Pseudomonas putida KT2440 is a desiccation-sensitive bacterium that loses culturability after 15 days of air desiccation. We have previously shown that P. putida KT2440 can develop a viable but nonculturable (VBNC) state after being exposed to desiccation stress and eventually recover when desiccated cells are rehydrated for at least 24 h. To determine which genes of transport, oxidation-reduction, and transcription processes could be involved in the return of P. putida KT2440 to the culturable state, a transcriptome analysis was carried out comparing the gene expression of non-desiccated samples with samples subjected to desiccation followed by 20 min of rehydration or desiccation followed by 24 h of rehydration. Desiccation stress triggered a VBNC state of P. putida. The major response was detected after 24 h of rehydration with 148 upregulated and 42 downregulated genes. During the VBNC state, P. putida activated transmembrane transport processes like that of siderophores through a TonB-dependent transporter and putative polyhydric alcohol transport systems. Prolonged rehydration with distilled water resuscitated P. putida KT2440 cells activating the catabolism of phenylalanine/tyrosine to provide energy and carbon for ubiquinone biosynthesis while maintaining a reduced protein synthesis. On the other hand, the interruption of the TonB-dependent receptor gene (PP_1446) increased desiccation survival of the mutant strain. The activation of the iron transport system (TonB-dependent siderophore receptor) and alcohol transport can be helping the VBNC state of P. putida. Activation of catabolism of phenylalanine/tyrosine and reduced protein synthesis was needed for resuscitation from the VBNC state.

中文翻译：

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脱水假单胞菌假单胞菌KT2440复苏过程中补液对转录组的影响

恶臭假单胞菌KT2440是一种对干燥敏感的细菌，在空气中干燥15天后会失去可培养性。先前我们已经证明恶臭假单胞菌KT2440在暴露于干燥压力后可以发展成活的但不可培养的（VBNC）状态，并在干燥的细胞重新水化至少24小时后最终恢复。为了确定恶臭假单胞菌KT2440返回可培养状态可能涉及哪些运输，氧化还原和转录过程的基因，进行了转录组分析，比较了未干燥样品和经过干燥的样品的基因表达。然后进行20分钟的补液或干燥，然后进行24小时的补液。干燥压力触发恶臭假单胞菌的VBNC状态。在补液24小时后，用148个上调和42个下调的基因检测到主要反应。在VBNC状态期间，恶臭假单胞菌通过依赖TonB的转运蛋白和推定的多元醇转运系统激活跨膜转运过程，如铁载体。用蒸馏水长时间补液可恢复恶臭假单胞菌KT2440细胞的活化，从而激活苯丙氨酸/酪氨酸的分解代谢，从而为泛醌生物合成提供能量和碳，同时保持减少的蛋白质合成。另一方面，TonB依赖受体基因（PP_1446）的中断增加了突变菌株的干燥存活率。铁转运系统（依赖TonB的铁载体受体）的激活和酒精转运可以帮助恶臭假单胞菌的VBNC状态。