AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Bacterial Aerosol Concentration Associated with Dust Passage at Southwestern Japan Observed in 2010-2014
KOTARO MURATA, Kazutaka Hara, Daizhou Zhang, Prefectural University of Kumamoto
Abstract Number: 124 Working Group: Bioaerosols
Abstract Bacteria as prominent biological particles in the atmosphere affect climate and global hydrological cycles by acting as nuclei of ice-cloud formation, and the constant dispersal of viable bacteria is regarded as a link between disjunctive bacterial communities in distant areas. In this presentation, we present the measurements in southwestern Japan to show that concentrated bacteria are widespread with Asian dust plumes. Airborne particulate matter was collected in the campus of the Prefectural University Kumamoto, Kumamoto, Japan (32°48'N, 130°45'E) and at a seaside in Amakusa, Japan (32°19'N, 129°59'E) during dust and non-dust periods in 2010-2014. Collected samples were stained with LIVE/DEAD BacLight Bacterial Viability Kits for separately labeling viable and non-viable bacterial cells. Coarse particles (>1 µm) measured with an optical particle counter were used to show the arrival of Asian dust. The number concentration of bacteria in dust plumes varied between 1.0 × 10$^6 and 1.6 × 10$^7 cells m$^(-3), which was one to two orders larger than that in non-dust air and was proportional to and comparable to the concentration of particles larger than 1 μm. The viability of bacteria was 16-40% in dust plumes, which was quite smaller than the 76-91% viability in non-dusty air. However the absolute concentration of viable bacteria in dust plumes, 2.5 × 10$^5-3.8 × 10$^6 cells m$^(-3), was similar to or larger than those in non-dusty air. Dust is thus a substantial medium for bacteria to link the isolated communities in addition to ice nucleating activities.