Abstract:[Background] Recently, frequent haze events affect people’s daily life and economic development adversely. At present, less attention has been paid to airborne microorganisms in such haze events. [Objective] To explain the characteristics of airborne microbes in haze and further clarify the roles of microorganisms in the formation of haze. [Methods] Samples of particulate matter in severe haze in Beijing were collected. The microbial community structure and composition were analyzed by amplicon sequencing of bacterial 16S rRNA genes, and the correlations with pollutants were explored. [Results] Haze events would affect the airborne bacterial community structure significantly, resulted in an obvious increase of Proteobacteria and decrease of Actinobacteria. Particulate matter and the chemical constituents were identified as key factors that affected the α-diversity and community structure of airborne bacteria in severe haze. Meanwhile, compared with gaseous pollutants SO2 and NO2, water-soluble inorganic ions sulfate, nitrate and ammonium had a more obvious effect on airborne bacterial community structure. [Conclusion] This work illuminates the community characteristics of airborne bacteria in severe haze and its correlation with key environmental factors, and provides data references for airborne microbial research, air quality assessment and haze prevention.
