[M-IS09] dust

[MIS09-03] Comparison of airborne microbial variations in air samples from Asian-dust source and arrival regions

*Teruya Maki¹, Tatsuyuki Fujita¹, Yuuma Mastuba¹, Yasunori Kurosaki², Masahide Ishizuka³, Kei Kawai⁴, Yasunobu Iwasaka⁵ (1.College of Science and Engineering, Kanazawa University, 2.Arid Land Research Center, Tottori University, Tottori University, 3.Faculty of Engineering, Kagawa University, 4.Graduate School of Environmental Studies, Nagoya Universit, 5.Center for Environmental Creative Studies )

Keywords:bioaerosol, long range transport, microorganisms

Aerosol dust is emerging as a significant vehicle for long-range transport of microorganisms. Nonetheless, many factors relating to this highly influential dispersal mechanisms remain unresolved, including the variation in dispersal bacterial communities during stochastic desert dust events, and the effect of aerosol transit over continental and oceanic surfaces to these communities. Here we elucidated bacterial 16S rRNA gene and fungal ITS-defined changes in airborne microbial communities at Asian-dust source regions (Gobi) and arrival regions (Japan) both lying along the trajectory for dust-event transport. Aerosols collected in the both regions generally reflected local origin from freshwater, marine, plant, or animal sources. In particular, dust events in the Gobi Desert increased these microbial cells and mineral particles to more than ten folds of concentrations. After dust-events occurrences in desert areas, the spore-forming microorganisms (bacteria: Bacillaceae, fungi: Davidiellaceae) and organic-aggregating bacteria (Cytophagaceae) showed high relative abundances, suggesting the survival of some microbes against strict atmospheric stressors over desert. These stress-resistance microbial populations were frequently dominated during Asian-dust evens over Japan, which are located cross China industrial area and Japan Sea. Presumably, atmospheric stressors over desert transit over deserts, anthropogenic polluted areas and oceanic waters strongly selects for airborne microbial populations through atmospheric stressors.