Assessing the short-term variability of bacterial composition in background aerosols of the Eastern Mediterranean during a rapid change of meteorological conditions

作者：Polymenakou P N^*; Mandalakis M

来源：Aerobiologia, 2013, 29(3): 429-441.

DOI：10.1007/s10453-013-9295-1

• 16S rRNA gene
• Airborne microorganisms
• Air mass origin
• Background aerosols
• Mediterranean Sea

This study used a PCR-based molecular identification technique to examine bacterial assemblage composition in background aerosols of the eastern Mediterranean Sea during a rapid change of meteorological conditions. 16S rDNA fragments of 166 clones were identified and were affiliated with six bacterial phyla (Firmicutes, Actinobacteria, Proteobacteria, Bacteroidetes, Spirochetes, and Fusobacteria), plant-related sequences, and other uncultivated bacterial groups. The analyzed clones were closely related to sequences previously characterized from diverse sources including soil, plants, marine water and sediment, human skin, activated sludge, house dust, indoor air, gut microbiota, and food. Plant- and human-associated sequences accounted for the largest fraction of the identified clones. Spore-forming Firmicutes showed a considerable increase when air mass origin changed from north to south implying that south winds favored bacterial spores transportation from the inland of Crete or North Africa. However, no conclusive trends were revealed for other groups of microorganisms. The influence of air mass origin was further investigated for marine- and terrestrial-associated sequences. A higher number of marine-associated sequences were identified when south winds crossed the inland of Crete, while the opposite was observed when north winds passed over the Aegean Sea. This discrepancy could be partly explained by the fact that the north winds were blowing at very low speed which constrained the formation of sea-spray aerosols and the ejection of marine microbes from sea surface to the atmosphere. Overall, the interpretation of bacterial assemblage composition in relation to the meteorological conditions was proved to be a complicated task which is in line with previous studies.

• 出版日期2013-9