Understanding the ancestral transition from anaerobic to aerobic lifestyles is essential for comprehending life’s early evolution. However, the biological adaptations occurring during this crucial transition remain largely unexplored. Thiamine is an important cofactor involved in central carbon metabolism and aerobic respiration. Here, we explored the phylogenetic and global distribution of thiamine-auxotrophic and thiamine-prototrophic bacteria based on the thiamine biosynthetic pathway in 154 838 bacterial genomes. We observed strong coincidences of the origin of thiamine-synthetic bacteria with the “Great Oxygenation Event” (GOE), indicating that thiamine biosynthesis in bacteria emerged as an adaptation to aerobic respiration. Furthermore, we demonstrated that thiamine-mediated metabolic interactions are fundamental factors influencing the assembly and diversity of bacterial communities by a global survey across 4245 soil samples. Through our newly established SIP-metabolic modeling method, we uncovered the active utilization of thiamine-mediated metabolic interactions by bacterial communities in response to changing environments, thus revealing an environmental adaptation strategy employed by bacteria at the community level. Our study demonstrates the widespread thiamine-mediated metabolic interactions in bacterial communities, and their crucial roles in setting the stage for an evolutionary transition from anaerobic to aerobic lifestyles and subsequent environmental adaptation. These findings provide new insights into early bacterial evolution and their subsequent growth and adaptations to environments.

中文翻译：

---

通过硫胺素生物合成和硫胺素介导的代谢相互作用进行细菌生长和环境适应


了解祖先从无氧生活方式到有氧生活方式的转变对于理解生命的早期进化至关重要。然而，在这一关键转变期间发生的生物适应在很大程度上仍未得到探索。硫胺素是参与中心碳代谢和有氧呼吸的重要辅助因子。在这里，我们基于 154 838 个细菌基因组中的硫胺素生物合成途径，探讨了硫胺素营养缺陷型和硫胺素原养型细菌的系统发育和整体分布。我们观察到硫胺素合成细菌的起源与“大氧化事件”（GOE）有很强的一致性，这表明细菌中硫胺素的生物合成是为了适应有氧呼吸而出现的。此外，我们通过对 4245 个土壤样本的全球调查证明，硫胺素介导的代谢相互作用是影响细菌群落组装和多样性的基本因素。通过我们新建立的SIP代谢建模方法，我们发现细菌群落积极利用硫胺素介导的代谢相互作用来响应环境变化，从而揭示了细菌在群落水平上采用的环境适应策略。我们的研究证明了细菌群落中广泛存在的硫胺素介导的代谢相互作用，以及它们在为从无氧生活方式到有氧生活方式的进化转变以及随后的环境适应奠定基础方面的关键作用。这些发现为早期细菌进化及其随后的生长和对环境的适应提供了新的见解。