Gatta Elena, Abd El Elena, Brunoldi Marco, Irfan Muhammad, Isolabella Tommaso, Massabò Dario, Parodi Franco, Prati Paolo, Vernocchi Virginia, Mazzei Federico
Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, 16143, Genoa, Italy.
INFN - Sezione di Genova, Via Dodecaneso 33, 16143, Genoa, Italy.
Sci Rep. 2025 Mar 25;15(1):10320. doi: 10.1038/s41598-025-94898-y.
Airborne biological particles, such as pollen, fungi, bacteria, viruses, and plant or animal detritus, are known as bioaerosols. Understanding bioaerosols' behavior, especially their reaction to pollutants and atmospheric conditions, is crucial for addressing environmental and health issues related to air quality. Such complex investigations can benefit from experiments in controlled but realistic environments, such as the Atmospheric Simulation Chamber facility ChAMBRe (Chamber for Aerosol Modeling and Bio-aerosol Research). In this work, we report on the results of several experiments that were conducted at ChAMBRe using three strains of bacteria: E. coli, B. subtilis, and P. fluorescens. The goal of these experiments was to quantitively study how the culturability of these bacteria is affected by exposure to NO, NO, and light. The experimental approach was simple but carefully controlled: before being introduced into ChAMBRe, the bacteria samples were characterized using three different methods to determine the ratio of viable to total bacteria. The bacteria suspension was then aerosolized and introduced into ChAMBRe, where it was exposed to two different concentrations of NO and NO, in dark conditions and with simulated solar radiation. The culturability of the bacteria was assessed by collecting bacteria samples directly onto Petri dishes by an Andersen impactor at various time intervals after the end of injection. Finally, the formed bacteria colonies were counted after 24-48 h of incubation to measure their culturability and the temporal trend. The results show a reduction of culturability for all bacteria strains when exposed to NO (from 50 to 70%) and to high concentrations of NO (i.e. around 30% at more than 1200 ppb) at concentration values higher than the typical urban ambient values. Even higher effects were observed exposing the bacteria strain to a proxy of solar light. The findings show how atmospheric simulation chambers help the comprehension of interactions between pollutants and bioaerosols in controlled atmospheric environments.
空气传播的生物颗粒，如花粉、真菌、细菌、病毒以及动植物碎屑，被称为生物气溶胶。了解生物气溶胶的行为，尤其是它们对污染物和大气条件的反应，对于解决与空气质量相关的环境和健康问题至关重要。此类复杂的研究可以从在可控但逼真的环境中进行的实验中受益，例如大气模拟舱设施ChAMBRe（气溶胶建模与生物气溶胶研究舱）。在这项工作中，我们报告了在ChAMBRe使用三种细菌菌株（大肠杆菌、枯草芽孢杆菌和荧光假单胞菌）进行的几个实验的结果。这些实验的目的是定量研究这些细菌的可培养性如何受到暴露于一氧化氮、二氧化氮和光的影响。实验方法简单但经过精心控制：在将细菌样本引入ChAMBRe之前，使用三种不同方法对其进行表征，以确定活菌与总细菌的比例。然后将细菌悬浮液雾化并引入ChAMBRe，在黑暗条件下和模拟太阳辐射下使其暴露于两种不同浓度的一氧化氮和二氧化氮中。在注射结束后的不同时间间隔，通过安德森撞击器将细菌样本直接收集到培养皿上，以评估细菌的可培养性。最后，在孵育24 - 48小时后对形成的细菌菌落进行计数，以测量其可培养性和时间趋势。结果表明，当暴露于浓度高于典型城市环境值的一氧化氮（可培养性降低50%至70%）和高浓度二氧化氮（即超过1200 ppb时约为30%）时，所有细菌菌株的可培养性都会降低。当将细菌菌株暴露于太阳光模拟物时，观察到的影响甚至更大。这些发现表明大气模拟舱有助于理解在可控大气环境中污染物与生物气溶胶之间的相互作用。
