Department of Biology, Aarhus University, Aarhus 8000, Denmark.
Department of Chemistry, Aarhus University, Aarhus 8000, Denmark.
Environ Sci Technol. 2024 Oct 29;58(43):19211-19221. doi: 10.1021/acs.est.4c01817. Epub 2024 Oct 19.
Airborne microorganisms impact cloud formation and are involved in disease spreading. The ability of airborne cells to survive and express genes may be limited by reduced water availability in the atmosphere and depend on the ability of the cells to attract water vapor at subsaturated conditions, i.e., their hygroscopicity. We assessed hygroscopic properties of the plant pathogen , known to participate in cloud formation. We used a hygroscopicity tandem differential mobility analyzer to examine both hydration and dehydration behavior in the relative humidity (RH) range 5-90%. The cells were aerosolized either from Milli-Q water or from a 35 g L NaCl solution, resulting in pure cells or cells associated with NaCl. Pure cells exhibited no deliquescence/efflorescence and a small gradual water uptake reaching a maximum growth factor (GF) of 1.09 ± 0.01 at 90% RH. For cells associated with NaCl, we observed deliquescence and a much larger maximum GF of 1.74 ± 0.03 at 90% RH. Deliquescence RH was comparable to that of pure NaCl, highlighting the major role of the salt associated with the cells. It remains to be investigated how the observed hygroscopic properties relate to survival, metabolic, and ice-nucleation activities of airborne .
空气中的微生物会影响云的形成，并参与疾病的传播。空气中细胞的生存和表达基因的能力可能会受到大气中水分减少的限制，并且取决于细胞在亚饱和条件下吸引水蒸气的能力，即它们的吸湿性。我们评估了已知参与云形成的植物病原体的吸湿性。我们使用吸湿串联差分迁移率分析仪在相对湿度 (RH) 范围 5-90% 内检查水合和脱水行为。细胞分别从 Milli-Q 水或 35 g L NaCl 溶液中气溶胶化，得到纯细胞或与 NaCl 结合的细胞。纯细胞没有潮解/反潮解现象，并且在 90% RH 时逐渐吸收少量水，达到最大生长因子 (GF)1.09±0.01。对于与 NaCl 结合的细胞，我们观察到潮解，并且在 90% RH 时最大 GF 达到 1.74±0.03。潮解 RH 与纯 NaCl 的 RH 相当，突出了与细胞相关的盐的主要作用。需要进一步研究观察到的吸湿性如何与空气中的生存、代谢和冰核活性相关。
