Volume 15, No. 2, April 2015, Pages 591-599 PDF(1.72 MB)
UV-Tolerant Culturable Bacteria in an Asian Dust Plume Transported over the East China Sea
Kazutaka Hara1, Daizhou Zhang1, Hiromi Matsusaki1, Yasuhiro Sadanaga2, Keisuke Ikeda3, Sayuri Hanaoka3, Shiro Hatakeyama3
1 Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, Kumamoto 862-8502, Japan
2 Graduate School of Engineering, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
3 Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
- Aircraft observations were conducted in western Japan during Asain dust passage and non-dust conditions in December 2010.
- The 34 culturable bacteria associated with Asian dust were isolated and could be grouped into Bacillales and Actinomycetales.
- Hihgly tolerant endospore-forming bacterial strains were predominant in the cultured bacterial composition.
- All non-endospore-forming bacteria in the composition were the strains having substantial tolerance for exposure to UV radiation.
Airborne bacteria are dispersed along with Asian dust and have various influences on atmospheric characteristics, downwind ecosystems, and public health. In this study, aircraft observations were conducted during Asian dust passage and non-dust conditions over the East China Sea in December 2010, and the composition of culturable bacteria within the dust was investigated using culture-based gene analysis. The 16S rRNA gene analysis revealed that the 34 cultured strains isolated from the transported dust could be grouped into Bacillales and Actinomycetales. Highly tolerant endospore-forming bacteria (25 isolates) were predominant in the composition. On the other hand, all non-endospore-forming bacteria (9 isolates) were gram-positive bacteria with high guanine and cytosine contents, which have substantial ultraviolet (UV) resistance. Thus, the isolated culturable bacteria were strains having some tolerance for exposure to UV radiation. Although the atmosphere is an extreme environment for bacterial survival, Asian dust can facilitate atmospheric dispersion of culturable bacteria that are resistant to the harsh ambient air environment.
Bioaerosols; Culturable bacteria; Asian dust; Long-range transport.