的基础。然而，我们目前缺乏对个体分类群水平的微生物 CUE 变化的一般经验见解。在这里，通过对 29 种环境分离细菌的实验，我们发现细菌 CUE 在具有生物学意义的温度范围内通常对温度有积极反应，或者没有明显的反应。使用全局数据合成，我们表明这些结果在大多数可培养的细菌群中是可推广的。细菌 CUE 热响应的这种变化在分类学上是结构化的，并且源于这样一个事实：相对于呼吸速率，细菌种群增长率通常对温度的响应更强烈，并且还受到较弱的进化约束。我们的结果提供了对微生物生理学的新见解，并为更准确地模拟热波动对复杂微生物群落的影响奠定了基础。