The response pattern of soil bacterial communities to drought events has been characterized from short-term laboratory desiccation and in naturally arid soils, but the resistance of soil bacteria to persistently long periods of desiccation remains largely unknown. This study assessed the abundance and composition of bacteria in 24 historical soils air-dried for more than 70 years, by quantification and high-throughput sequencing analyses of 16S rRNA genes. All soils contained measurable abundances of bacteria varying from 10³ to 10⁸ gene copies g⁻¹ soil and contrasting community compositions were observed in soils with different land histories, suggesting that the detected bacteria were indigenous to the field. A 28-day soil rewetting incubation significantly increased the bacterial gene abundance in soils, indicating some bacteria in these soils were still alive and quickly resuscitated. Among all identified taxa, Paenibacillus, Cohnella and two unclassified Bacillales genera within the phylum Firmicutes showed growth in the highest number of soils (≥12 soils), whereas Bacillales genera Tumebacillus, Alicyclobacillus and Brevibacillus displayed the strongest growth activity (>1000-fold increase in gene abundance) following rewet. Some Actinobacteria and Proteobacteria genera also showed relatively high activity following the rewet, suggesting that the tolerance to prolonged desiccation is a common trait across phylogenetically divergent microbes. The present study thus confirmed the value of desiccated soils for detecting the composition difference of bacteria, and provided evidence for strong adaptation of some bacteria to long-term desiccation and extreme osmotic change.

土壤细菌群落对干旱事件的响应模式已通过短期实验室干燥和自然干旱土壤表征，但土壤细菌对持续长期干燥的抗性仍然未知。这项研究通过对16S rRNA基因进行定量和高通量测序分析，评估了风干了70多年的24个历史土壤中细菌的丰度和组成。所有土壤均含有可测量的细菌丰富度，其细菌拷贝数为10 ³至10 ^8个基因g ^-1在具有不同土地历史的土壤中观察到土壤和相反的群落组成，这表明所检测到的细菌是该田间的本地细菌。28天的土壤再湿润培养显着增加了土壤中细菌基因的丰度，表明这些土壤中的某些细菌仍然存活并迅速复苏。在所有标识的类群，芽孢杆菌，Cohnella和两个生产型芽孢杆菌的内门属厚壁菌均呈增长态势土壤中（≥12土壤）的最高数量，而芽孢杆菌属Tumebacillus，脂环和短短芽孢再润湿后显示出最强的生长活性（基因丰度增加> 1000倍）。在回潮后，一些放线菌属和变形杆菌属也显示出相对较高的活性，这表明对长期干燥的耐受性是系统发生分歧的微生物的共同特征。因此，本研究证实了干燥土壤对检测细菌组成差异的价值，并为某些细菌对长期干燥和极端渗透变化的强烈适应提供了证据。