Katsivela Eleftheria, Chatoutsidou Sofia Eirini, Saridaki Aggeliki, Raisi Louiza, Stathopoulou Panagiota, Tsiamis Georgios, Kunfeng Gao, Fetfatzis Prodromos, Romanos Foskinis, Gidarakou Marilena, Gini Maria I, Granakis Konstantinos, Mylonaki Maria, Papanikolaou Christina, Vratolis Stergios, Vogel Francisca, Zografou Olga, Möhler Ottmar, Papayannis Alexandros, Eleftheriadis Konstantinos, Nenes Athanasios, Lazaridis Mihalis
Department of Electronic Engineering, Hellenic Mediterranean University, 3 Romanou st., Chania 73133, Greece.
Atmospheric Aerosols Laboratory, School of Chemical and Environmental Engineering, Technical University of Crete, University Campus, Chania 73100, Greece.
ACS Earth Space Chem. 2025 Jun 12;9(7):1801-1814. doi: 10.1021/acsearthspacechem.5c00064. eCollection 2025 Jul 17.
Cultural-based methods of bacteria and fungi and molecular identification of bacteria were combined with parallel continuous measurements of aerosol chemical composition, number size distribution, ice-nucleating concentration, and fluorescent particle size distribution and characteristics. Measurements took place at the Helmos Hellenic Atmospheric Aerosol and Climate Change Station (HAC), Greece, during the 2021 CALISHTO campaign. The objective was to characterize the microorganism levels at the (HAC) station and further investigate the associations between bioaerosols and aerosols in atmospheric processes that play a key role in the formation of ice crystals. Very low concentrations of viable, cultivable heterotrophic bacteria (4 ± 4 CFU/m) were measured, whereas fast-growing fungi were not affected (182 ± 86 CFU/m) by the environmental conditions at the station. The size distribution of heterotrophic bacteria was bimodal with peaks at fine (1.1-2.1 μm) and coarse size fractions ( > 7 μm), whereas airborne fungi exhibited a monomodal distribution (2.1-3.3 μm). Bacterial populations identified using 16S rRNA correlated well ( = 0.82) with the averaged concentrations of fluorescent particles (A and C channels). Strong correlations were obtained between total bacterial and particle volume concentrations of coarser fractions (>1 μm, 0.61-0.86), suggesting their strong presence in these sizes. No correlation was found with ice nuclei (INP) ( = -0.04) and low to medium negative correlations with the organics and ions (SO , NH , NO , Cl) possibly due to their relatively lower sizes. In accordance with the culture-dependent analysis, relatively low total bacterial concentrations were determined by real-time PCR, with concentrations ranging from 33.4 to 117.2 GE/m. High bacterial diversity was found with 123 bacterial Operational Taxonomy Units (OTUs) classified in 10 phyla, 16 classes, 56 families, and 78 genera. Origin of the air masses was a significant driver to bacterial communities. Enrichment of specific species such as and was observed during Saharan dust episodes, while in the presence of continental air masses, characteristic species such as ., ., and had higher relative abundance. Our study provides a comprehensive analysis and quantification of the varying drivers and variability in microorganisms in high-altitude site.
将基于培养的细菌和真菌方法以及细菌的分子鉴定与气溶胶化学成分、数量粒径分布、冰核浓度和荧光粒径分布及特征的并行连续测量相结合。测量于2021年CALISHTO活动期间在希腊的海尔莫斯希腊大气气溶胶与气候变化站（HAC）进行。目的是表征（HAC）站的微生物水平，并进一步研究大气过程中生物气溶胶与气溶胶之间的关联，这些过程在冰晶形成中起关键作用。测量到极低浓度的可存活、可培养的异养细菌（4±4 CFU/m），而快速生长的真菌不受该站环境条件的影响（182±86 CFU/m）。异养细菌的粒径分布呈双峰，在细粒径（1.1 - 2.1μm）和粗粒径部分（>7μm）有峰值，而空气传播的真菌呈现单峰分布（2.1 - 3.3μm）。使用16S rRNA鉴定的细菌种群与荧光颗粒（A和C通道）的平均浓度相关性良好（r = 0.82）。在较粗粒径部分（>1μm，r = 0.61 - 0.86）的总细菌浓度与颗粒体积浓度之间获得了强相关性，表明它们在这些粒径中大量存在。与冰核（INP）未发现相关性（r = -0.04），与有机物和离子（SO₄²⁻、NH₄⁺、NO₃⁻、Cl⁻）呈低到中等程度的负相关，可能是由于它们的粒径相对较小。与基于培养的分析一致，通过实时PCR测定的总细菌浓度相对较低，浓度范围为33.4至117.2 GE/m。发现了高细菌多样性，有123个细菌操作分类单元（OTU），分为10个门、16个纲、56个科和78个属。气团来源是细菌群落的一个重要驱动因素。在撒哈拉沙尘事件期间观察到特定物种如[具体物种1]和[具体物种2]的富集，而在大陆气团存在时，特征物种如[具体物种3]、[具体物种4]和[具体物种5]具有更高的相对丰度。我们的研究对高海拔地区微生物的不同驱动因素和变异性进行了全面分析和量化。
