Microbial characteristics of culturable fungi and bacteria in aerosol particles of a coastal region.

In this study, atmospheric bioaerosol particles were collected from March to December 2015 in the coastal region of Qingdao. The dominant fungi were identified, and the concentrations and size distributions of bacteria, total fungi and dominant fungi were measured. The most dominant fungal taxon was Cladosporium, followed by Alternaria, Penicillium and Aspergillus. The concentrations of fungi showed significant seasonal variation (p < 0.05) and peaked in summer, while bacterial concentrations peaked in autumn without significant seasonal differences. The particle size of fungi showed a similar normal distribution, peaking at 2.1 to 3.3 μm, while that of bacteria presented a skewed distribution pattern with a peak at > 7.0 μm. The size patterns of the four dominant fungi were distinct due to their respective properties. With correlation analysis, we found PM₁₀, CO and NO₂ were positively associated with the bacterial concentration. The factors correlated with fungal concentrations included temperature, relative humidity, CO, NO₂, SO₂ and O₃. The results of RDA showed that the most important meteorological factors affecting the microorganism species composition were temperature and relative humidity, and the dominant air pollutants were SO₂, CO and O₃. We selected related parameters to conduct multiple linear regression analysis to explore the synergistic effects on a given microorganism. The contribution to the rate of changes in bacterial and fungal concentrations caused by related factors was less than 30%, indicating that the sources and community changes had a great influence on bioaerosol concentrations. The more detailed the classification of microorganisms is, the more specific correlation information may be obtained through our analysis method. [ABSTRACT FROM AUTHOR]