Phylogenetic Diversity and Vertical Distribution of a Halobacterial Community in the Atmosphere of an Asian Dust (KOSA) Arrival Region, Suzu City

抄録

The microbial communities transported by Asian desert dust (KOSA) events have attracted much attention as bioaerosols because the transported microorganisms are thought to influence the downwind ecosystems in Korea and Japan. Bioaerosol samples were collected at 10 and 600 m above the ground within the KOSA arrival area, Suzu City, Japan, during KOSA coming season. The microorganisms in bioaerosol samples grew in media containing up to 15 % NaCl, suggesting that bacteria tolerant to high salinities remain viable in the atmosphere. Denaturing gradient gel electrophoresis using 16S rDNA sequences revealed that the viable halobacterial communities in the bioaerosol samples were composed of members of the genus Bacillus. Moreover, the relative bacteria of B. subtilis was found to dominate in the atmosphere at 600 m and detected from a culture amended with 10% NaCl of aerosol sample at 10 m. Presumably, active mixing processes of the boundary layer transport viable halotolerant bacteria from the atmosphere to the ground surface in Suzu City, where the long-range KOSA particle transport from China is frequently observed.