Development of methods for quantifying bacteria on dust particles

2014 Fiscal Year Final Research Report

• Project/Area Number: 25550017
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Environmental dynamic analysis
• Research Institution: Prefectural University of Kumamoto
• Principal Investigator: ZHANG Daizhou 熊本県立大学, 環境共生学部, 教授 (90322726)
• Co-Investigator(Kenkyū-buntansha): MAKIKO Kakikawa 金沢大学, 学内共同利用施設等, 助教 (10359713) ; HIROMI Matsusaki 熊本県立大学, 環境共生学部, 教授 (30326491)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 環境変動 / 大気現象 / バイオエアロゾル / 黄砂 / 浮遊微生物 / 東アジア / 陸間移動 / 微生物生態系

Outline of Final Research Achievements

An approach to quantify the airborne bacteria long-distance transported with dust was developed and applied to the observation on the Kyushu western coast. Results showed that the concentration of airborne bacteria was approximately stable in the range of 10000 ~ 100000 cells per cubic meters but the viability differed largely under different weather conditions. Under high pressures, about 83% of bacteria were isolated from particles and their viability was about 74%. In the prefrontal air of low pressures, the ratio of isolated bacteria was about 56% and their viability was 88%. In contrast, in dry and cold continentally-originated air, 72% of bacteria were associated with dust particles and their viability was less than 50%. These results indicate the close dependence of airborne bacteria on the synoptic weather at the coastal areas of Kyushu where the weather was governed by the alternative passage of low and high pressures in the northern hemisphere westerly winds.

Free Research Field

大気環境学