Flagellar motility is a key bacterial trait as it allows bacteria to navigate their immediate surroundings. Not all bacteria are capable of flagellar motility, and the distribution of this trait, its ecological associations, and the life history strategies of flagellated taxa remain poorly characterized. We developed and validated a genome-based approach to infer the potential for flagellar motility across 12 bacterial phyla (26 192 genomes in total). The capacity for flagellar motility was associated with a higher prevalence of genes for carbohydrate metabolism and higher maximum potential growth rates, suggesting that flagellar motility is more prevalent in environments with higher carbon availability. To test this hypothesis, we applied a method to infer the prevalence of flagellar motility in whole bacterial communities from metagenomic data, and quantified the prevalence of flagellar motility across 4 independent field studies that each captured putative gradients in soil carbon availability (148 metagenomes). As expected, we observed a positive relationship between the prevalence of bacterial flagellar motility and soil carbon availability in all datasets. Since soil carbon availability is often correlated with other factors that could influence the prevalence of flagellar motility, we validated these observations using metagenomic data acquired from a soil incubation experiment where carbon availability was directly manipulated with glucose amendments. This confirmed that the prevalence of bacterial flagellar motility is consistently associated with soil carbon availability over other potential confounding factors. This work highlights the value of combining predictive genomic and metagenomic approaches to expand our understanding of microbial phenotypic traits and reveal their general environmental associations.

中文翻译：

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土壤细菌群落鞭毛运动的生态相关性

鞭毛运动是细菌的一个关键特征，因为它允许细菌在其周围环境中导航。并非所有细菌都具有鞭毛运动能力，并且这种性状的分布、其生态关联以及有鞭毛类群的生活史策略仍然知之甚少。我们开发并验证了一种基于基因组的方法来推断 12 个细菌门（总共 26 192 个基因组）鞭毛运动的潜力。鞭毛运动能力与碳水化合物代谢基因的较高患病率和较高的最大潜在生长率相关，这表明鞭毛运动在碳利用率较高的环境中更为普遍。为了检验这一假设，我们应用一种方法从宏基因组数据推断整个细菌群落中鞭毛运动的流行率，并在 4 个独立的实地研究中量化鞭毛运动的流行率，每个研究都捕获了土壤碳可用性的假定梯度（148 个宏基因组）。正如预期的那样，我们在所有数据集中观察到细菌鞭毛运动的流行率与土壤碳可用性之间存在正相关关系。由于土壤碳可用性通常与可能影响鞭毛运动普遍性的其他因素相关，因此我们使用从土壤孵化实验中获得的宏基因组数据验证了这些观察结果，其中碳可用性直接用葡萄糖改良剂进行操纵。这证实了细菌鞭毛运动的普遍性与土壤碳有效性的相关性高于其他潜在的混杂因素。这项工作强调了结合预测基因组和宏基因组方法的价值，以扩大我们对微生物表型性状的理解并揭示它们的一般环境关联。