Amphibian’s skin bacterial community may help them to cope with several types of environmental perturbations, including osmotic stress caused by increased salinity. This work assessed whether an amphibian skin bacterium could increase its tolerance to NaCl after a long-term exposure to this salt. A strain of Erwinia toletana, isolated from the skin of Pelophylax perezi, was exposed to two salinity scenarios (with 18 g/L of NaCl): (1) long-term exposure (for 46 days; Et-NaCl), and (2) long-term exposure followed by a recovery period (exposure for 30 days to NaCl and then to LB medium for 16 days; Et-R). After exposure, the sensitivity of E. toletana clonal populations to NaCl was assessed by exposing them to 6 NaCl concentrations (LB medium spiked with NaCl) plus a control (LB medium). Genotypic alterations were assessed by PCR-based molecular typing method (BOX-PCR). The results showed that tolerance of E. toletana to NaCl slightly increased after the long-term exposure, EC₅₀ for growth were: 22.5 g/L (8.64–36.4) for Et-LB; 30.3 g/L (23.2–37.4) for Et-NaCl; and 26.1 g/L (19.332.9) for Et-R. Differences in metabolic activity were observed between Et-LB and Et-R and between Et-NaCl and Et-R, suggesting the use of different substrates by this bacterium when exposed to salinized environments. NaCl-induced genotypic alterations were not detected. This work suggests that E. toletana exposed to low levels of salinity, activate different metabolic pathways to cope with osmotic stress. These findings may be further explored to be used in bioaugmentation procedures through the supplementation with this bacterium of the skin microbiome of natural populations of amphibians exposed to salinization.

两栖动物的皮肤细菌群落可能帮助他们应对几种类型的环境扰动，包括盐度增加引起的渗透胁迫。这项工作评估了长期暴露于该盐下的两栖类皮肤细菌是否可以提高其对NaCl的耐受性。的应变欧文氏toletana，从皮肤分离侧褶perezi，暴露于两个盐度场景（18克/升的NaCl）：（1）长期暴露（46天; Et一NaCl）中，和（2 ）长期暴露，然后有恢复期（先在NaCl中暴露30天，然后在LB培养基中暴露16天； Et-R）。暴露后，E。toletana的敏感性通过将克隆种群暴露于6 NaCl浓度（掺有NaCl的LB培养基）和对照（LB培养基）来评估其对NaCl的种群。通过基于PCR的分子分型方法（BOX-PCR）评估基因型改变。结果表明，长期暴露后，通心粉对大肠杆菌的耐受性略有提高，生长的EC ₅₀为：Et-LB为22.5 g / L（8.64–36.4）； Et-LB为50。氯化钠Et-NaCl为30.3克/升（23.2–37.4）；Et-R为26.1 g / L（19.332.9）。在Et-LB和Et-R之间以及Et-NaCl和Et-R之间观察到了代谢活性的差异，这表明该细菌在盐碱化环境中使用了不同的底物。未检测到NaCl诱导的基因型改变。这项工作表明，E。toletana暴露于低盐度条件下，可以激活不同的代谢途径来应对渗透压。通过将这种细菌补充暴露于盐化作用的两栖动物自然种群的皮肤微生物组，可以进一步探索这些发现以用于生物强化程序。