This study investigates the inactivation kinetics of ATCC 14579 (endospores) ATCC 25922 when exposed to UV-C light at varying wavelengths (254, 265, 279, and 284 nm). Two scenarios were investigated: stirred liquid suspensions and unstirred static settings (droplets on stainless steel surfaces). The results reveal that the UV-C transmittance through microbial suspensions follows order of 284 > 279> 254 > 265 nm. In stirred conditions, the inactivation kinetics of microbial suspensions exhibited a correlation with the absorption spectra, leading to inactivation kinetic constants order: 265 > 254>279 > 284 nm. However, when focusing on comparative studies of inactivation under unstirred conditions, a different order emerged: 265 > 279>284 > 254 nm. Notably, the overall trend revealed that inactivation kinetic constants tend to be higher in unstirred settings, apart from the 254 nm. These variations in inactivation order and kinetic constants can be attributed to enhanced protein damage at wavelengths 265, 279, and 284 nm under unstirred conditions compared to stirred. In summary, we observed effective germicidal efficiency of UV-C light at 265 nm, in both experimental conditions. However, for experimental conditions involving low light transmission through microbial structures such as biofilms, wavelengths of 279 and 284 nm holds considerable promise, ensuring efficient light penetration and enhanced inactivation efficiency.

中文翻译：

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接触表面搅拌液体悬浮液和液滴中食源性病原体的波长特定 UV-C 灭活动力学

本研究研究了 ATCC 14579（内生孢子）ATCC 25922 在暴露于不同波长（254、265、279 和 284 nm）的 UV-C 光时的失活动力学。研究了两种情况：搅拌的液体悬浮液和未搅拌的静态设置（不锈钢表面上的液滴）。结果表明，微生物悬浮液的 UV-C 透过率依次为 284 > 279 > 254 > 265 nm。在搅拌条件下，微生物悬浮液的失活动力学表现出与吸收光谱的相关性，导致失活动力学常数顺序：265 > 254 > 279 > 284 nm。然而，当重点关注未搅拌条件下失活的比较研究时，出现了不同的顺序：265 > 279 > 284 > 254 nm。值得注意的是，总体趋势表明，除 254 nm 外，在未搅拌的环境中失活动力学常数往往较高。失活顺序和动力学常数的这些变化可归因于与搅拌相比，在未搅拌条件下，波长 265、279 和 284 nm 处的蛋白质损伤增强。总之，我们在两种实验条件下观察到 265 nm UV-C 光的有效杀菌效率。然而，对于涉及生物膜等微生物结构的低光透射率的实验条件，279 和 284 nm 的波长具有相当大的前景，可确保有效的光穿透和增强的灭活效率。